Search results
Results From The WOW.Com Content Network
Liquids have a higher dielectric constant than gas; when an air bubble is in a fluid-filled tube the capacitance is reduced and the output voltage rises. [3] The size of the bubble is inversely related to the measured capacitance. Table 1 shows an example of the characteristics of a particular capacitive sensor being researched. [4]
An important factor is that the bubble contains mainly inert noble gas such as argon or xenon (air contains about 1% argon, and the amount dissolved in water is too great; for sonoluminescence to occur, the concentration must be reduced to 20–40% of its equilibrium value) and varying amounts of water vapor.
This bubble is sustained in a standing acoustic wave of moderate pressure, approximately 1.5 atm. [9] Since cavitation does not normally occur at these pressures the bubble may be seeded through several techniques: Transient boiling through short current pulse in nichrome wire. A small jet of water perturbs the surface to introduce air bubbles.
Gargamelle was a heavy liquid bubble chamber detector in operation at CERN between 1970 and 1979. It was designed to detect neutrinos and antineutrinos, which were produced with a beam from the Proton Synchrotron (PS) between 1970 and 1976, before the detector was moved to the Super Proton Synchrotron (SPS). [1]
Schematic view of a flow sensor. An ultrasonic flow meter is a type of flow meter that measures the velocity of a fluid with ultrasound to calculate volume flow. Using ultrasonic transducers, the flow meter can measure the average velocity along the path of an emitted beam of ultrasound, by averaging the difference in measured transit time between the pulses of ultrasound propagating into and ...
The gas-filled microbubbles, typically air or perfluorocarbon, oscillate, and vibrate if a sonic energy field is applied and may reflect ultrasound waves. This distinguishes the microbubbles from surrounding tissues. Because gas bubbles in liquid lack stability and would therefore quickly dissolve, microbubbles are typically encapsulated by shells.
The envelope detector has several drawbacks: The input to the detector must be band-pass filtered around the desired signal, or else the detector will simultaneously demodulate several signals. The filtering can be done with a tunable filter or, more practically, a superheterodyne receiver; It is more susceptible to noise than a product detector
The Minnaert resonance [1] [2] [3] is a phenomenon associated with a gas bubble pulsating at its natural frequency in a liquid, neglecting the effects of surface tension and viscous attenuation. It is the frequency of the sound made by a drop of water from a tap falling in water underneath, trapping a bubble of air as it falls.