Mineralogy and Geochemistry of Shale Deposits in the Lower Anambra Basin, Nigeria: Implication for Provenance, Tectonic Setting and Depositional Environment

Olugbenga Okunlola(Olugbenga Okunlola ),Agonsi Udodirim Lydia(Agonsi Udodirim Lydia ),Aliyu Ohiani Umaru(Aliyu Ohiani Umaru ),Raymond Webrah Kazapoe(Raymond Webrah Kazapoe ),Olusegun G. Olisa(Olusegun 대한자원환경지질학회 2023 자원환경지질 Vol.56 No.6

Mineralogical and geochemical studies of shales within the Lower Anambra Basin was conducted to unravel the depositional environment, provenance, maturity, paleo-weathering conditions, and tectonic settings. Mineralogical studies conducted using X-ray diffraction analysis revealed that the samples were composed of kaolinite, montmorillonite, chlorite, and illite. KaolinIite is the dominant mineral, constituting approximately 41.5% of the bulk composition, whereas the non-clay minerals are quartz, ilmenite, and sillimanite. Geochemical analysis showed a predominance of SiO2, Al2O3, and Fe2O3 contents of the shale samples with mean values of 52.29%, 14.09%, and 6.15% for Imo Shale (IS); 52.31%, 16.70%, and 7.39% for Mamu Shale (MS); 43.21%, 21.33%, and 10.36% for Enugu Shale (ES); 53.35%, 15.64%, and 7.17% for Nkporo Shale (NS); and 51.24%, 17.25%, and 7.78% for Agwu Shale (AS). However, the shales were depleted in Na2O, MgO, K2O, MnO, TiO2, CaO, and P2O5. The trace element ratios of Ni/Co and Cu/Zn of the shale suggest an oxic depositional environment. The average SiO2 vs. Al2O3 ratio of the shales indicated textural maturity. Compared to the PAAS standard, the shales plot below the PAAS value of 0.85, suggesting a high degree of maturity and intensive chemical weathering, further confirmed on a CIA vs. PIA plot. On log (K2O/Na2O) against SiO2 and tectonic setting discriminant function diagrams, the shales plot mostly in the field of passive continental margin tectonic setting. The discriminant function diagrams as well as Al2O3/TiO2 ratio of the shales showed that they were derived from a mixed source (mafic and intermediate igneous rocks).

Development of ibuprofen microspheres using acetylated plantain starches as polymer for sustained release

Adenike Okunlola,Tokoni Ghomorai 한국약제학회 2018 Journal of Pharmaceutical Investigation Vol.48 No.5

Ibuprofen has a short half-life (1–3 h) and is typically administered 3–4 times daily with subsequent adverse side effects. A good approach to reduce these effects is the preparation of sustained-release formulations of ibuprofen. Acetylated starches form water-insoluble, acid-resistant films that can substantially retard drug release. Ibuprofen microspheres were prepared using acetylated plantain starch as sustained-release polymer. Starch obtained from unripe plantain (Musa Paradisiaca normalis) were acetylated using acetic anhydride with pyridine (degrees of substitution, DS 1.5 ± 0.05 and 2.20 ± 0.10). The starches were characterized using morphology, crystallinity, swelling, density and flow properties. Ibuprofen microspheres were prepared by quasi-emulsion solvent diffusion method, using acetylated plantain starches DS 1.5 and 2.20 in comparison to Eudragit S100. Full 32 factorial experimental design was performed with polymer type ( X1), polymer: drug ratio ( X2) as independent factors; microsphere size, entrapment, and quantity of drug released in 12 h ( Q12) were dependent variables. The data from in vitro drug release were fitted to various kinetic models. Acetylation resulted in larger starch aggregates with disruption in crystalline order. Ibuprofen microspheres were spherical with size 5.50 ± 4.00–129.90 ± 12.97 μm. Drug entrapment was 43.92 ± 4.00–79.91 ± 6.15%. Values of Q12 ranged from 20.10 ± 0.55 to 54.00 ± 5.71%. Interaction between variables X1 and X2 had positive effects on size and entrapment. Drug release fitted zero order, first order and Baker-Lonsdale kinetic models. Acetylated starch of plantain with DS 2.20 was suitable as a polymer at polymer:drug ratio 4:1 for the formulation of ibuprofen microspheres with prolonged drug release.

