Current Journal of Applied Science and Technology

The selenium contents of three selected cereals (maize, millet and sorghum) and four selected legumes (soybeans, groundnuts, white and brown beans) grown and consumed in Central Nigeria was determined using hydride generation–atomic absorption spectrophotometry (HG–AAS). Results of the analysis showed that mean concentrations (µg/kg) of selenium in the cereals were 82.2 ± 27.7; 57.8 ± 12.2 and 38.6 ± 7.9 for maize, millet and sorghum, respectively.  Similarly, analytical results showed that among the legumes, brown beans contained the highest mean selenium contents (82.5 ± 18.9 µg/kg), followed by ground nuts (66.5 ± 15.4 µg/kg); the contents in soybeans (35.7 ± 9.3 µg/kg) and white beans (34.7 ± 7.2 µg/kg) were comparable. The mean values for selenium contents obtained in this work are generally higher than literature values for similar foodstuff, most of the values lie within the limit referred to as lower and safe upper reference nutrient intake. The differences could be determined due to the total selenium concentration and its bioavailability in the soils on which these crops are grown. The trend of selenium contents in the cereal and legume staples was as follows: maize > brown beans > groundnuts > millet > sorghum > soybeans > white beans.

The oil industry is experiencing a paradigm shift where the use of green chemicals is being encouraged in order to address environmental issues associated with the use of synthetic chemicals and also because of the fact that most of these synthetic polymers like hydrolysed polyacrylamide used to improve mobility ratio in Polymer flooding are imported chemicals. Thus, the need to source for other polymers that are viable and equally environmentally friendly.

Gum Arabic used in this analysis was obtained from the northern part of Nigeria. Different concentrations of Gum Arabic were analysed to study their rheology as well as the effect of salinity on them in order to determine their degree of resistance for this is a criterion in polymer flooding. However, the stability of Gum Arabic was further enhanced by the addition of Carboxymethyl Cellulose (CMC) at varying concentration to determine its effect on the solution viscosity. Based on the results, the effect of blending resulted in synergistic viscosity however, the stability of the solution with respect to the effect of salinity was affected.

The quality and stability of palm kernel oil (PKO) and cottonseed oil (CTSO) as affected by bleaching using modified oyster shell powder (OSP) and periwinkle shell powder (PSP) were evaluated by analysing their physicochemical properties. The two adsorbents potential was improved on by modification using 5 M HCl and H₂SO₄. The determinations of the parameters were carried out by titration, while the refractive index was determined using a refractometer. The results indicate that the saponification values (SV) of PKO and CTSO increase after bleaching. However, the result further shows that the peroxide values (PV) of bleached PKO using OSP and PSP modified with 5 M HCl decreased (17.49±0.01 and 20.04±0.08 respectively) and also the iodine values decreased (3.15±0.13 and 3.41±0.02 respectively).

The same decrease in PV and IV values is observed in PKO bleached using 5 M H₂SO₄. The values of PV for OSP and PSP are 4.99±0.005 and 12.77±0.77 respectively while the IV values for OSP and PSP are1.85±0.01 and 12.53±0.09 respectively. Also, 5 M HCl and H₂SO₄ modified OSP and PSP reduced the IV content in CTSO. (5 M HCl OSP and PSP are; 3.15±0.13 and 3.41±0.02 respectively while 5 M H₂SO₄ OSP and PSP values are; 3.33±0.04 and 3.13±0.06 respectively). The study revealed that the bleaching through the use of OSP and PSP influenced the components and properties of the PKO and CTSO, improved on their qualities and therefore, the adsorbents can serve as alternatives to the costly adsorbents available in the markets.

Optimal biomass production from microalgae using the NPK 20:20:20 medium; a relatively cheaper and locally available medium has been identified as an important factor in the large-scale algal biomass production. In this study, various concentrations (0.3-0.7 g/l) of NPK 20:20:20 were considered as the source of nitrogen in the growth medium for Chlorella sp. Four independent parameters in algae culture (nitrogen concentration, pH, inoculum size and duration of the experiment at varying ranges were studied for maximum biomass and chlorophyll production. Response Surface Methodology (RSM) procedure result that nitrogen concentration and pH level are the dominant factors affecting biomass and chlorophyll production. Maximum biomass was achieved at 0.5 g/l N and 8.5 pH value. Higher N (0.8 g/l) and lower N (0.3 g/l) had minimal effect on biomass and chlorophyll production. There was a linear relationship between chlorophyll and biomass production while the residual nitrogen had an inverse relationship with biomass production. Nitrogen concentration and pH were shown to be limiting factors under the conditions of the study. The inoculum size and duration of the experiment had a minimal effect on biomass production. 

