A Sheet of Air Bubbles as an Acoustic Screen for Underwater Noise

1948 ◽  
Vol 20 (2) ◽  
pp. 143-145 ◽  
Author(s):  
Donald P. Loye ◽  
Wm. Fred Arndt
Keyword(s):  
Air Bubbles ◽  
Underwater Noise

scholarly journals Air bubbles play a role in shear thinning of non-colloidal suspensions

2021 ◽  
Vol 33 (1) ◽  
pp. 011702
Author(s):  
Yuan Lin ◽  
Ying Wang ◽  
Zixin Weng ◽  
Dingyi Pan ◽  
Jiawang Chen
Keyword(s):  
Colloidal Suspensions ◽  
Shear Thinning ◽  
Air Bubbles

scholarly journals Measurement of Underwater Acoustic Energy Radiated by Single Raindrops

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2687
Author(s):  
Shu Liu ◽  
Qi Li ◽  
Dajing Shang ◽  
Rui Tang ◽  
Qingming Zhang
Keyword(s):  
Ambient Noise ◽  
Sound Pressure ◽  
Tap Water ◽  
Acoustic Energy ◽  
Underwater Sound ◽  
Underwater Noise ◽  
Energy Characteristics ◽  
Sound Energy ◽  
Dipole Radiation ◽  
Series Of Experiments

Underwater noise produced by rainfall is an important component of underwater ambient noise. For example, the existence of rainfall noise causes strong disturbances to sonar performance. The underwater noise produced by a single raindrop is the basis of rainfall noise. Therefore, it is necessary to study the associated underwater noise when drops strike the water surface. Previous research focused primarily on the sound pressure and frequency spectrum of underwater noise from single raindrops, but the study on its sound energy is insufficient. The purpose of this paper is to propose a method for predicting the acoustic energy generated by raindrops of any diameter. Here, a formula was derived to calculate the underwater sound energy radiated by single raindrops based on a dipole radiation pattern. A series of experiments were conducted to measure the underwater sound energy in a 15 m × 9 m × 6 m reverberation tank filled with tap water. The analysis of the acoustic energy characteristics and conversion efficiency from kinetic to acoustic energy helped develop the model to predict the average underwater sound energy radiated by single raindrops. Using this model, the total underwater sound energy of all raindrops during a rainfall event can be predicted based on the drop size distribution.

scholarly journals Effect of cannulation site on emboli travel during cardiac surgery

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Mira Puthettu ◽  
Stijn Vandenberghe ◽  
Stefanos Demertzis
Keyword(s):  
Cardiac Surgery ◽  
In Vitro Study ◽  
Blood Stream ◽  
Air Bubbles ◽  
Arterial Tree ◽  
Air Bubble ◽  
Cannulation Site ◽  
The Brain

Abstract Background During cardiac surgery, micro-air emboli regularly enter the blood stream and can cause cognitive impairment or stroke. It is not clearly understood whether the most threatening air emboli are generated by the heart-lung machine (HLM) or by the blood-air contact when opening the heart. We performed an in vitro study to assess, for the two sources, air emboli distribution in the arterial tree, especially in the brain region, during cardiac surgery with different cannulation sites. Methods A model of the arterial tree was 3D printed and included in a hydraulic circuit, divided such that flow going to the brain was separated from the rest of the circuit. Air micro-emboli were injected either in the HLM (“ECC Bubbles”) or in the mock left ventricle (“Heart Bubbles”) to simulate the two sources. Emboli distribution was measured with an ultrasonic bubble counter. Five repetitions were performed for each combination of injection site and cannulation site, where air bubble counts and volumes were recorded. Air bubbles were separated in three categories based on size. Results For both injection sites, it was possible to identify statistically significant differences between cannulation sites. For ECC Bubbles, axillary cannulation led to a higher amount of air bubbles in the brain with medium-sized bubbles. For Heart Bubbles, aortic cannulation showed a significantly bigger embolic load in the brain with large bubbles. Conclusions These preliminary in vitro findings showed that air embolic load in the brain may be dependent on the cannulation site, which deserves further in vivo exploration.

scholarly journals Internal melt figures in ice by rapid adiabatic compression

1994 ◽  
Vol 40 (134) ◽  
pp. 132-134
Author(s):  
R.E. Gagnon ◽  
C. Tulk ◽  
H. Kiefte
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Adiabatic Compression ◽  
Air Bubbles ◽  
Water Ice ◽  
Deep Focus ◽  
And Behavior ◽  
First Time

AbstractSingle crystals and bicrystals of water ice have been adiabatically pressurized to produce, and clearly illustrate, two types of internal melt figures: (1) dendritic figures that grow from nucleation imperfections on the specimen’s surface, or from air bubbles at grain boundaries, into the ice as pressure is elevated; and (2) compression melt fractures, flat liquid-filled disks, that nucleate at imperfections in the crystal and grow with the application of pressure eventually to sprout dendritic fingers at the periphery. The transparency of the ice permitted visualization of the growth and behavior of the figures, and this could be an important tool in understanding the role of phase transformations in deep-focus earthquakes. Correlation between figure size and pressure is noted for the first time.

Sending Blood Gas Specimens Through Pressurized Transport Tube Systems Exaggerates the Error in Oxygen Tension Measurements Created by the Presence of Air Bubbles

1995 ◽  
Vol 81 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Michael H. McKane ◽  
Peter A. Southorn ◽  
Paula J. Santrach ◽  
Mary F. Burritt ◽  
David J. Plevak
Keyword(s):  
Oxygen Tension ◽  
Air Bubbles ◽  
Blood Gas ◽  
Transport Tube

Experiments on air bubbles injection into a vertical shell and coiled tube heat exchanger; exergy and NTU analysis

2015 ◽  
Vol 103 ◽  
pp. 973-980 ◽  
Author(s):  
Hamed Sadighi Dizaji ◽  
Samad Jafarmadar ◽  
Majid Abbasalizadeh ◽  
Saleh Khorasani
Keyword(s):  
Heat Exchanger ◽  
Air Bubbles ◽  
Coiled Tube ◽  
Tube Heat Exchanger

Impeding effect of air bubbles on normal grain growth of ice

2012 ◽  
Vol 42 ◽  
pp. 184-193 ◽  
Author(s):  
Nobuhiko Azuma ◽  
Tutomu Miyakoshi ◽  
Syuhei Yokoyama ◽  
Morimasa Takata
Keyword(s):  
Grain Growth ◽  
Air Bubbles
Sign in / Sign up

Export Citation Format

Share Document