When dealing in ultrasonic testing with inhomogeneous material structure data interpretation can be rather difficult. This is especially the case when using anisotropic dissimilar welds made from austenitic steel or nickel based alloys, which are currently used for modern power plant concepts. For better understanding of the complex interaction between the sound field and the component under te...

If the shots deviate from the center and are distributed, the method is unprecise and inaccurate. If the dispersion is small, but beside the target, the method is precise but not accurate. Standardisation of methods is a way to improve the precision. More complex and scientific methods may be more accurate, but they offer many screws to adjust the result – different persons will get different r...

Sound propagat ion in di lute pure gases, b o t h m o n a t o m i c a n d p o l y a t o m i c , has been considered f r o m the po int o f v iew o f the W a l d m a n n S n i d e r equat ion . It is shown that the c o m m o n l y e m p l o y e d assumption that sound propagat ion in gases is equ iva lent t o the propagat i on o f plane waves is val id o n l y in the region where collisions rest...

Reverberation graphs is a novel approach to estimate global soundpressure decay and auralize corresponding reverberation effects in interactive virtual environments. We use a 3D model to represent the geometry of the environment explicitly, and we subdivide it into a series of coupled spaces connected by portals. Off-line geometrical-acoustics techniques are used to precompute transport operato...

In the recent years, we have shown that cylindrical biological membranes such as nerve axons under physiological conditions are able to support stable electromechanical pulses called solitons. These pulses sharemany similarities with the nervous impulse, for example, thepropagationvelocityaswell as themeasured reversibleheatproductionandchanges in thickness and length that cannot be explained w...

Numerical solutions have been obtained for the exact equations describing the propagation of periodic axisymmetric waves in a rigid cylindrical tube. Results were obtained for air over a range of conditions corresponding to shear wave numbers (s = Rm) from 0.2 to 5000 and reduced frequencies (k = oR/a) from 0.01 to 6. For conciseness and convenient application, the results for the attenuation a...

The potential of forests or narrow belts of trees alongside surface transport corridors for reducing noise is often dismissed. Partly this is a consequence of conflicting experimental evidence. But also it is the result of incomplete understanding of the various attenuation mechanisms involved and, therefore, of how they could be exploited and used together in tree planting schemes. First exper...