Restoration of degraded lands by adoption of recommended conservation management practices can rehabilitate watersheds and lead to improving soil and water quality. The objective was to evaluate the effects of grass buffers (GBs), biomass crops (BCs), grass waterways (GWWs), agroforestry buffers (ABs), landscape positions, and distance from tree base for AB treatment on soil quality compared with row crop (RC) (corn [Zea mays L.]–soybean [Glycine max (L.) Merr.] rotation) on claypan soils. Soil samples were taken from 10‐cm‐depth increments from the soil surface to 30 cm for GB, BC, GWW, and RC with three replicates. Soil samples were collected from summit, backslope, and footslope landscape positions. Samples were taken at 50‐ and 150‐cm distances from the tree base. β‐Glucosidase, β‐glucosaminidase, dehydrogenase, fluorescein diacetate hydrolase (FDA), soil organic carbon (SOC), total nitrogen (TN), active carbon (AC), and water‐stable aggregates (WSA) were measured. Results showed that β‐glucosidase, β‐glucosaminidase, dehydrogenase, FDA, AC, WSA, and TN values were significantly greater (P < 0.01) for the GB, BC, GWW, and AB treatments than for the RC treatment. The first depth (0–10 cm) revealed the highest values for all soil quality parameters relative to second and third depths. The footslope landscape had the highest parameter values compared with summit and backslope positions. The 50‐cm distance of AB treatment had higher values than the 150‐cm distance for all measured parameters. Results showed that perennial vegetation practices enhanced soil quality by improving soil microbial activity and SOC.
Core Ideas
Permanent vegetative management (trees and grasses) enhanced soil quality.
Perennial practices improved microbial activity and increased soil organic carbon.
Perennial vegetative practices have agricultural and environmental significance.
Establishing perennial practices is an effective approach to enhance soil quality.
In solar-thermal adsorption/desorption processes, it is not always possible to preserve equal operating times for the adsorption/desorption modes due to the fluctuating supply nature of the source which largely affects the system’s operating conditions. This paper seeks to examine the impact of adopting unequal adsorption/desorption times on the entire cooling performance of solar adsorption systems. A cooling system with silica gel–water as adsorbent-adsorbate pair has been built and tested under the climatic condition of Iraq. A mathematical model has been established to predict the system performance, and the results are successfully validated via the experimental findings. The results show that, the system can be operational
The necessary optimality conditions with Lagrange multipliers are studied and derived for a new class that includes the system of Caputo–Katugampola fractional derivatives to the optimal control problems with considering the end time free. The formula for the integral by parts has been proven for the left Caputo–Katugampola fractional derivative that contributes to the finding and deriving the necessary optimality conditions. Also, three special cases are obtained, including the study of the necessary optimality conditions when both the final time and the final state are fixed. According to convexity assumptions prove that necessary optimality conditions are sufficient optimality conditions.
Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared w
In this paper, chip and powder copper are used as reinforcing phase in polyester matrix to form composites. Mechanical properties such as flexural strength and impact test of polymer reinforcement copper (powder and chip) were done, the maximum flexural strength for the polymer reinforcement with copper (powder and chip) are (85.13 Mpa) and (50.08 Mpa) respectively was obtained, while the maximum observation energy of the impact test for the polymer reinforcement with copper (powder and chip) are (0.85 J) and (0.4 J) respectively
Linear motor offers several features in many applications that require linear motion. Nevertheless, the presence of cogging force can deteriorate the thrust of a permanent magnet linear motor. Using several methodologies, a design of synchronous single sided linear iron-core motor was proposed. According to exact formulas with surface-mounted magnets and concentrated winding specification, which are relying on geometrical parameters. Two-dimensional performance analysis of the designed model and its multi-objective optimization were accomplished as a method to reduce the motor cogging force using MAXWELL ANSYS. The optimum model design results showed that the maximum force ripple was approximatrly reduced by 81.24%compared to the origina
