Laminar Convection in a Uniformly Heated Vertical Porous Channel Revisited
Basant K. Jha,
Michael O. Oni
Issue:
Volume 2, Issue 3, June 2017
Pages:
28-32
Received:
2 March 2017
Accepted:
25 April 2017
Published:
5 July 2017
Abstract: This work revisited the mixed convection flow formation in a uniformly heated vertical porous channel filled with porous material as discussed by Chandrasekhara and Nayrayanan [11]. Using perturbation method as well as numerical solution, Chandrasekhara and Nayrayanan [11] discussed the behavior of the fluid as well as rate of heat transfer. This methods are known not to be exact solution. In this work, we derived an exact solution using D’Alembert’s method and corrected some results obtained in [11]. To justify the accuracy of the present method, we used the implicit finite difference method (IFDM). Result shows that D’Alembert’s method is more efficient, effective and thus a promising tool for finding exact solution for coupled equations.
Abstract: This work revisited the mixed convection flow formation in a uniformly heated vertical porous channel filled with porous material as discussed by Chandrasekhara and Nayrayanan [11]. Using perturbation method as well as numerical solution, Chandrasekhara and Nayrayanan [11] discussed the behavior of the fluid as well as rate of heat transfer. This m...
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Effect of Pre-treatment of Barley Grain on Germination and Seedling Growth Under Drought Stress
Mahmoud Abdel-Moneim Khafagy,
Zain Al-Abidin Abdul Hamid Mohamed,
Saad Farouk,
Hanan Khaleel Amrajaa
Issue:
Volume 2, Issue 3, June 2017
Pages:
33-42
Received:
7 May 2017
Accepted:
25 May 2017
Published:
6 July 2017
Abstract: Seed priming is currently a wide used commercial process that accelerates the germination rate and improves seedling uniformity in several crops. A laboratory study was conducted to evaluate the effect of grain priming treatments on barley grain germination and seedling growth under drought stress imposed by PEG-6000. The experiment was performed employing a factorial completely randomized block design with four levels of drought stress (0,10,20 and 30% PEG6000) and 14 priming treatments (dry, hydropriming, 5, 10, 15% PEG-6000; 500, 1000, 1500 mg/l KNO3; 25, 50, 75 mg/l thiamin; 50, 100, 150 mg/l sodium metasilicate) with five replications for each treatment. Germination percentage, germination index, energy of germination, mean germination time, seedling vigor, seedling length, 10 seedling fresh and dry weights were measured below the experimental conditions. Variance analysis results (ANOVA) showed extremely significant (p<0.05) variations between treatments in all traits. It had been discovered that increasing PEG concentrations up to 30% significantly decrease germination criteria and seedling growth traits and that priming treatments in most cases significantly increased all germination and seedling parameter. The most effective in this regard was 1000 mg/l potassium nitrate as compared with untreated control treatment. Priming treatments in most cases mitigates PEG effects as a major increase, particularly with 1000 mg/l potassium nitrate. It is concluded that potassium nitrate at 1000 mg/l is helpful to enhance drought tolerance of barley grain germination and seedling growth.
Abstract: Seed priming is currently a wide used commercial process that accelerates the germination rate and improves seedling uniformity in several crops. A laboratory study was conducted to evaluate the effect of grain priming treatments on barley grain germination and seedling growth under drought stress imposed by PEG-6000. The experiment was performed e...
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