Activated carbon obtained from ayous sawdust, Cucurbitaceae (egussi) peelings and the mixture of the two were studied for the adsorption of phenacetin. Characterisation of activated carbon by SEM and XRD analysis shows that the mixture of precursors combine the properties of activated carbon obtained separately. The well-knownbatch sorption models– Langmuir (one and two sites), Freudlich, Tempkin, Elovich, Langmuir-Freudlich, Redlich Peterson, Radke-Prausnitz, Fritz Shlunder)—were tested with experimental data for the adsorption of phenacetin to estimate adsorption equilibrium parameters—rate constantsand adsorption capacities. The model with the best fit was identified from extensive statistical analysis of the results of nonlinear regression of the experimental data. Comparison of the statistical errors in parameter estimation between linear and non-linear isotherm models shows that transformation of non-linear isotherm equations to linear forms implicitly alter their error structure. The much smaller size of the various error indicators —Determination Coefficient, R²; Sum of Square Errors, SSE; Chi Test, χ²; Average Relative Errors, ARE—, calculated for the case of non linearization when compared to linearization, indicate the greater accuracy in the application of non linearization. The Langmuir model (one site) gave the best fit and thus the values of adsorption capacity for each activated carbon were calculated from it. Kinetic models show that weak and strong interactions are involved in the adsorption process and that the controlling mechanism may not be limited to intra particle diffusion. The lower value of the boundary layer thickness in the case of activated carbon obtained from the mixture, justified the higher adsorbed quantity of this activated carbon compared to those of activated carbon from each precursor.

Objective of the current study was to optimize newly developed pant loading ramp to perform manual handling task. Pant loading ramp was 19 feet in length, having width of 2 feet, anti-slippery, easy to move due to provision of rotating wheels, adjustable at varying heights of the loading vehicle (between 2.5-5 feet) and reduces the loading time up to 30 minutes.  For this purpose experiments were conducted on a group of 20 experienced manual handlers in rice mills of Udham Singh Nagar district, Uttarakhand, India. The reliability and validity of the developed, loading ramp was assessed by using response surface methodology in terms of change in energy expenditure (EE), rate of perceived exertion (RPE), total cardiac cost of work (TCCW) and grip strength (GS). Therefore Response Surface Methodology (statistical tools to determine the significance of a factor over a response or collection of mathematical and statistical techniques for empirical model building) was applied to optimize the operating parameters of ramp such as load weight, height of ramp and time. As per Box Behenken design total 17 experiments were carried out each of which varied over three levels as load weight (40, 50 and 60 kg.), height of ramp (3, 4 and 5 feet), and time (3, 4 and 5 min.). ANOVA and coefficient of determination (R²) test were applied. In result it was observed that use of pant loading ramp was able to reduce Energy Expenditure (EE) of respondents’ from 14.55 kJ/min. to 11.41 kJ/min., Rate of Perceived Exertion (RPE) from 85.45 to 20%, Total Cardiac Cost of Work (TCCW) from 996.3 to 564.36 beats and Grip Strength (GS) from 47.45 to 3.30% with overall desirability of 0.84%. In comparison with traditional method it was also found to reduce Average Working heart Rate (AWHR) (14.55-11.41), Peak Energy Expenditure (PEE) (16-12), Rate of Perceived Exertion (RPE) (85.45-20), Grip Strength (GS) (47.45-3.30) and Total Cardiac Cost of Work (TCCW) (996.3-564.35). Relative advantages showed that more than 95% users were highly satisfied and found it advantageous.

Twenty diverse okra genotypes were evaluated to assess the genetic diversity based on quantitative morphological and qualitative biochemical traits in a randomized block design during 2015-16. On the basis of D² analysis, the 20 genotypes were clustered into five groups. Cluster I constituted the largest group (10 genotypes) followed by cluster II (7 genotypes). The cluster III, IV and V contains only 1 genotype in each cluster. Among phytochemical characters, carotenoids alone contribute highest percentage (39%) toward divergence, followed by chlorophyll a (31%) and anthocyanin (17%). The five principal components have accounted 81.19% of total variation and percent variation expected were 36.27% (PC1), 18.21% (PC2), 16.42% (PC3), 5.91% (PC4) and 4.38% (PC5), respectively. The PC1 has positive association with days to first flowering, followed by yield/plant, primary branches/plant, carotenoid and phenol contents. However, PC1 has negative association for fruits length, fruit diameter and ascorbic acid content. Therefore, the traits viz., days to first flowering, first flowering node and yield per plant should be given top priority in diverse parent selection for attempting high yielding along with important phytochemical properties in okra. Allocations of germplasm into different clusters were because of cumulative effect of number of characters.

Environmental contamination is one of the important issues that the world is facing today, it is always expanding and leading to the grave and harmful effect on the Earth. Nanoparticles have a diameter less than 100 nm exhibit new size-dependent properties compared with the bulk material. Engineered nanoparticles (ENPs) have unique characteristics in addition to the high surface area-to-volume ratio, which may increase their toxicity relative to bulk materials. Due to the high volume production of ENPs products such as carbon nanotubes, titanium dioxide, silver, zinc oxide environmental exposure to these compounds is very common. ENPs have their unique properties and applications in the areas of medicine, food& drink, construction, automotive, textiles, energy, electronics, environment etc. The present critical review is focused on the recent development of the applications of ENPs in the environmental remediation and their toxic effects.