Thermodynamic analysis of a variable viscosity reactive hydromagnetic couette flow within parallel plates

This investigation is to consider the impact of a temperature-dependent variable viscosity of a reactive hydromagnetic Couette fluid flowing within parallel plates. The variable property of the fluid viscosity is thought to be an exponential relation of temperature under the impact of magnetic strength. The differential equations controlling the smooth movement of fluid and energy transfer are modeled and solved by using the series solution of modified Adomian decomposition technique (mADM). The outcomes are shown in tables and graphs for different estimations of thermophysical properties present in the flow regime together with the rate of entropy generation and irreversibility distribution outcome. Keywords: Reactive fluids, Couette Flow, variable viscosity, hydromagnetic and modified Adomian decomposition method (mADM)

Viscous Dissipation Effect On The MHD Flow Of A Third Grade Fluid Down: an Inclined Plane With Ohmic Heating

The thin film flow and heat transfer problem of a third grade fluid down an inclined plane is investigated. The fluid is incompressible and electrically conducting in the presence of a uniform magnetic field. The non-linear equation governing the flow and heat transfer are solved for the velocity and temperature profile by employing the regular perturbation technique as well as homotopy perturbation method and the results are presented graphically. The effect of magnetic parameter and Brinkman number are analyzed for velocity and temperature profile. It is noticed that increase in magnetic parameter reduced the velocity of the fluid and increases the temperature profile. Also, increase in Brinkman number increases the temperature profile. Keywords: Third grade fluid, Brinkman number, Perturbation method, Homotopy perturbation method, Magnetohydrodynamics

MHD Flow of A Third Grade Fluid with Heat Transfer And Slip Boundary Condition Down An Inclined Plane

In this work, we consider the combine effects of slip boundary ohmic heating on MHD flow of a third grade fluid down an inclined plane. The couple non-linear ordinary differential equations arising from the model were solved using both the regular and homotopy perturbation. Effects of the various thermo physical parameters are studied and depicted graphically. Keywords: Slip boundary, MHD, Third grade fluid, Ohmic heating, inclined plane

A Comparison of the Semi Analytical and Numerical Method in Solving the Problem of Magnetohydrodynamics Flow of a Third Grade Fluid between Two Parallel Plates

The main purpose of this study is to compare a semi-analytical method and numerical method namely the homotopy perturbation method (HPM) and finite difference method (FDM) respectively. These methods were employed for solving the nonlinear problem of the magnetohydrodynamic (MHD) couette flow of third-grade fluid between the two parallel plates. The comparison was made between a solution of HPM and FDM against a solution obtained from regular perturbation and the results are tabulated. From a computational viewpoint, it is revealed that the HPM is more reliable and efficient than FDM. Also, the results show that the FDM requires slightly more computational effort than the HPM, although the HPM yields more accurate results than the FDM. &nbsp

Mn(II), Co(II), Ni(II), and Cu(II) complexes of amino acid derived Schiff base ligand: Synthesis, characterization and in-vitro antibacterial investigations

Four complexes of Mn(II), Co(II), Ni(II) and Cu(II) with Schiff base ligand (H3L) derived from 2-amino-3-methylbutanoic acid and acetylacetonate were synthesized. All complexes were characterized by elemental analysis, Fourier-transform infrared spectroscopy and electronic spectroscopy. The results confirmed the coordination of the ligand to metals in tridentate fashion via the hydroxyl oxygen, the azomethine nitrogen and the enolic acetylacetonate oxygen. Antimicrobial activities were established for all complexes, free ligand and ciprofloxacin for comparison. Both the ligand and its metal complexes were active against Gram-positive and negative bacterial strains. The Cu(II) complex, showed highest antibacterial activity among the complexes screened. Other complexes displayed considerable antibacterial activity. Octahedral geometry was proposed for the metal(II) complexes with the Schiff base.                     KEY WORDS: Schiff base, Amino acid, Metal Complexes, Antibacterial agents   Bull. Chem. Soc. Ethiop. 2021, 35(1), 97-106. DOI: https://dx.doi.org/10.4314/bcse.v35i1.

Influence of Different Fertilizer Types on the Growth and Yield of Two Varieties Cucumber (Cucumis melo)

