For undersea activities, underwater vehicles usually carry optical imaging systems for recording. The captured images and videos frequently suffer from two displeasing problems: First, color distortion; and second, poor visibility. This is mainly because that the light is exponentially attenuated while penetrating through water and the strength of attenuation is color dependent. This paper develops an effective single underwater image restoration framework based on the depth estimation and the transmission compensation. To address the consequences of scattering and absorption, our restoration scheme consists of five major phases: 1) background light estimation; 2) submerged dark channel prior; 3) transmission refinement and radiance recovery; 4) point spread function deconvolution; and 5) transmission and color compensation. A wide variety of underwater images with various scenarios were exploited to assess the restoration performance of the proposed algorithm. Various evaluation metrics were employed to analyze the experimental results. It was suggested that this new restoration algorithm outperformed many state-of-the-art methods both qualitatively and quantitatively. In addition, potential applications regarding autopilot and three-dimensional visualization were demonstrated. We believe that our underwater image restoration technique is promising in many undersea activities that require high-quality images.

(AlCrNbSiTiV)N high-entropy alloy (HEA) nitride coatings have been grown on cermet tools inserts and glass substrates. Using reactive direct current magnetron sputtering with an equimolar AlCrNbSiTiV HEA target and Ar plasma and N₂ reactive gases. In this study, the influence of (AlCrNbSiTiV)N coatings varied substrate temperature (room, 100, 200, 300, 400°C), on the structure, mechanical properties and cutting performance of the cermet cutting tools was investigated in dry machining of a SCM440 steel. The (AlCrNbSiTiV)N films coated was homogeneous, very compact and shows good adhesion strength (classified as HF1). The TEM image results indicate that the (AlCrNbSiTiV)N films are simple face-centre-cubic structures. As the substrate temperature increases, the films hardness increases, reaching the maximum value of 2493 HV at 100°C, and then decreases with further increase in the substrate temperature. The cutting performance improves when coated tools are used. The machined surface with the coated tool using a substrate temperature 100°C deposition parameters, show less surface defects and the tool flank wear is reduced.

The planning and design of an outlet operation by releasing a turbid density current from a reservoir requires accurate prediction of outflow concentration for sluicing sediment through outlet structures. This study investigates outflow concentration and venting efficiency through reservoir outlets in a reservoir sluicing operation related to turbid density current. A 3D numerical model is employed to simulate a venting operation for a turbid density current in typhoon-induced flood events. A simple and efficient formula derived from theoretical analysis with experimental data is proposed for estimating outflow concentration and venting efficiency. By adopting the proposed formula to avoid time-consuming calculation using the 3D numerical model, the estimated outflow concentration and venting efficiency through reservoir outlets have shown good agreement with the measured and simulated results in typhoon flood events. This demonstrates that the formula provides an efficient approach for engineering practice in real-time reservoir venting operations.

This study mixed acetylacetone (Acac, 1, 2, and 3 mL) and graphene powder (GP, 0 wt.%, 0.001 wt.%, 0.003 wt.% and 0.005 wt.%) with TiO₂ mesoporous (TiO₂ powders: 20 g and particle size ~30 nm) to enhance the optoelectronic performances of dye sensitized solar cells (DSSC). Sponge-like structure TiO₂ mesoporous layers is a requirement for obtaining high efficiency DSSC, which ia synthesized by spin-coating techniques. The dense TiO₂ blocking layer (using peroxo-titanium complex) has a uniform, dense structure and completely adheres to the substrates to avoid charge recombination. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses of the TiO₂ films display the anatase type phase with preferred orientation along the (101) direction. After being ball milled, the TiO₂ mesoporous particle size almost remains unchanged. For mixing the Acac with TiO₂, the Raman intensity relatively increased, and the band gap energy (Eg) value decreased from 3.223 eV (for pure TiO₂) to 3.076 eV (for 2 mL Acac). Raman spectroscopy is used to evaluate the GP elements. It can be seen the intensity ratio (I_D/I_G) and (I_2D/I_G) was enhanced when the GP concentration increased. Using mixed Acac 2 mL and GP 0.003 wt.% with a TiO₂ mesoporous, led to increases in the open circuit voltage (V_OC), short circuit current density (J_SC) and fill factor (FF). If a fluorine-doped tin oxide is used instead of an indium tin oxide glass substrate, the photovoltaic efficiency of DSSC increases from 5.45% to 7.24%.