Gwandu Basiru Shehu

Title: Site Optimization for Biofuel Production Facilities in Nigeria Using GIS and Remote Sensing Technologies.

Gwandu Basiru Shehu, currently obtained a master’s degree in Geographical Information System.

Abstract:  Nigeria is one of the areas in the world where the problem of land availability for biofuel production may not be pronounced. This is because about 66% of agricultural land in the Country is not cultivated. The Nigeria Biofuel Policy (2007) stipulated that one of the responsibilities of the Ministry of Agriculture is to support land acquisition and utilisation strategies by biofuel companies. The aim of this reseach project was to optimize sites for biofuel production facilities in the Country based on some selected crops. Datasets such as meteorological records, satellite imagery, maps and Shapefiles were gathered from varios sources and a nominal scale of 1: 250,000 was used because raster cell size used for all the raster datasets was 100 metres. Multi-criteria evaluation (MCE) was the methodology employed and implemented in GIS environment. A total of seven models were developed. The first model excluded constraints from the analysis by eliminating the factors that hinder the establishment of a farm or a biofuel production facility. The second, the third and the fourth models identified suitable areas for cultivation of Sweet sorghum, Sugarcane and Jatropha, respectively by weighting the input parameters using Analytical Hierarchy Process (AHP) and implemented through a weighted overlay function. Fifth, sixth and seventh models optimized suitable locations for Sweet sorghum-based, Sugarcane-based and Jatropha-based biofuel production facilities by employing service area modelling through network analysis. Mashegu Local Government Area of Niger State was found to be the most ideal location for a Sweet sorghum – based biofuel production facility in Nigeria with a total of 11,371Gg within 200km of supply area. Demsa Local Government Area of Adamawa State was concluded to be the most ideal location for sugarcane-based biofuel production facility with a total of 15,150Gg of feedstock supply within 200km. While Toro Local Government Area of Bauchi State was the optimized location for a Jatropha – based biodiesel production facility in Nigeria with a total of 13,085Gg of feedstock within the same supply area extent.


Ihegwuagu Nnemeka Edith

Title: Slow Release Formulations of Chlorpyrifos and Dichlorvos Insecticides using Native starch and Starch-Silver Nanoparticles as Matrices

Ihegwuagu Nnemeka Edith, currently obtained her Doctor of Philosophy (Ph.D.) in Agrochemical Technology.

Abstract: This study deals with slow release formulations (SRF) of chlorpyrifos and dichlorvos using native starch and starch-silver nanoparticles as matrices. The native starch was isolated from cassava and maize while starch-silver nanoparticles (ST-AgNPs) were obtained via chemical reduction of silver nitrate by glucose at 90oC. For the starch-silver nanoparticles, synthetic parameters (time, concentration of matrix and reactants and their volume ratio) were optimized and monitored with UV-Vis spectrophotometer for their Surface Plasmon Resonance (SPR) to confirm the success of the synthesis. Both matrices were characterized by UV –Visible Spectrophotometry, Fourier Transform- Infrared (FT-IR), Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HR-TEM), Energy Dispersive X-Ray (EDX), Selected Area Electron Diffraction (SAED), Powder X-Ray Diffractometry (PXRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The SPR of cassava starch silver nanoparticle (CVNPs) was 403 nm while that of maize (MZNPs) peaked at 406 nm. Their morphology was spherical, mono dispersed with an average size range of 7-11 nm. EDX, SAED and PXRD confirmed the presence of silver (Ag) with the revelation of reflections indexed as (111), (200), (220) and (311) with the corresponding 2θ values of 38.4O, 44.4O, 64.1O and 77.7O respectively. The same method was applied in the in situ encapsulation of chlorpyrifos (FOS) and dichlorvos (VOS) insecticides onto the matrices to form native and nanoinsecticidal composites, respectively. The insecticide loaded ST-AgNPs were also characterized by UV–Visible Spectrophotometry, FT-IR, FESEM, HR-TEM, EDX, SAED, PXRD, DSC and TGA. Their absorption maxima were broad peaks in the range 406 – 422 nm due to SPR of silver. HR-TEM and FESEM images of ST-AgNPs-VOS/FOS showed spherical particles with average particle sizes in the range of 23-60 nm, while X-ray diffraction analysis, EDX, SAED and DSC spectra indicated that chlorpyrifos and dichlorvos were present in crystalline forms in the nanosilver formulations. Encapsulation efficiency was higher in the nanomatrices (95-98%) than in the native starch formulations (56–78%) for both insecticides. Release studies, carried out in water and three soil types, indicated a 10 – 31 % release of dichlorvos in the ST-AgNPs and 6 – 20% in the native starch (cassava) formulations, respectively at the end of 1 – 21 days in water; for maize starch-based formulations, the release data were 18 – 45% and 10 – 23 %, respectively for the same period, indicating an enhancement of insecticide release in the nanoformulation compared to native starch. This enhancement is attributed to the increase in surface area of the ST-AgNPs, compared to the native starch. Insecticide release in soil was in the order sandy-loam > sandy-clay-loam > clay-loam. Similar trends were observed for Chlorpyrifos. Various kinetics models including zero, first and pseudo-second-order kinetics as well as Higuchi models were applied to the experimental data to predict the release kinetics. Pseudo-second-order kinetics model gave the best fit with R2 = 0.97 for CVNPsVOS and 0.99 for CVNPsFOS in cassava-starch stabilized matrix and R2= 0.95 for MZNPsVOS and 0.98 for MZNPsFOS in maize-starch stabilized matrix. These studies showed that, while maize and cassava starch form good matrices for slow release formulations of chlopyrifos and dichlorvos, introduction of nanosilver into the matrix leads to an enhancement of the release of active ingredient with enhancement factors of 1.36-1.96.

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