The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional ...

In order to apply Vibro-acoustography for imaging of arteries, a theoretical model of vibro-acoustics of thick arterial vessels is presented. The arterial wall is modeled with the first order shear deformation theory. The fluids outside and inside the artery are modeled with acoustic wave theory. The coupled vibration of arterial tubes is analyzed with the wave propagation approach. The experim...

results certain correlations were found between fundamental frequency in vowel and total vhi, physical, functional and emotional domains of vhi in group 1 (r = 0.636, 0.649, 0.613 and 0.592 respectively). there was good correlation between speaking fundamental frequency and total vhi and its subscales - except the physical subscale - were also correlated. in group 2, the correlations between ji...

The use of a pulsed fibre laser as an excitation source for photoacoustic tomography has been investigated. Fibre lasers have the advantage of being compact, robust and efficient compared to traditional excitation sources used for photoacoustic tomography (e.g. Q-switched Nd:YAG pumped OPO or dye systems). Their high pulse repetition frequencies and adjustable pulse duration, shape and duty cyc...

A theory of vocal fold oscillation is developed on the basis of the body-cover hypothesis. The cover is represented by a distributed surface layer that can propagate a mucosal surface wave. Linearization of the surface-wave displacement and velocity, and further small-amplitude approximations, yields closed-form expressions for conditions of oscillation. The theory predicts that the lung pressu...

A method is described for solving the inverse problem of determining the profile of an acoustic horn when time-domain reflectance (TDR) is known only at the entrance. The method involves recasting Webster's horn equation in terms of forward and backward propagating wave variables. An essential feature of this method is a requirement that the backward propagating wave be continuous at the wave-f...

During the COVID-19 outbreak, auscultation of heart and lung sounds has played an important role in comprehensive diagnosis real-time monitoring confirmed cases. With clinicians wearing protective clothing isolation wards, a potato chip tube stethoscope, which is secure flexible substitute for conventional been used by Chinese medical workers first-line treatment COVID-19. In this study, optima...

This research presents a model of the avian vocal tract, implemented using classical waveguide synthesis and numerical methods. The vocal organ of the songbird, the syrinx, has a unique topography of acoustic tubes (a trachea with a bifurcation at its base) making it a rather unique subject for waveguide synthesis. In the upper region of the two bifid bronchi lies a nonlinear vibrating membrane...