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Background: The demand for vegetable oils is on the increase. Deep frying is the commonest method by which vegetable oils are consumed. The aim of this study was to extract oil from an underutilized oil seed and compare its physicochemical properties, frying, and oxidative stability with those of commercial refined palm oil. Methods: Oil was extracted from Monodora myristica seeds using a soxhlet fat extractor and the percentage oil yield was determined. The physicochemical, oxidative, and frying stabilities of the extracted M. myristica Seed Oil (MMSO) were evaluated based on the standard procedure of the Association of Official Agricultural Chemists and official methods and recommended practices of the American Oil Chemists Society and compared with those of commercial refined palm oil-Kings Vegetable Oil (KVO). Data were statistically analyzed using SPSS version 20. Results: The oil yield of M. myristica seed was 37.64%. The refractive index, specific gravity, moisture content (%), and peroxide value (mEq/kg) were respectively 1.470, 1.468, 0.923, and 0.917 for MMSO; and 0.220, 0.253, 1.05, and 3.50 for KVO. MMSO had better oxidative stability and showed 80% lesser peroxide formation than KVO. The frying stability of MMSO was better as it showed a lower increase in FFA (28.4%) and peroxide value (9.54 mEq/kg) than KVO (45.99% and 26.19 mEq/kg, respectively) after frying. Conclusion: Deteriorative effect of oxidation and polymerization was lower in MMSO than in KVO indicating MMSO to be superior frying oil suitable for repeated frying. [ABSTRACT FROM AUTHOR]

This study is concerned with the persistent underperformance of secondary school students in Nigeria in physics. The study was conducted in two phases. Phase one was a survey of difficult concepts in physics, while phase two explored the potency of culturo-techno-contextual approach (CTCA) in breaking the barriers to meaningful learning of refractive indices, which ranked the most difficult concept in phase one of the study. A total of 1621 SS3 students from Nigeria and Ghana participated in the survey phase. The second phase employed a mixed-methods approach (quasi-experimental and interviews) with a total of 205 SS1 students. The control group was taught with the lecture method and had 96 students (54 males; 42 females), while the experimental group, taught with CTCA, had 109 students (65 females; 44 males). Both groups had a pretest and posttest using the achievement test in refractive indices; treatment lasted four weeks. Data gathered in the survey were analyzed using mean rank analysis, and refractive indices was perceived as the most difficult to learn. Phase two data were analyzed using one-way ANCOVA since intact classes were used. The result obtained showed that the experimental group performed better (mean for experimental = 15.49; control 11.97; F (1, 202) = 64.48; p < 0.01)) than the control group. Implications of the study are highlighted and the need for further studies is recommended. [ABSTRACT FROM AUTHOR]

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The phosphorites of the Ameki Formation occur as nodules, pellets as well as primary phosphatic shales and siltstones. Geochemical analysis of the phosphate samples was carried out to determine its chemical composition as well as its depositional environment. The methodology applied include XRF, INAA, XRD and thin section petrography using Polarizing Microscope. The XRF result identified CaO-P2O5-F as the major mineral group, SiO2, Al2O3, Fe2O3, MgO and TiO2, which show minor occurrences and Cr, U, Pb, V, Cu, Zn, Se and Cd that occur in trace amounts. The nodules and pellets are of medium to high grade (25-34wt% P2O5) whereas the primary phosphatic shales and siltstones are of low to medium grade (4.5-22wt% P2O5). The phosphorites comprise mostly of francolites. The mean index of refraction estimated by Becke-line method using Standard Polarizing Microscope gave 1.634 and 1.636.XRD analysis yielded an average values of 9.243 (± 0.002) A° and 6.715 (± 0.002) A° for a and c crystallographic axes respectively with an axial ratio (c/a) of 0.726 for unit cell parameter, suggestive of low degree of carbonate substitution. An increase in P2O5content is found to be accompanied by increase in CaO, CO2 and F contents, but by a decrease in H2O, organic carbon, SiO2 and Fe contents indicative of amorphous solid phase of calcium phosphate. The phosphorite is interpreted to form under high biologic productive, shelf setting. High nutrient availability in the ancient sea is linked to upwelling along the West African Coastline during the Eocene. [ABSTRACT FROM AUTHOR]

