(Press-News.org) Sound waves are commonly used in applications ranging from ultrasound imaging to hyperthermia therapy, in which high temperatures are induced, for example, in tumors to destroy them. In 2010, researchers at Caltech led by Chiara Daraio, a professor of aeronautics and applied physics, developed a nonlinear acoustic lens that can focus high-amplitude pressure pulses into compact "sound bullets." In that initial work, the scientists demonstrated how sound bullets form in solids. Now, they have done themselves one better, creating a device that can form and control those bullets in water.
The nonlinear acoustic lens is constructed from chains strung with stainless-steel spheres that are oriented parallel to one another -- and squeezed together -- to form an array. The gadget was inspired by Newton's cradle, a popular toy that consists of a line of identical balls suspended by wires from a frame. When an end ball is pulled back and released, it slams into the next ball, causing the last ball in the line to fly outward. Similarly, in the acoustic lens, striking one end of the array generates compact nonlinear pulses of sound -- solitary waves that propagate through the lens and can be tightly focused on a target area; when they coalesce at this focal point, they produce a significantly amplified version: the sound bullet. These intense pressure waves may be used to obliterate tumors or kidney stones -- leaving surrounding tissues unharmed -- or probe objects like ship hulls or bridges for unseen defects.
In the new work, the lens has been made more accurate, and a waterproof interface, which efficiently transmitted the pulses, was inserted between the chains and water. "We use water as a target medium with the idea that the acoustic lens could be used for underwater imaging and/or biomedical applications," says postdoc Carly Donahue, who helped refine the device.
"Currently, our work is fundamental in nature. We are focused on demonstrating proof of principle and establishing the technical strengths and weaknesses, which will inform the future design of engineering devices for specific applications," she adds. "For example, using these systems in biomedical applications requires reducing their dimensions and learning about the related scaling effects. Creating commercially viable devices will require the involvement of industrial partners."
Donahue discusses the technology and its potential applications in a talk at the APS Division of Fluid Dynamics Meeting, which will take place November 18-20, 2012 at the San Diego Convention Center, located near the historic Gaslamp District on the waterfront, in San Diego, California. The talk, "An Experimental Study of a Nonlinear Acoustic Lens Interfaced with Water," is at 4:45 pm on Sunday, November 18, 2012, in Room 30E.
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MORE MEETING INFORMATION
The 65th Annual Meeting of the American Physical Society (APS) Division of Fluid Dynamics will take place from November 18-20, 2012, in San Diego, Calif. It will bring together researchers from across the globe to address some of the most important questions in modern astronomy, engineering, alternative energy, biology, and medicine. All meeting information, including directions to the Convention Center, is at: http://apsdfd2012.ucsd.edu/
USEFUL LINKS
Main Meeting Web Site: http://apsdfd2012.ucsd.edu/
Searchable Abstracts: http://meeting.aps.org/Meeting/DFD12/APS_epitome
Directions and Maps: http://apsdfd2012.ucsd.edu/?page=Venue_and_Maps
PRESS REGISTRATION
Credentialed full-time journalists and professional freelance journalists working on assignment for major publications or media outlets are invited to attend the conference free of charge. If you are a reporter and would like to attend, please contact Charles Blue (cblue@aip.org, 301-209-3091).
SUPPORT DESK FOR REPORTERS
A media-support desk will be available. Press announcements and other news will be available in the Virtual Press Room (see below).
VIRTUAL PRESS ROOM
The APS Division of Fluid Dynamics Virtual Press Room will be launched in mid-November and will feature news releases, graphics, videos, and other information to aid in covering the meeting on site and remotely. See: http://www.aps.org/units/dfd/pressroom/index.cfm
GALLERY OF FLUID MOTION
Every year, the APS Division of Fluid Dynamics hosts posters and videos that show evocative images and graphics from either computational or experimental studies of flow phenomena. The outstanding entries are selected for their artistic content, originality, and ability to convey information. They will be honored during the meeting, placed on display at the 2013 APS March Meeting, and appear in the annual Gallery of Fluid Motion article in the American Institute of Physics' journal, Physics of Fluids.
Selected entries from the Gallery of Fluid Motion will be hosted as part of the Fluid Dynamics Virtual Press Room. In mid-November, when the Virtual Press Room is launched, another announcement will be sent out.
This release was prepared by the American Institute of Physics (AIP) on behalf of the American Physical Society's (APS) Division of Fluid Dynamics (DFD).
ABOUT THE APS DIVISION OF FLUID DYNAMICS
The Division of Fluid Dynamics of the American Physical Society (APS) exists for the advancement and diffusion of knowledge of the physics of fluids with special emphasis on the dynamical theories of the liquid, plastic and gaseous states of matter under all conditions of temperature and pressure. See: http://www.aps.org/units/dfd/ END
November 19, 2012, Shenzhen, China – An international research team led by Nanjing Agricultural University and BGI, has completed the first genomic sequence of pear by an approach using the combination of BAC-by-BAC strategy and next-gen sequencing. The pear genome not only provides an invaluable new resource for breeding improvement of this important crop, but also sheds new light on the genome evolution and other genome-wide comparative studies. The results were published online in Genome Research.
