Table of Contents

Phytoremediation of Copper, Zinc, Lead and Manganes from Contaminated Soil

using Hibiscus Sabdarifa Plant.

S.T.Magili  C.George Y.K.Musa¹ D.Y.Shingu………………………………………………………………….….                 1- 9

Density Functional Theoretical Calculations and Comparisons of Phonon Dispersion

Relations of Elemental Semiconductors.

R. A. Amusa  and O. E. Oyewande …………………………………………………………………….………..… 10-16

Seasonal Box-Jenkins Modelling of Nigerian Monthly Crude Oil Exports

Ette Harrison Etuk …………………………………………………………………………………………………..………           17-25

Application of Regression and Multiple Correlation Analysis to Morning Hours

 Solar Radiation in Lapai

Agbo G. A., Alfa B; Ibeh G. F. and Adamu I. S.…………………………………………….….……………             26-29

APPLICATION OF REGRESSION AND MULTIPLE CORRELATION ANALYSIS TO MORNING HOURS SOLAR RADIATION IN LAPAI

Agbo¹ G. A., Alfa² B; Ibeh G. F. and Adamu² I. S.

¹Department of Industrial Physics, Ebonyi State University, Abakaliki

²Department of Physics, Ibrahim Badamasi Babangida University, Lapai

e-mail: agbogodwina@yahoo.com

ABSTRACT

Solar radiation in Lapai within the morning hours has been estimated by correlating meteorological parameters. This was achieved by applying the first and second order regression and multiple correlation analysis method. The correlation coefficient based on the first and second order equations in temperature and relative humidity were 0.828, 0.692, 0.860 and 0.622 while the correlation coefficient based on the multiple correlations between solar radiations, temperature and relative humidity were 0.351. Validity tests were carried our using mean bias error (MBE), root mean square error (RMSE) and mean percentage error (MPE). The tests show that the errors were minimal in the first order equations in temperature and relative humidity. Comparison of the measured and predicted values of solar radiation based on the relative humidity and average temperature first order equations show a close agreement, and suggests the best equations to be used in estimating solar radiation in Lapai and its similar climatic condition.

Keywords: Solar radiation, multiple regression, correlation coefficient, meteorological parameter-temperature and relative humidity.

SEASONAL BOX-JENKINS MODELLING OF NIGERIAN MONTHLY CRUDE OIL EXPORTS

Ette Harrison Etuk

Department of Mathematics/Computer Science,

Rivers State University of Science and Technology, Nigeria

Email: ettetuk@yahoo.com

ABSTRACT

The time plot of the original series NCOE reveals a negative secular trend between 2006 and 2009 after which the trend tends to be increasing up to 2011. Seasonality is not so evident. A twelve-month (i.e. seasonal) differencing was done to yield the series SDNCOE with a generally positive trend and not so regular seasonality. Further nonseasonal differencing yielded a series DSDNCOE with no trend. Its correlogram reveals a seasonality of order 12, a seasonal moving average component of order 1 and an autocorrelation structure of a (0, 1, 1)x(0, 1, 1)₁₂ model. Therefore the model was proposed and fitted to the series. Diagnostic checking results show that the model is adequate.

Keywords: Seasonal Models, Box-Jenkins methodology, Crude Oil Exports, Nigeria.

DENSITY FUNCTIONAL THEORETICAL CALCULATIONS AND COMPARISONS OF PHONON DISPERSION RELATIONS OF ELEMENTAL SEMICONDUCTORS.

R. A. Amusa¹  and O. E. Oyewande²

¹Department of Science Laboratory Technology, Federal Polytechnic, Ilaro, Nigeria

²Department of Physics, University of Ibadan. Ibadan, Nigeria.

ABSTRACT

Phonon dispersion relations of semiconductor crystal frequencies at some high symmetry points were reported. A first principles method based on density functional perturbation theory (DFPT) as embedded in the Quantum Espresso (QE) simulation software was used. Appropriate equilibrium lattice constants and energy cut-offs needed for the calculations were deducted from the results of convergence tests carried out for the elements used. Effects of the local density approximation (LDA) and generalized gradient approximation (GGA) exchange correlation potentials at each of the high symmetry lines were compared. Our results of the phonon relations compare favourably well with those obtained in similar published researches. The result also showed that magnitude of phonon frequencies (both optical and acoustic) decrease from carbon to tin and in fact the ratio is 3:1 for Carbon: Silicon.

Keywords:   Quantum Espresso, dispersion relations, high symmetry points, exchange correlation potentials.

PHYTOREMEDIATION OF COPPER, ZINC, LEAD AND MANGANES FROM CONTAMINATED SOIL USING HIBISCUS SABDARIFA PLANT

S.T.Magili¹  C.George¹ Y.K.Musa¹ D.Y.Shingu¹

Department of Chemistry, Adamawa State University, Mubi, Nigeria.

email:smagilli@yahoo.com.

ABSTRACT

Bioaccumulation of heavy metals was studied using Hibiscus sabdarifa plant in a green house to investigate the absorption of copper (Cu), Lead (Pb) Zinc (Zn) and manganese (Mn) on a contaminated soil. Garden healthy soil samples were contaminated with various concentrations of these metals and H.Sabdarifa plant were grown on it in a pot for a period of 60 days. The roots and shoots organ of the plants were harvested and the samples were prepared and analyzed using Atomic Absorption spectrophotometer (AAS) in order to find out their phytoremediation potential. Result showed that heavy metal content in the plant tissue; roots stem and leaves were as follows: Cu1.00, 0.70, 0.60, (mg/kg), Zn, 5.2, 4.2, 2.00 (mg/kg),Pb  0.9,0.6, 0.5, (mg/kg),and Mn 1.50, 0.20 0.10 ( mg/kg) respectively. All the metals tend to accumulate mostly on the roots, stems and leaves and therefore decrease transfer probability to secondary consumers. Also the concentrations of heavy metals in the control samples were analyzed and compared. The results suggest that H. Sabdarifa plant could be used for the phytoremediation of copper, zinc, lead and manganese.

Keywords: Hibiscus sabdarifa,heavy metals,bioaccumulation phytoremediation