This report presents a brief resume of the underwater visibility problem and explains the circular polarization approach for improving contrast. Experimental apparatus was set up at the Morris Dam facility of the U.S. Naval Ordnance Test Station, Pasadena Annex, and tests were conducted both with and without polarization. Results show that use of the polarization technique increased the visibility range in turbid water by at least a factor of two.
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http://dx.doi.org/10.1364/AO.6.000741 | DOI Listing |
Langmuir
January 2025
College of Light Industry and Materials, Chengdu Textile College, Chengdu, Sichuan 610039, China.
The treatment of oily wastewater and oil/water mixtures has received more and more attention. In this study, a Zn-MOF (ZIF-8) decorated polyimide (PI) nanofiber membrane with triple self-cleaning performance was constructed, and the decoration of ZIF-8 on the PI membrane improved the hydrophilicity of the composite membrane, which further enhanced the underwater oil resistance, and the mechanical properties of the membranes improved significantly with the increase of in situ growth time. In addition, the inherent photocatalytic and antibacterial properties of ZIF-8 endowed the membranes with fantastic performance.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin 150040, China.
In this paper, InSe nanosheets were synthesized by a ball milling method, and photoelectrochemical-type photodetectors (PEC PDs) based on the ball milling InSe (M-InSe) were fabricated using simulated seawater as the electrolyte. M-InSe nanosheets show good absorption in the visible region of 450-600 nm. The M-InSe PEC PDs display a good self-powered photoresponse under 525 nm irradiation, including a high responsivity of 0.
View Article and Find Full Text PDFSensors (Basel)
November 2024
College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China.
Underwater simultaneous localization and mapping (SLAM) has significant challenges due to the complexities of underwater environments, marked by limited visibility, variable conditions, and restricted global positioning system (GPS) availability. This study provides a comprehensive analysis of sensor fusion techniques in underwater SLAM, highlighting the amalgamation of proprioceptive and exteroceptive sensors to improve UUV navigational accuracy and system resilience. Essential sensor applications, including inertial measurement units (IMUs), Doppler velocity logs (DVLs), cameras, sonar, and LiDAR (light detection and ranging), are examined for their contributions to navigation and perception.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin 150040, China.
Photoelectrochemical photodetectors (PEC PDs) are promising in underwater optoelectronic devices because of their low cost, good sensitivity, and self-powered characteristics. However, achieving high-performance omnidirectional visible PEC PDs using seawater as the electrolyte is still challenging, hindering their practical application. This work successfully synthesized CuO nanobelt arrays (NAs) on a linear copper wire via a low-temperature solution method with an annealing process.
View Article and Find Full Text PDFPeerJ Comput Sci
November 2024
School of Computer Science and Engineering, Vellore Institute of Technology, Chennai, Tamil Nadu, India.
Underwater images hold immense value for various fields, including marine biology research, underwater infrastructure inspection, and exploration activities. However, capturing high-quality images underwater proves challenging due to light absorption and scattering leading to color distortion, blue green hues. Additionally, these phenomena decrease contrast and visibility, hindering the ability to extract valuable information.
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