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In this numerical work, heat transfer characteristics of humid air in a rectangular channel as solar air heater equipped with V‐shaped ribs has been investigated. The impacts of geometrical parameters of proposed ribs such as height, pitch, and angle relative to air flow direction, as well as relative humidity and Reynolds number of inlet humid air on thermal performance of proposed solar air heater have been evaluated. The numerical results have been achieved using commercial Computational Fluid Dynamics (CFD) code, ANSYS FLUENT 18.2, which works based on finite volume method. Outcomes shows that, over a wide range of operating conditions, utilizing ribs cause thermal boundary layer to separate and reattach, and eventually enhance heat transfer rate. Increasing the rib angle produces stronger secondary flows, leading to higher local velocities and greater heat transfer rate. Moreover, increasing the relative humidity of inlet air from 0% to 50% leads to improve heat transfer by up to 6%. As Reynolds number increases from 4000 to 12,000, average Nusselt number rises by 7.3% and 31.4% for rib pitches of 6 and 16 mm, respectively. The results demonstrate how thermal performance of a solar air heater can be improved by utilizing V‐shaped ribs. [ABSTRACT FROM AUTHOR]

One of the greatest challenges in recent years is providing enough food to feed the increasing world population, with limited freshwater resources. However, effective fertiliser management also has a fundamental role to improve yield quality and quantity. Organic fertiliser not only supplements nutrients but also improves physicochemical and biological soil properties. A 2‐year field experiment was conducted to examine the influence of urea and vermicompost fertiliser on oil phytochemical properties of peppermint pH, soil cation exchange capacity (CEC) and organic carbon of experimental site under three irrigation regimes in 2018 and 2019. The experiments had three water deficit regimes (no stress, moderate, and severe drought stress) as a main plot. The subplot division consisted of six fertiliser treatments: unfertilised (control); 140 kg urea ha−1; 105 kg urea ha−1 + 3.3 ton vermicompost ha−1; 70 kg urea ha−1 + 6.6 ton vermicompost ha−1; 35 kg urea ha−1 + 10 ton vermicompost ha−1; and 13.5 ton vermicompost ha−1. The maximum leaf area index (4.29) and dry matter weight (3,803 kg ha−1) were observed in control irrigation, while the highest essential oil content (0.97%) could be seen under mild water deficit stress. Additionally, the highest organic carbon and CEC were obtained under well‐watered conditions at 1.20% and 6.41 (meq 100 g soil−1), respectively. Dry matter weight and essential oil content increased considerably in response to increasing vermicompost in fertiliser treatments, and the highest content of these traits were observed in 2019 and with 13.5 ton vermicompost ha−1. The menthol content increases in response to deficit irrigation and integrated fertiliser. These data indicate that mild drought stress can increase the synthesis of medical compounds and vermicomposting can alleviate the impact of drought by conserving soil moisture as an acclimation mechanism to improve nutrient uptake and avoid yield losses. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, we employ the Reduced Surface Field technique in metal semiconductor field effect transistors (MESFETs) by a P-type region above the active layer near gate (PR-MESFET). Electric field distribution can be made more uniform by a new depletion region in the active layer of the proposed structure that is created by a P-type region. Therefore, the electric field peak at the gate edge decreases, and the breakdown voltage increases. On the basis of our simulation results, the breakdown voltage increases as compared with the conventional bulk 4H-SiC MESFET (CB-MESFET) and the spacer bulk 4H-SiC MESFET (SB-MESFET). Detailed numerical simulations demonstrate that for proposed structure due to decrease in parasitic gate-to-drain capacitor, maximum oscillation frequency increases with respect to SB-MESFET. Our simulation results show that output current slightly decreases in comparison with CB-MESFET. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]