The sonoluminescence (SL) from the collapse of a single gas bubble within a liquid can be produced repetitively using an acoustic resonator. An alternative technique using a water hammer tube, producing SL from bubbles of greater size, is described here. A sealed vertical tube partly filled with a liquid and a gas at low pressure is subjected to vertical vibrations. The oscillation of the pressure within the liquid column, due to inertial forces, excites cavitation bubbles to grow and collapse. Rotation is used to confine the bubbles to the axis of the tube. Bright SL emissions were observed in a number of liquids. Repetitive emission was produced from bubbles in condensed phosphoric acid. Bubbles of 0.4 mm ambient radius (containing 2x 10(14) xenon atoms) were excited by vibration at 35 Hz. Approximately 10(12) photons were emitted per collapse in the range 400-700 nm (over four orders of magnitude greater than the brightest SL reported previously), corresponding to a 1% efficiency of the conversion of mechanical energy into light.
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http://dx.doi.org/10.1103/PhysRevE.69.066317 | DOI Listing |
Sci Rep
December 2024
Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
In this study, 10 fish species, Jayan flounder (Pseudorhombus javanicus); Oriental sole (Eurgglossa arientalis); Oange-spotted grouper (Epinephelus coioides); Blacktip trevally (Caranx heberi); Towbar seabream (Acanthopagrus bifascia); Smalltooth emperor (Lethrinus microdon); Spangled emperio (Lethrinus nebulous); Sharptooth hammer croaker (Johnius vogleri); Bigeye croaker (Pennahia anea) and Redspine thread bream (Nemipterus nemurus), were examined in El-Jubail province, Saudi Arabia, Arabian Gulf region over three years from 2017 to 2020. The examined fish species showed muscular atrophy in a total percent of 1.1%, but with variable percentages of affections in each species.
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December 2024
Department of Mechanical Design, Faculty of Engineering, Helwan University, P.O. Box 11718, Mataria, Helmeiat-Elzaton, Cairo, Egypt.
Water hammer (WH) is a phenomenon characterized by the rapid opening or closing of valves or pumps in pipelines, resulting in a disruptive noise, intense vibrations, and potential damage to pipes, fittings, structures, and even human safety. While WH arresters are commonly employed to mitigate this issue in smaller plumbing systems, alternative solutions are required for larger applications like power plants. Researchers have proposed the utilization of pipe materials with a low modulus of elasticity in areas prone to WH events, as these materials possess the capability to absorb a significant portion of the resulting vibrations.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China. Electronic address:
Using renewable materials as primary components for constructing superhydrophobic coatings is an effective strategy for enhancing the environmental sustainability of anti-icing technologies. Alkali lignin, a by-product of the pulp and paper industry, was graft-modified with 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane to create a robust and multifunctional superhydrophobic coating for effective anti-icing. The results demonstrated that the industrial lignin-based coating achieved a contact angle of 162.
View Article and Find Full Text PDFPLoS One
December 2024
School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou, Henan, China.
Hydraulic transients in long-distance pressurized water pipelines significantly impact their normal operation. This study develops a one-dimensional mathematical model for pressurized water pipelines using the method of characteristics and incorporates water hammer equations for dual-pipeline systems. The model is validated with experimental data, and simulations are conducted under real engineering conditions, focusing on valve closure operations.
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September 2024
Center for Cognitive Interaction Technology, Universität Bielefeld, Bielefeld, North Rhine-Westphalia, Germany.
Especially if artificial intelligence (AI)-supported decisions affect the society, the fairness of such AI-based methodologies constitutes an important area of research. In this contribution, we investigate the applications of AI to the socioeconomically relevant infrastructure of water distribution systems (WDSs). We propose an appropriate definition of protected groups in WDSs and generalized definitions of group fairness, applicable even to multiple non-binary sensitive features, that provably coincide with existing definitions for a single binary sensitive feature.
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