1,721,159 research outputs found
Sonar equations for planetary exploration
No full textData for Figure 3 in Ainslie, Michael and Leighton, Timothy (2016) Sonar equations for planetary exploration. The Journal of the Acoustical Society of America</span
Climate change, dolphins, spaceships and antimicrobial resistance: the impact of bubble acoustics
No full textBubbles couple to sound fields to an extraordinary extent, generating and scattering sound, and changing the chemical, physical and biological environments around them when excited to pulsate by an appropriate sound field. This paper accompanies a plenary lecture, opening with the way that the sound emitted by bubbles, when they are injected into the ocean by breaking waves, helps track the >1 billion tonnes of atmospheric carbon that transfers between atmosphere and ocean annually. However, compared to carbon dioxide, atmospheric methane has at least 20 times the ability, per molecule, to generate ‘greenhouse’ warming. Worldwide there is more than twice the amount of carbon trapped in the seabed in the form of methane hydrate than the amount of carbon worldwide in all other known conventional fossil fuels. Acoustics can track the release of bubbles of seabed methane as this hydrate dissociates in response to increasing ocean temperatures, an effect cited by some as a possible climate apocalypse. Continuing the methane theme, this paper discusses the sounds of methane/ethane ‘waterfalls’ on Titan, Saturn’s largest moon, before returning to Earth’s oceans to discuss how whales and dolphins might use the interaction between sound and bubbles when hunting. This in turn suggests possibilities for radar in the search for improvised explosive devices. The paper closes with consideration of another apocalypse, discussing the role that bubbles and acoustics have in mitigating the ‘antibiotic apocalypse’, when in response to the increasing use of antimicrobials (antibiotics to combat bacterial infections; anti-virals for viral infections; anti-fungals for fungal infections; and targeted chemicals to combat parasites) the four classes of microbes all naturally evolve resistance, such that by 2050 Anti-Microbial Resistance will be killing more people than cost the world economy more than the current size of the global economy
Ultrasound in air – guidelines, applications, public exposures and claims of attacks in Cuba and China
No full textThis editorial introduces a Special Issue of the Journal of the Acoustical Society of America, on ‘Ultrasound in Air’. In this Special Issue, one paper covers ways of categorizing the ultrasonic regimes, and three papers cover human effects. One of those three, plus five others, constitute the six papers that report on the measured outputs of commercial devices. Two cover calibration, and the final three papers cover novel applications.This editorial outlines the context in which these papers provide individual studies, including the development of technology and guidelines for safe exposure, and ending with an analysis of what is currently known about claims of sonic attacks on embassy staff in Cuba and China
Bubble acoustics
No full textGas bubbles are the most powerful acoustical sources and sensors that occur naturally in liquids. The potent interaction between bubbles and sound fields is exploited in applications as diverse as monitoring the transfer of greenhouses gases between atmosphere and ocean using the sounds of breaking ocean waves, to monitoring blood flow in the body by scattering ultrasound of bubbles injected into the patient. In the natural world, whales and dolphins go to extraordinary lengths of exploit this potent interaction, for example when trying to trap prey in the bubble nets they blow. Industry exploits this interaction in numerous ways, a new ultrasonic cleaning technology being used as an example
Can we end the threat of anti-microbial resistance once and for all?
No full textWHAT IS ANTI-MICROBIAL RESISTANCE? Microbes that exhibit Anti-Microbial Resistance (AMR) are resistant to existing disinfection cleaning or antimicrobial medication. Specifically, that is when bacteria, viruses, fungi and parasites (of, for example, the type that cause malaria) becoming respectively resistant to antibiotics, antivirals, -anti-fungals, and anti-parasite drugs (the four categories of anti-microbial medication)
Early multidisciplinary research during the 2020 lockdown
No full textIn the early months of the COVID-19 pandemic, a great deal was unknown about the infection and disease and, with much of the country in lockdown, researchers and inventors were investigating ways to reduce the impact of the disease. These included the development of diagnostics, infection prevention tactics, therapeutics and public health measures. This article reports on activities that members of NAMRIP rapidly developed, on their own initiative, in response to the crisis, with a range of funding sources or none
The acoustic bubble: ocean, cetacean and extraterrestrial acoustics, and cold water cleaning
No full textThis paper summarizes the content of a plenary lecture on the author’s personal research into the interactions between bubbles and sound fields, covering particular topics involving the climatically important gas exchange between atmosphere and ocean, the implications of bubbly ocean water to marine mammals that use sound, and the opportunities afforded by incorporating acoustical sensors onto probes launched to investigate other worlds in our solar system. It closes with recent data on the opportunities of bubble acoustics to investigate methods of cold water cleaning
Cold water cleaning in the preparation of food and beverages: the power of shimmering bubbles
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