Search results
Results from the WOW.Com Content Network
Ultrasound attenuation spectroscopy is a method for characterizing properties of fluids and dispersed particles. It is also known as acoustic spectroscopy. There is an international standard for this method. [1] [2] Measurement of attenuation coefficient versus ultrasound frequency yields
The attenuation coefficient of a volume, denoted μ, is defined as [6] =, where Φ e is the radiant flux;; z is the path length of the beam.; Note that for an attenuation coefficient which does not vary with z, this equation is solved along a line from =0 to as:
Attenuation coefficients are used to quantify different media according to how strongly the transmitted ultrasound amplitude decreases as a function of frequency. The attenuation coefficient ( α {\displaystyle \alpha } ) can be used to determine total attenuation in dB in the medium using the following formula:
f c is the center frequency of the ultrasound pulse . MI is measured with a calibrated hydrophone in a tank of degassed water. The pulse pressure amplitudes are measured along the central axis of the ultrasound beam. The P r is calculated by reducing it using an attenuation coefficient of 0.3 dB/cm/MHz. [2]
This concepts of ultrasonic proving can be used to inversely resolve the grain size in the time domain when the scattering attenuation coefficient is measured from testing data, providing the non-destructive way to predict material's property with rather simple instruments.
Ultrasound transmission tomography (UTT) is a form of tomography involving ultrasound. [1]Like X-ray tomography, the attenuation of the ultrasound as it passes through the object can be measured, but since the speed of sound is so much lower than the speed of light, the delay as it passes through the object can also be measured, allowing estimation of both the attenuation coefficient and the ...
absorption coefficient is essentially (but not quite always) synonymous with attenuation coefficient; see attenuation coefficient for details; molar absorption coefficient or molar extinction coefficient , also called molar absorptivity , is the attenuation coefficient divided by molarity (and usually multiplied by ln(10), i.e., decadic); see ...
Where is the optical density or attenuation, is emitted light intensity, is measured light intensity, is the attenuation coefficient, [] is the chromophore concentration, is the distance between source and detector and is the differential path length factor, and is a geometric factor associated with scattering.