Coaxial rotors are utilized in multirotor aerial vehicles for the added thrust compared to independent while keeping similar area footprints; however, performance losses should be considered. This experimental study analyzes effects of varying motor duty cycle and propeller pitch values motor-propeller systems with two four coaxial rotors. The results demonstrate that a two-rotor system, lessen...

Gravel beaches are prevalent natural features on many coastlines and play a vital role in shore protection, often inspiring protection structures (Bayle et al., 2020) nature-based solutions. Dynamic revetments constructed features, designed to mimic gravel beaches, dissipating wave energy preventing or limiting erosion. Compared sand dissipate incident dampen backwash intensity by percolating t...

under investigation. The early models to solve Navier-Stokes equation for a laminar flow in porous tube were proposed in Berman [1] and Yuan [2] and extended by Bernales [3]. Berman [1] presented a solution to the two-dimensional model in laminar flow in channels with uniform wall suction. This study was extended to cylindrical coordinates to investigate suction as well as injection in flow alo...

This study aims to evaluate the application of ultrafiltration technology for separation particles and oil droplets recovery ammonia from hydrothermal liquefaction (HTL) wastewater. Real HTL wastewater municipal sewage sludge was used in this study. Experiments were carried out using a submerged polyethersulfone membrane with molecular weight cutoff 100 kDa combination air stripping addition ac...

Polymer-enhanced ultrafiltration has gained increasing attention as a selective separation process to remove small solutes, such metal ions, from water or wastewater. Hexavalent chromium Cr(VI) is one of the ions in wastewater that received considerable because its toxicity. Chitosan was used this study polymer bind enhance removal by ultrafiltration. The effects chitosan-to-Cr(VI) ratio on rej...