A contrast source method for nonlinear acoustic wave fields in media with spatially inhomogeneous attenuation

Experimental data reveals that attenuation is an important phenomenon in medical ultrasound. Attenuation is particularly important for medical applications based on nonlinear acoustics, since higher harmonics experience higher attenuation than the fundamental. Here, a method is presented to accurately solve the wave equation for nonlinear...

Measurement of sewer sediments with acoustic technology: From laboratory to field experiments

Monitoring sewer sediments is necessary to better understand sedimentation and erosion processes. Sonar is one of the available techniques to proceed to sewer sediment measurements. Extraction of numerical data, implementation of a new algorithm to identify the water-sediment interface, laboratory and field experiments have been done to...

Performance of structural glass at elevated temperatures: A research into the Young’s modulus of glass and the effect of coatings on laminated glass panels at elevated temperatures

Nowadays glass is more commonly applied as structural element, either as a replacement for, or in collaboration with conventional building materials such as steel, aluminium, timber and concrete. Key arguments to opt for glass in structural design are sustainability, aesthetics and transparency. As for all structural elements, glass elements are...

Assessment of Using Low-frequency Ultrasound Device for Domestic Drinking Water Disinfection

Microorganisms may cause problems in drinking water distribution system (DWDS). It is hard to control and always forms the biofilm, which can result in the deterioration of drinking water quality. At household’s tap, due to the favorable conditions, which incurs an easier formation of biofilm. Therefore, the idea of secondary disinfection at...

Transceiver design for reciprocal operation of ultrasonic flow measurement systems

In transit-time ultrasonic flow measurement systems, the system's ability to operate reciprocally in the absence of flow is a highly desirable property. If the reciprocity is lacking in the system, any time delay that appears between the upstream and downstream signals at zero-flow conditions will result in false flow measurement. This...

Estimating P-and S-Wave Velocities in Fluid Mud Using Seismic Interferometry

Fluid mud plays an important role in navigability in ports and waterways. Characterizing and monitoring the seismic properties of the fluid mud can help understand its geotechnical behavior. Estimation of the wave velocities in fluid mud with high accuracy and repeatability enables investigating the behavior of parameters like the yield stress...

In-situ Non-destructive Stiffness Assessment of FRC Materials

Fiber Reinforced Composite (FRC) materials are gaining great popularity in marine structures because of their excellent strength-to-weight ratio, low density, and provided freedom in the design process. However, the use of FRC materials comes along with relatively large uncertainties in material properties and structural integrity after...

Feasibility study of a non-contact, non-destructive testing method to assess the structural integrity of synthetic mooring ropes

Governments are looking more and more to invest in renewable energy sources due to the energy transition that is currently taking place. One of the many renewable energy sources is wind energy which is increasingly positioned at sea. Wind turbines in deep parts of the ocean can be placed on floating structures which are often moored to the sea...