Characterization of acoustic emissions resulting from particle collision with a stationary bubble

2013 ◽  
Vol 133 (5) ◽  
pp. 2523-2527
Author(s):  
Wen Zhang ◽  
Steven J. Spencer ◽  
Peter Coghill
Keyword(s):  
Acoustic Emissions ◽  
Particle Collision ◽  
Stationary Bubble

scholarly journals A Minimal Metric for the Characterization of Acoustic Noise Emitted by Underwater Vehicles

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6644
Author(s):  
Giacomo Picardi ◽  
Clara Borrelli ◽  
Augusto Sarti ◽  
Giovanni Chimienti ◽  
Marcello Calisti
Keyword(s):  
Acoustic Noise ◽  
Acoustic Emissions ◽  
Remotely Operated Vehicles ◽  
Underwater Robots ◽  
Acoustic Disturbance ◽  
Marine Fauna ◽  
Acoustic Data

Underwater robots emit sound during operations which can deteriorate the quality of acoustic data recorded by on-board sensors or disturb marine fauna during in vivo observations. Notwithstanding this, there have only been a few attempts at characterizing the acoustic emissions of underwater robots in the literature, and the datasheets of commercially available devices do not report information on this topic. This work has a twofold goal. First, we identified a setup consisting of a camera directly mounted on the robot structure to acquire the acoustic data and two indicators (i.e., spectral roll-off point and noise introduced to the environment) to provide a simple and intuitive characterization of the acoustic emissions of underwater robots carrying out specific maneuvers in specific environments. Second, we performed the proposed analysis on three underwater robots belonging to the classes of remotely operated vehicles and underwater legged robots. Our results showed how the legged device produced a clearly different signature compared to remotely operated vehicles which can be an advantage in operations that require low acoustic disturbance. Finally, we argue that the proposed indicators, obtained through a standardized procedure, may be a useful addition to datasheets of existing underwater robots.

scholarly journals Damage Characterization of Bio and Green Polyethylene–Birch Composites under Creep and Cyclic Testing with Multivariable Acoustic Emissions

Materials ◽  
2015 ◽  
Vol 8 (11) ◽  
pp. 7322-7341 ◽  
Author(s):  
Alencar Bravo ◽  
Lotfi Toubal ◽  
Demagna Koffi ◽  
Fouad Erchiqui
Keyword(s):  
Acoustic Emissions ◽  
Cyclic Testing ◽  
Damage Characterization

scholarly journals Extensive characterization of seismic laws in acoustic emissions of crumpled plastic sheets

2016 ◽  
Vol 114 (5) ◽  
pp. 59002 ◽  
Author(s):  
Leandro S. Costa ◽  
Ervin K. Lenzi ◽  
Renio S. Mendes ◽  
Haroldo V. Ribeiro
Keyword(s):  
Acoustic Emissions

Effect of solid hold-up on nitrite accumulation in a biofilm reactor - molecular characterization of nitrifying communities

2004 ◽  
Vol 49 (11-12) ◽  
pp. 123-130 ◽  
Author(s):  
N. Bernet ◽  
O. Sanchez ◽  
P. Dabert ◽  
A. Olaïzola ◽  
J.J. Godon ◽  
...  
Keyword(s):  
Biofilm Reactor ◽  
Point Of View ◽  
Particle Collision ◽  
Ammonium Concentration ◽  
Nitrite Accumulation ◽  
Ammonium Oxidation ◽  
Biofilm Growth ◽  
Bed Height ◽  
Nitrite Production

Biological ammonium oxidation was carried out in two inverse turbulent bed reactors fed with synthetic mineral wastewater containing a high ammonium concentration (100 mg N-NH4+/L). Both reactors were started-up and operated in the same conditions except for the solid carrier concentration: the solid hold-up ratios applied, defined as the ratios of static to expanded bed height, were 0.1 and 0.3 in reactors R10 and R30 respectively. These two solid hold-up ratios generate different particle-to-particle collision frequencies and, therefore, detachment forces. The influence of solid hold-up on biofilm growth and nitrifying performance was studied from a macroscopic (i.e. nitrate and/or nitrite production) and microbiological point of view. After 60 days of operation, both reactors contained the same amount of biomass. However, R10 produced only nitrate while nitrite accumulated in R30. A comparison of microbial populations in the reactors showed that R10 contained both ammonium and nitrite oxidizing populations such as Nitrosomonas and Nitrospira, whereas in R30, ammonium oxidizing populations were much greater than those of nitrite oxidizers. The major ammonium-oxidizing organism was not the same in both reactors.

Rapid characterization of arsenic adsorption on single magnetite nanoparticles by collisions at microelectrodes

2020 ◽  
Vol 7 (7) ◽  
pp. 1999-2009
Author(s):  
Farideh Hosseini Narouei ◽  
Daniel Andreescu ◽  
Silvana Andreescu
Keyword(s):  
Magnetite Nanoparticles ◽  
Single Particle ◽  
Redox Properties ◽  
Particle Collision ◽  
Inexpensive Method ◽  
Arsenic Adsorption ◽  
Rapid Characterization

A rapid and inexpensive method to analyze redox properties of magnetite nanoparticles and quantify arsenic adsorption by single particle collision electrochemistry.

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