Modeling the relationship between malaria prevalence and insecticide-treated bed net coverage in Nigeria using a Bayesian spatial generalized linear mixed model with a Leroux prior

Oluyemi A. Okunlola,Oyetunde T. Oyeyemi,Adewale F. Lukman 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: To evaluate malaria transmission in relation to insecticide-treated net (ITN) coverage in Nigeria. METHODS: We used an exploratory analysis approach to evaluate variation in malaria transmission in relation to ITN distribution in 1,325 Demographic and Health Survey clusters in Nigeria. A Bayesian spatial generalized linear mixed model with a Leroux conditional autoregressive prior for the random effects was used to model the spatial and contextual variation in malaria prevalence and ITN distribution after adjusting for environmental variables. RESULTS: Spatial smoothed maps showed the nationwide distribution of malaria and ITN. The distribution of ITN varied significantly across the 6 geopolitical zones (p<0.05). The North-East had the least ITN distribution (0.196±0.071), while ITN distribution was highest in the South-South (0.309±0.075). ITN coverage was also higher in rural areas (0.281±0.074) than in urban areas (0.240±0.096, p<0.05). The Bayesian hierarchical regression results showed a non-significant negative relationship between malaria prevalence and ITN coverage, but a significant spatial structured random effect and unstructured random effect. The correlates of malaria transmission included rainfall, maximum temperature, and proximity to water. CONCLUSIONS: Reduction in malaria transmission was not significantly related to ITN coverage, although much could be achieved in attempts to curtail malaria transmission through enhanced ITN coverage. A multifaceted and integrated approach to malaria control is strongly advocated.

Geochemistry and Petrogenesis of Pan-african Granitoids in Kaiama, North Central, Nigeria

Aliyu Ohiani Umaru(Aliyu Ohiani Umaru ),Olugbenga Okunlola(Olugbenga Okunlola ),Umaru Adamu Danbatta(Umaru Adamu Danbatta ),Olusegun G. Olisa(Olusegun G. Olisa ) 대한자원환경지질학회 2023 자원환경지질 Vol.56 No.3

Pan African granitoids of Kaiama is comprised of K-feldspar rich granites, porphyritic granites, and granitic gneiss that are intruded by quartz veins and aplitic veins and dykes which trend NE-SW. In order to establish the geochemical signatures, petrogenesis, and tectonic settings of the lithological units, petrological, petrographical, and geochemical studies was carried out. Petrographic analysis reveals that the granitoids are dominantly composed of quartz, plagioclase feldspar, biotite, and k-feldspar with occasional muscovites, sericite, and opaque minerals that constitute very low proportion. Major, trace, and rare earth elements geochemical data reveal that the rocks have moderate to high silica (SiO2=63-79.7%) and alumina (Al2O3=11.85-16.15) contents that correlate with the abundance of quartz, feldspars, and biotite. The rocks are calc-alkaline, peraluminous (ASI=1.0-<1.2), and S-type granitoids sourced by melting of pre-existing metasedimentary or sedimentary rocks containing Al, Na, and K oxides. They plot dominantly in the WPG and VAG fields suggesting emplacement in a post-collisional tectonic setting. On a multi-element variation diagram, the granitoids show depletion in Ba, K, P, Rb, and Ti while enrichment was observed for Th, U, Nd, Pb and Sm. Their rare-earth elements pattern is characterized by moderate fractionation ((La/Yb)N=0.52-38.24) and pronounced negative Eu-anomaly (Eu/Eu*=0.02-1.22) that points to the preservation of plagioclase from the source magma. Generally, the geochemical features of the granitoids show that they were derived by the partial melting of crustal rocks with some input from greywacke and pelitic materials in a typical post-collisional tectonic setting.

