scholarly journals Underwater noise of small personal watercraft (jet skis)

2013 ◽  
Vol 133 (4) ◽  
pp. EL326-EL330 ◽  
Author(s):  
Christine Erbe
Keyword(s):  
Underwater Noise ◽  
Personal Watercraft

scholarly journals Personal Watercraft Incident Court Decisions: The Plaintiff’s Odds?

2021 ◽  
Vol 13 (9) ◽  
pp. 5096
Author(s):  
Eui-Yul Choi ◽  
Woo Jeong Cho
Keyword(s):  
Motor Vehicle ◽  
The United States ◽  
Insurance Companies ◽  
Court Decisions ◽  
Regression Analyses ◽  
Demographic Information ◽  
Slowing Down ◽  
Personal Watercraft ◽  
Successful Adults ◽  
Significant Factors

A personal watercraft (PWC) is a vessel that uses an inboard motor powering a water jet pump as a source of power and is operated by a person sitting, standing, or kneeling. Maneuvering a PWC is different from operating a motor vehicle or boat. An obstacle cannot be avoided by slowing down and turning the watercraft; throttle power is required to turn or maneuver the PWC. The watercraft stops only by drifting or turning sharply. The study examined sixty court decisions published in LexisNexis databases of the United States over the last decade. Cases included individuals injured while operating a PWC as a driver, passenger, or as a result of contact with a watercraft. A content analysis identified items to be used in the study. Crosstab and logistic regression analyses were used to identify demographic information and the characteristics of those who succeeded in a court of law. One-third of the cases were successful; adults, males, and the party who sustained a severe injury were more successful in a court of law with the exception of the statistically significant factors (high risk maneuvers and sharp turns). Among the additional results, we should be aware that insurance companies may not pay; additionally, it is unwise to loan a PWC to a female who has no experience.

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.

Underwater noise measurement and simulation for offshore wind farm in Taiwan

2017 ◽  
Author(s):  
Chih-Hao Wu ◽  
Wei-Chieh Wang ◽  
Yao-Sung Hsu ◽  
Dai-Hua Liu ◽  
Chi-Fang Chen ◽  
...  
Keyword(s):  
Wind Farm ◽  
Noise Measurement ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Underwater Noise

A machine learning-based underwater noise classification method

2021 ◽  
Vol 184 ◽  
pp. 108333
Author(s):  
Guoli Song ◽  
Xinyi Guo ◽  
Wenbo Wang ◽  
Qunyan Ren ◽  
Jun Li ◽  
...  
Keyword(s):  
Machine Learning ◽  
Classification Method ◽  
Underwater Noise ◽  
Noise Classification

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 Bidimensional Ray Tracing Model for the Underwater Noise Propagation Prediction

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Emmanuele D’Andrea ◽  
Maurizio Arena ◽  
Massimo Viscardi ◽  
Tommaso Coppola
Keyword(s):  
Ray Tracing ◽  
Research Collaboration ◽  
Transmission Loss ◽  
International Treaties ◽  
Underwater Noise ◽  
Noise Propagation ◽  
Simulation Code ◽  
Emission Limits ◽  
Propagation Prediction ◽  
Marine Wildlife

An increasing attention has recently been paid to the effect of the underwater noise field generated by ship activities on the marine environment. Although this problem is widely discussed in international treaties and conventions, it has not yet found a consolidated technical-scientific treatment capable of quantifying the level of underwater noise emissions produced by naval systems. As part of a national research collaboration, a novel code has been developed to predict noise propagation according to the Ray Tracing approach. Such optical geometry-based technique allows for calculating the Transmission Loss (TL) trend in its respective contributions: geometrical loss (due to the distance between the source and receiver), dissipation loss (due to the characteristics of the propagation environment), and reflection loss (due to the surfaces that delimit the field). The simulation requires as input parameters the source info as spatial position, frequency, and sound pressure level (SPL) as well as the sea properties like seabed depth, the speed of sound profile, the layers thickness the water column is divided into, the sea salinity, temperature, and pH. The simulation code provides the SPL spatial distribution useful as a fast industrial tool in the future studies addressed to identify the emission limits for the protection of marine wildlife.

A REVIEW OF PRACTICAL METHODS FOR REDUCING UNDERWATER NOISE POLLUTION FROM LARGE COMMERCIAL VESSELS

2021 ◽  
Vol 154 (A2) ◽  
Author(s):  
R C Leaper ◽  
M R Renilson
Keyword(s):  
Noise Pollution ◽  
Operating Conditions ◽  
Wake Flow ◽  
Underwater Noise ◽  
Data Set ◽  
Marine Life ◽  
Propeller Design ◽  
Widespread Agreement ◽  
Noise Measurements ◽  
Considerable Concern

Underwater noise pollution from shipping is of considerable concern for marine life, particularly due to the potential for raised ambient noise levels in the 10-300Hz frequency range to mask biological sounds. There is widespread agreement that reducing shipping noise is both necessary and feasible, and the International Maritime Organization is actively working on the issue. The main source of noise is associated with propeller cavitation, and measures to improve propeller design and wake flow may also reduce noise. It is likely that the noisiest 10% of ships generate the majority of the noise impact, and it may be possible to quieten these vessels through measures that also improve efficiency. However, an extensive data set of full scale noise measurements of ships under operating conditions is required to fully understand how different factors relate to noise output and how noise reduction can be achieved alongside energy saving measures.

Practical Techniques for Reducing the Underwater Noise Pollution Generated by Commercial Ships

2012 ◽  
Author(s):  
M Renilson ◽  
◽  
R Leaper ◽  
O Boisseau ◽  
◽  
...  
Keyword(s):  
Noise Pollution ◽  
Underwater Noise

Managing vessel-generated underwater noise to reduce acoustic impacts to killer whales

2021 ◽  
Vol 150 (4) ◽  
pp. A252-A252
Author(s):  
Krista Trounce ◽  
Alexander MacGillivray ◽  
Jason Wood
Keyword(s):  
Underwater Noise ◽  
Killer Whales
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