As one of the oldest fruit crops, pear has more than 3,000 years of cultivation ...
It is hypothesized that cocoons attached to any material were transported by air, eg by NATO aircraft, after which the moths found their favourite hostplant commonly planted.
The finding of an unknown small moth by Dutch amateur moth hunter Hans Huisman in his backyard lead to the discovery that the American Oak skeletonizer (Bucculatrix ainsliella) is invading North West Europe on planted Northern Red oaks (Quercus rubra), a North American tree.
"The finding is unusual", says Erik J van Nieukerken of Naturalis Biodiversity Center (Leiden, Netherlands), "because until ...
These are some of the results of a report for the World Bank, conducted by the Potsdam Institute for Climate Impact Research (PIK) and Climate Analytics in Berlin. The poorest in the world are those that will be hit hardest, making development without climate policy almost impossible, the researchers conclude.
"The planetary machinery tends to be jumpy, this is to respond disproportionately to disruptions that come with the manmade greenhouse effect," PIK's director Hans Joachim Schellnhuber points out. "If we venture far beyond the 2-degree guardrail, towards 4 degrees, ...
VIB researchers from UGent and Vrije Universiteit Brussel , together with a team of the firm Oxyrane have developed a new technology that can lead to a more efficient and possibly also cheaper therapy for diseases such as Pompe disease. Oxyrane will now start developing a clinical program for this therapy in Pompe disease.
Nico Callewaert (VIB-UGent): "By combining natural processes and proteins of two microbes and a plant we have improved the technology to produce enzymes that patients with metabolic disorders can't produce themselves. We played with the sugar structures ...
The answer is yes. Finnish researchers have developed a triumphant solution for predicting responses of breast cancer cells to a set of cancer drugs. The prediction is based on the genomic profiles of the cancer cells. Harnessing genomic profiles of cells in choosing the best treatment is considered the holy grail of personalised medicine.
The team led by Professor Samuel Kaski from Helsinki institute of Information Technology (HIIT), a joint research centre of Aalto University and University of Helsinki, Finland, presented its winning solution at the DREAM 2012 conference ...
Male tree frogs like to 'see what they're getting' when they select females for mating, according to a new study by Dr. Michael Reichert from the University of Wisconsin-Milwaukee in the US. His work, which is one of the first to test the importance of vision on male mating behaviors in a nocturnal anuran (frog or toad), is published online in Springer's journal Behavioral Ecology and Sociobiology.
Animals display a number of courtship behaviors and are able to modulate these behaviors depending on the likelihood of mating. For example, displaying males may increase the ...
A new study from Karolinska Institutet in Sweden shows, that a technique for measuring bone density called digital X-ray radiogrammetry (or DXR) used on standard hand radiographs can help to identify patients with a higher risk of hip fracture. The researchers believe that DXR, which is fully comparable with other, more costly methods, can be used preventively to identify people in the risk zone for osteoporosis – a disease estimated to effect some 200 million women worldwide.
Each year, approximately 1.7 million hip fractures occur worldwide (about 18,000 only in Sweden), ...
Scientists at the University of Southampton are pioneering a technique to predict when an ecosystem is likely to collapse, which may also have potential for foretelling crises in agriculture, fisheries or even social systems.
The researchers have applied a mathematical model to a real world situation, the environmental collapse of a lake in China, to help prove a theory which suggests an ecosystem 'flickers', or fluctuates dramatically between healthy and unhealthy states, shortly before its eventual collapse.
Head of Geography at Southampton, Professor John Dearing ...
A large-scale international study involving French researchers from the Inserm-Institut Pasteur Lille-Université Lille Nord de France "Public health and molecular epidemiology of ageing-related diseases" joint research unit led by Philippe Amouyel, has just discovered a gene for susceptibility to a rare disease that causes susceptibility to a common one, Alzheimer's disease, providing evidence of the heterogeneous aetiology of Alzheimer's disease.
This whole-exome sequencing approach is explained in detail in The New England Journal of Medicine dated 14 November 2012. ...
ANN ARBOR, Mich. — Could the emergency room be a good place to spot undiagnosed eating disorders among teens, and help steer them to treatment? A new study from the University of Michigan suggests that could be the case.
Researchers screened more than 940 teens and young adults aged 14 years to 20 years for eating disorders, as part of their visit to the U-M Emergency Department for any non-psychiatric reason.
They found that 16 percent – more than one in every 6 – had indications of an eating disorder. Those that did were also much more likely to also show signs ...