The growth, yield and nutritional quality of Poinsett and Marketmore varieties of cucumber in response to compost and NPK fertilizer application were evaluated at the Teaching and Research Farm of the Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria. The six fertilizer combinations are T1 (0 kg N), T2 (100% NPK, 600 kg NPK 15:15:15), T3 (100% Tithonia compost (TC), 5 tons/ha), T4 (75% NPK + 25% TC), T5 (50% NPK + 50% TC) and T6 (25% NPK+ 75% TC). The treatments were arranged as 6 × 2 factorial scheme in Randomised Complete Block Design with three replicates. Data were collected on growth parameters, fruit yield, calcium content and iron content. Data collected were subjected to analysis of variance and difference among treatments means was computed using Least Significant Difference at 0.05 probability level. The results revealed that at the point of maximum growth Poinsett cucumber variety produced significant longer vine (173.78cm); higher number of leaves (23.56) and more robust stem girth (3.01 cm) than the other variety. At 8 weeks after sowing (WAS) the longest vine length (216.67cm) and number of leaves (29.33) were obtained from cucumber plants treated with 5 tons/ha. Varietal effect was not significant (p≤0.05) on cucumber fruit yield and firmness. The vine length, fruit girth, stem girth, number of leaves were significantly influenced by the application of 5 tons/ha. At 8 WAS, the longest vine 216.67cm and highest number of leaves (27.33) were recorded from 5 tons/ha, while the widest stem girth (2.10cm) was gotten from 50% NPK + 50% TC treated cucumber. Fruit yield was significantly improved by the application of different combination of fertilizer. Plant that received fertilizer had significant better fruit yield compared with non-fertilized one. However, the use of 50% NPK + 50% TC gave the highest fruit yield. The study concluded that combine application of 300 kg NPK + 2.5 ton/ha TC would be sufficient for production of the two varieties tried in this study. Keywords: Cucumber; farmyard manure; inorganic fertilizer; growth; yield. DOI: 10.7176/JBAH/9-14-03 Publication date:July 31st 201

Effect of NPK Fertilizer and Transplant Age On Growth, Fruit Yield And Nutritional Content Of Solanum Melongena South Western Nigeria

Good and sustainable agronomic practices are needed in vegetable production to maintain high crop yield.  As part of efforts to achieve this, two field experiments were carried out between 2008 and 2010 to evaluate the combined effects of age of transplant and NPK fertilizer on the growth, fruit yield and quality of Solanum melongena var.’ long purple’. Four levels of NPK fertilizer (0, 200, 300 and 400 kg NPK/ha) and three ages of transplanting (5, 6 and 7 weeks after sowing) in 12 factorial combinations were the treatments. These were laid out in randomized complete block design replicated thrice. Data collected were subjected to analysis of variance and significant means compared using least significant difference (LSD) at 5% probability level. All the growth parameters and fruit attributes assessed increased with increasing levels of NPK. Application of 300 kg NPK/ha produced the best growth while plants that received 200 kg NPK /ha and non-fertilized plants had least performance. The fruit and seed attributes such as fruit length and girth, number of fruits/plant,  number of seeds/fruits, seed weight, and fruit yield were all significantly influenced by the fertilizer levels. The number of fruits/plant ranges from 4.3 in non- fertilized plants to 8.2 in 300kg NPK /ha treatment. There was no significant difference in fruit yield produced by 300 (26.88 t /ha) and 400 kg (28.78 t /ha) NPK /ha treatments. Transplanting of seedling at 6 weeks after sowing (WAS) produced significantly better plant growth, fruit attributes and fruit yield compared to plants transplanted at 5 and 7 WAS. It can be concluded that application of 300 kg NPK /ha in combination with transplanting of seedlings at 6 weeks are good agronomic practices that could ensure optimum performance of Solanum melongena. Key words: Solanum melongena, NPK fertilizer, age of transplant, growth, fruit yield                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

Toxicity of powder and extracts of Zanthoxylum zanthoxyloides Lam (Rutaceae) root bark from Nigeria to three storage beetles

The root of Zanthoxylum zanthoxyloides Lam is used as antibacterial toothbrush in southwestern Nigeria. The root bark was therefore screened as powder, aqueous and ethanolic extracts for toxicity to adult Callosobruchus maculatus F. (Coleoptera: Bruchidae), Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the effects of the test extracts on oviposition and progeny development of C. maculatus in laboratory tests. A small scale field trial was also carried out to test the efficacy of test powder as a protectant of cowpea, Vigna unguiculata (L.) Walpers and maize, Zea mays L. grains against insect infestation. Results of the acute toxicity tests showed that all the formulations were toxic to the insects. The 48 h median lethal concentration (LC50) values obtained for the test powder against C. maculatus, S. zeamais and T. castaneum are 0.05 g kg-1, 0.01g kg-1 and 0.04 g kg-1, respectively. For the aqueous extracts the LC50 values are 0.83 g L-1, 0.34 g L-1 and 0.38 g L-1 against C. maculatus, S. zeamais and T. castaneum, respectively while the values are 0.02 g L-1, 0.04 g L-1 and 0.09 g L-1, respectively for ethanolic extract, indicating higher toxicity against the test insects relative to the water-based extract. The ethanolic extract demonstrated residual property, the toxicity to C. maculatus remaining fairly constant over a total post-treatment time of 336 h. Cowpea grain treatment with test plant ethanolic extract resulted in reduction of the number of eggs laid from 93.30 ± 3.46 in the control to 21.00 ± 4.57 in grain treated with 0.10 g L-1 extract without significant difference in the number of adult emergence from the treated grains. Field trials showed that cowpea and maize grains treated with test plant powder respectively were protected from insect infestation for 180 d. These results demonstrate the potentials of Z. zanthoxyloides for protecting cowpea and maize grains against storage insects.Keywords: Zanthoxylum zanthoxyloides, Callosobruchus maculatus, Sitophilus zeamais, Tribolium castaneum, Toxicit