ON THE INTERACTION BETWEEN EXPORT PROMOTION AND AGRICULTURAL GROWTH IN POVERTY REDUCTION IN NIGERIA: EMPIRICAL EVIDENCE FOR THE PERIOD 1980-2016

AKINLO ANTHONY ENISAN,OKUNLOLA CHARLES OLALEKAN 중앙대학교 경제연구소 2022 Journal of Economic Development Vol.47 No.1

This paper examines the interactive effect of export promotion policies and agricultural output growth on the poverty level in Nigeria for the period 1980 to 2016 using the Autoregressive Distributed Lag Approach (ARDL) approach. Our results can be summarized as follows. First, the interaction of export promotion and agricultural output growth is associated with a lower poverty level in Nigeria in the long and short run. Second, agricultural output growth has a poverty-reducing effect in Nigeria in the long run. Three, export promotion policies aid poverty reduction in the long run. Finally, non-agricultural output growth, inflation, and population growth increase poverty in Nigeria. The findings from the study underlie the importance of integrating agricultural output growth and export promotion schemes in poverty-alleviation process in Nigeria.

Petrographic Study of Mn-bearing Gondite (Birimian) of Téra Area in the Leo-Man Shield (West African Craton) in Niger.

Hamidou GARBA SALEY,Moussa KONATÉ,Olugbenga Akindeji OKUNLOLA 대한자원환경지질학회 2024 자원환경지질 Vol.57 No.1

The Téra manganese deposit represents the most significant manganese mineralization discovered in Niger up today. The main host rocks of this ore are gondites, which are a garnet and quartz rich metamorphic rocks. The supergene weathering developed an alteration profile on these gondites. This study aims to identify the mineralogical composition of gondites and associated rocks, in order to highlight the origine of rocks and the manganese enrichment. The methodological approach adopted involved a field study followed by polarizing microscopic analysis using transmitted and reflected lights. Additionally, quantitative X-ray diffraction (XRD) analysis was performed to assess the manganese ore minerals present in the gondite and associated rocks, including mica schists, amphibolites, and quartzites. The petrographic study revealed a paragenesis characterized by the presence of kyanite, staurolites, garnets and plagioclases that are generally poikiloblasts with quartz and opaque minerals inclusions, emphasizing the internal schistosity which is planar, helicitic or microfolded. These features indicate a prograde metamorphism until high-pressure amphibolite facies conditions. These conditions are followed by greenschist facies conditions marked by calcite, epidote, muscovite, chlorite and muscovite assemblage which emphasizes the vertical tectonics. Depending on the alteration process, the manganese ore exhibit a granular texture at the bottom of the gondite hills, transitioning to a colloform texture towards the top, passing through the epigenization and replacement texture. The XRD analysis further revealed that the studied rocks originated from a volcanosedimentary complex, characterized by alternating marly, arenaceous and pelitic sequences associated with submarine exhalations.

Formulation of floating metronidazole microspheres using cassava starch (Manihot esculenta) as polymer

Oluwatoyin A. Odeku,Aderemi A. Aderogba,Tolulope O. Ajala,Olufunke D. Akin‑Ajani,Adenike Okunlola 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.5

Floating gastroretentive microspheres have been used to prolong the gastric residence time after oral administration and improve the local effect of metronidazole in the stomach in the treatment of peptic ulcer caused by Helicobacter pylori. In the present study, cassava starch, obtained from the tubers of Manihot esculenta has been pregelatinized and used as polymer in combination with sodium alginate for the formulation of floating gastroretentive metronidazole microspheres. Metronidazole microspheres were prepared by ionic gelation method using pregelatinized cassava starch and sodium alginate at different concentrations as polymers and calcium chloride (2% w/v) as chelating agent. Sodium bicarbonate (2% w/w) was used as gas releasing agent. Microspheres were characterized using the particle size, swelling index, floating lag time (FLT), total floating time and drug release properties. Spherical discrete microspheres with size ranging from 1.52 to 2.23 mm were obtained with FLT of less than 5 min and drug entrapment efficiency of 42–60% w/w. The microsphere maintained buoyancy for over 19 h and the microspheres provided controlled release of metronidazole for up to 18 h. Drug release from the microspheres, swelling index and buoyancy depended on the concentration of cassava starch in the polymer blend. Formulations containing high concentration of cassava starch showing shorter floating lag time and faster drug release. Thus, buoyancy and rate of drug release appeared to be modulated by the concentration of cassava starch in the polymer blend. The results showed that pregelatinized cassava could be useful in the formulation of floating gastroretentive metronidazole microspheres.