Statistical analysis of surface radio refractive index and related atmospheric parameters over Ilorin (8°32II N, 4°34II E), North Central Nigeria, is presented. One minute interval measurement of temperature, pressure and relative humidity for a period of five years was obtained from the Baseline Surface Radiation Network (BSRN) of the University of Ilorin observatory. The diurnal and seasonal variations of these meteorological parameters especially in the tropics contribute to the analysis of refractivity variations and are needed for the design of efficient radio communication systems. Apart from the conventional deduction of low refractivity values in the dry season and high values in the wet season, the interrelationship of surface refractivity and related weather parameters were explored. The regression analysis carried out shows that mean monthly humidity and refractivity are well correlated with a correlation coefficient of 0.97 while the regression equation for predicting mean monthly refractivity N from the mean monthly relative humidity h is N = 0.881 h + 279. [ABSTRACT FROM AUTHOR]

The diurnal and seasonal variation of surface refractivity over Nigeria was studied using four years in-situ meteorological data from eight location over Nigeria. At all the stations studied, it was observed that the diurnal refractivity variation was caused majorly by the dry term in the rainy season and the wet term is the major cause of refractivity variation in dry season except Sokoto and Jos. In Sokoto the result was found to be opposite and it is attributed to the fact that in dry season the humidity is almost close to zero while in rainy season the pressure seems to be almost constant but the temperature fluctuates rapidly and consequently the humidity. The variation pattern in Jos is as observed because of the altitude (~ 1000m above sea level). At this altitude pressure variation seems to be insignificant. The result also show that the surface refractivity generally have higher value during rainy season than dry season at all location studied. The result also show that the value of surface refractivity increases from arid region in the north to the coastal area in south. The result also show that the diurnal refractivity variation is basically a function of local meteorology and while seasonal variation is caused follows the climatic condition. [ABSTRACT FROM AUTHOR]

Abstract: Anomalous propagation (Anaprop) of microwave radiation is known to be caused by several meteorological conditions. In this study, radio refractive index and modified refractivity gradient were computed using the results of measurements of atmospheric pressure, temperature and relative humidity made in Akure (7.15 ° N, 5.12 ° E), South Western Nigeria using Davis 6162 Wireless Vantage Pro2 weather stations (Integrated Sensor Suite, ISS) positioned at five different height levels beginning from the ground surface and at intervals of 50m from the ground to a height of 200m on a tower/mast owned by the Nigeria Television Authority (NTA) located at Iju in Akure north local government area of Ondo state but which is no longer being used. The study utilized one year of data measured between January and December 2008. From the results, the modified refractivity was calculated and found to increase with increasing altitude. The values were observed to be generally high during the rainy periods and generally low during the dry periods. The study also revealed that for microwave propagation in this geographic zone, the propagation condition is mostly super-refractive. [Copyright &y& Elsevier]

The optical properties of aerosols are investigated using multi-year analysis from the Ilorin AERONET site (8.320° N, 4.340° E) in Nigeria, in tropical West Africa. Characterization at five wavelengths (440, 550, 675, 870 and 1020 nm) were carried out to investigate the absorption and scattering tendencies of aerosol properties at multi-timescale. Results show large aerosol optical thickness (AOT) at 550 nm in a mixed aerosol load with 74% coarse mode dominance and 24% fine mode particles densely distributed in the dry-cold/Harmattan season (DJF) and sparsely distributed in the wet season (June–Oct). The volume size distribution (VSD) pattern shows higher variations and dominance for the coarse mode in the dry season than for the accumulation mode. The Ångström exponent (AE) α and τ 550 show regular variations, with seasonal averaged maximum α > 1 and τ 550 peak at ~ 1.0. Values of α > 1 were observed in wet seasons; ~1.1 (Aug), 1.04 (Sep). Averaged single scattering albedo (SSA) is confined to values between 0.83 and 0.97, with the highest values in October and lowest values in DJF due to biomass burning (BB) emissions mixed with transported desert dust that are composed of iron oxides (hematite) absorbing mineral. Seasonal ϖ 0 increases with increasing wavelength and absorption was found to be the highest at 440 nm, with a total absorption of 0.16. The asymmetry parameter g shows minor interannual variations. The highest value of >0.70 was found at the shortest wavelength (440 nm), and was found to decrease as wavelengths increased. The real part of the refractive index (RR) ranges between 1.17 and 1.44 depending on seasons, and the imaginary part of the refractive index (RI) shows higher absorption for dry season (0.009). • Optical properties of aerosols are investigated using ground-based data multi-year analysis in the tropic. • Large AOT is observed with 74% coarse mode aerosols as dominance and 24% fine mode particles. • Values of α > 1 are observed even in wet seasons, though dominant in DJF. • Total absorption of 0.16 is found across wavelengths studied and absorption is highest at 440 nm. • Volume size distribution pattern shows higher variations and dominance in the coarse mode in the dry season. [ABSTRACT FROM AUTHOR]