Cambridge Ultrasonics - white papers

Of particular interest

Matched filtering of inadvertent and deliberate chirps.
Should scattering losses be included in attenuation?

White Papers

White Papers are technical papers on various subjects relating to ultrasound. They are in pdf format. They are provided as seen. You may download a copy for your own interest but you may not reproduce or publish them in any way for profit.

Title	Content
Fundamentals of ultrasonics	Wave type description and the relationship between wave speed, stiffness and density.
Inspection using ultrasonics	Different ultrasonic inspection methods. Lateral and axial resolution. Universal chirp generation and advantages of matched chirp detection.
Transducers in ultrasonics	Common transducer types. Phased arrays. Time reversal detection.
Waves in ultrasonics	Wave equation and wave speed. Reflection, transmission. Mode conversion. Near field and far field. Attenuation. Doppler effect. Dispersion. Important units.
Modelling of ultrsonic transducers and ultrasonic wave propagation for commercial applications using finite elements with experimental visualization for validation	Paper presented in the conference Comsol Cambridge September 2014, at Churchill College, Cambridge University. The paper deals with some of the difficulties involved with modeling ultrasonic transducers and propagation of ultrasonic waves from the transducers. Problems ultrimately relate to spatial-meshing and time-meshing.
The Erosion of Metals	PhD thesis from 1980 on the subject of solid particle erosion of metallic surfaces. It includes: experimental evidence of target melting as a mechanism of erosion; experimental evidence of erosion at normal impingement with a steel sphere; mathematical theory of the statistical processes in erosion through teh concept of an impact zone; description of the construction of test equipment for performing ersion tests over a range of temperatures from 80 K to 1300 K; projectile speed measurement for signal particles and an erosive jet including corss-correlation methods.
When does a wave arrive?	A whimsical and non-mathematical approach to understanding the complexities of wave propagation related to ultrasound. It draws a loose analogy between what happens to a wave-train or a packet of waves and the kind of train that human beings ride in. The transportation train has to be modified to fit with what a wave-train does and that makes for some weired travelling experiences.
How safe is medical ultrasound?	Ultrasound can be used to examine the human body or to destroy cells, such as cancer. Examination can be changed into treatment by changing the intensity of ultrasound but examination can also be changed inadvertently into damage by non-linear propagation of ultrasound. The incidence of autism has increased in the population since the introduction of ultrasound scanners - is this just a correlation or is it cause and effect? Cheap ultrasound scanners that can be bought over-the-counter in pharmacies by the public may be just around the corner. There is need for care in teh use of the technology.
New golf gaming product	Details of a crowd funding project to develop a novel device for golf-gaming using ultrasound.
No crowd funding for golf	Details and lessons to learn from a failed crod funding project for golf-gaming using ultrasound.
Ultrasound - hear no ultrasound, see no ultrasound ... forget ultrasound?	Part 1 and Part 2 of an article covering the diverse applications of ultrasound and ultrasonic technology. These include vehicle parking sensors, rodent scarers, adolescent scarers, hi-fi loudspeakers, soprano opera singers, audio spotlights, high power ultrasound transducers, stunning fish, cleaning, activating scalpels, massage, breaking kidney stones, processing sewage, breaking open algae cells, cutting patisserie cakes, welding plastic shoes, welding metals, making new chemicals. The application of finite element modelling to the design of ultrasonic devices. Also touched upon is the skill of bats echo-location, human echo-location, medical ultrasound, inspecting pressure vessels and railway tracks, synthetic aperture focusing, non-linear propagation and the visualization of ultrasound.
Development of improved ultrasonic transducers for medical surgery	Paper presented at the conference Comsol Europe 2020 in Paris but held on-line only due to the Covid-10 epidemic. Finite element modeling is used to designe better ultrsonic transducers for cutting bone in orthopaedic surgery. Langevin style of transducers are used. the need to position the mounting plate on a node is important. A modular design approach is compared to a single integrated design. The effect of the cutting blade locking in the bone is considered and so too are vraiations in material properties.