Acoustical properties, quality

Optimum structure acoustic properties. Quality ride characteristics... 

FFT spectra contain an abundance of potential information (as a function of frequency) related to the process/products characterized by the acoustic sensors. FFT spectra constitute fit for purpose input to any chemometric data analytical method deemed beneficial for making the final model relating the acoustic emissions (vibrations), X, to the salient functional properties (quality, quantity) of the products or process... 

Clay makes an excellent material for didjeridus. Although fired clay is rigid, and even brittle, compared to other materials like wood it is also very resonant and has some unique acoustical properties that work well-suited to didjeridu playing. I use stoneware clay that is best suited to sculpting large forms and fire it to cone 10 , about 2400 degrees Fahrenheit. This produces a vitrified, hard, dense and durable instrument with exceptional resonant qualities. 

Terra cotta products are porous and mechanically resistant. They are marketed raw, enameled or covered with a glaze realized at low temperature, between 600 and 900°C, called varnish. They are appreciated for their esthetic quality, their stability through time and their hygrothermic and acoustic properties. They represent a highly automated industrial sector which is the scene of continual technological developments. 

Hsieh and Plesset assumed that the two-phase homogeneous mixture can be represented as a uniform medium with physical properties synthesized from the constituent phases and weighted according to void fraction, a, and quality, X. Using such a model, they were able to show that the gas compression is essentially isothermal and the acoustic velocity can be approximated as... 

Bauer and Seitzer, 1989b] Bauer, D. and Seitzer, D. (1989b). Statistical properties of high quality stereo signals in the time domain. In Proc. IEEE Int. Conf. Acoust., Speech and Signal Proc, pages 2045 - 2048. 

A basic requirement of burner combusting liquid fuels is a high-quality fuel atomization [9], necessary for complete evaporation and burnout in the area of the flame. If some fuel drops are not evaporated and combusted in the area of flame, concentrations of carbon monoxide and unburned hydrocarbons (UHCs) in flue gas increase rapidly. For the above mentioned reason most liquid fuel burners are designed as diffusion burners with fuel atomized in the combustion chamber. The fuel atomization system itself is rather dependent on physical and chemical properties of fuel and availability of auxiliary atomizing medium. Thus there are three basic types of atomization [10] (i.e., pressure, pneumatic, and rotary atomization). Besides these, there are other, less frequent types of atomization using vibrational, acoustic, ultrasonic, and electrostatic atomizers or flash liquid atomization. 

For a spherical resonator no resonance experiments with laser excitation have been reported so far. However, acoustic excitation of radial modes with a second microphone was accomplished just recently and, as expected, very high Q factors were obtained in a high quality spherical resonator The goal of these experiments was the measurement of thermophysical properties with high precision. A spherical resonator is also an interesting candidate for photoacoustic investigations. 

The laminates of tiK carbon-fiber composite were first characterized by acoustic NDI (C-scan) and optical microscopy to evaluate their quality. Scanning electron microsctqiy (SEM) was used to evaluate laminate quality and nanoparticle distributimi using a Philips XL30 ESEM TMP scanning electron microscope. Mechanical tests fm tiie carbon-fiber composite were selected to measure resin-dominated properties. These tests were transverse four-point flexure with a qian-to-deptii ratio of 32 1 and longitudinal four-point flexure with a qi>an-to-depdi ratio of 16 1 designed to induce mic lane shear failure. Ten qiecimens were tested for each material type and condition. 

---