Searched for: subject%3A%22Acoustics%22
(1 - 20 of 911)

Pages

document
Visschers, F.L.L. (author), Massaad, J. (author), van Neer, P.L.M.J. (author), Verweij, M.D. (author), Liu, D. (author), Broer, D.J. (author)
article 2022
document
Kastelein, R.A. (author), de Jong, C.A.F. (author), Tougaard, J. (author), Helder-Hoek, L. (author), Defillet, L.N. (author)
article 2022
document
van Walree, P.A. (author), Colin, M.E.G.D. (author)
A channel sounding and communications experiment was performed in the Oslofjord, using eight bottom-mounted instrument units deployed in a network configuration. Five units were equipped with a software-defined 4–8-kHz acoustic modem, programmed to transmit probe signals and communication packets in a round-robin fashion. All transmitted...
article 2022
document
Quesson, B.A.J. (author), van Neer, P.L.M.J. (author), Tamer, M.S. (author), Hatakeyama, K. (author), van Es, M.H. (author), van Riel, M.C.J.M. (author), Piras, D. (author)
The semiconductor industry needs to fit ever more devices per unit area to improve their performance; hence a trend towards increasingly complex structures by varying material combinations and 3D geometries with increasing aspect ratios. The new materials used may be optically opaque, posing problems for traditional optical metrology methods....
conference paper 2022
document
Blom, K.C.H. (author), Dol, H.S. (author), Berning, F. (author), van Walree, P.A. (author)
For underwater acoustic modems to operate in a time-varying environment, in-mission adaptation is desirable. A physical layer has been designed that supports mechanisms for ad-hoc configuration changes based on (in-situ and indirectly obtained) channel and noise conditions. Coded preambles are used to instruct the receiver of a configuration...
conference paper 2022
document
Kotti, S.E. (author), Heusdens, R. (author), Hendriks, R.C. (author)
The use of wireless acoustic sensor networks (WASNs) has received increased attention over the last decade. The advantages of WASNs over stand-alone multi-microphone devices are that the microphone array is not anymore limited by the dimensions of a single device, and that microphones can be placed at arbitrary locations. One of the...
conference paper 2021
document
Massaad, J. (author), van Neer, P.L.M.J. (author), van Willigen, D.M. (author), Sabbadini, A. (author), de Jong, N. (author), Pertijs, M.A.P. (author), Verweij, M.D. (author)
Current ultrasonic clamp-on flow meters consist of a pair of single-element transducers which are carefully positioned before use. This positioning process consists of manually finding the distance between the transducer elements, along the pipe axis, for which maximum SNR is achieved. This distance depends on the sound speed, thickness and...
article 2021
document
Massaad, J. (author), van Neer, P.L.M.J. (author), van Willigen, D.M. (author), de Jong, N. (author), Pertijs, M.A.P. (author), Verweij, M.D. (author)
Acoustic wave propagation in ultrasonic flow measurements is typically assumed to be linear and reciprocal.However, if the transmitting transducer generates a sufficiently high pressure, nonlinear wave propagation effects become significant. In flow measurements, this would translate into more information to estimate the flow and therefore a...
article 2021
document
Braat-Eggen, E. (author), Reinten, J. (author), Hornikx, M. (author), Kohlrausch, A. (author)
Students can be disturbed by background noise while working in an open-plan study environment. To improve the acoustic quality of open-plan study environments a study was done on the influence of different sound scenarios on students working on a typical student task, “studying for an exam”. Three sound scenarios and a quiet reference sound...
article 2021
document
van Neer, P.L.M.J. (author), Quesson, B.A.J. (author), Tamer, M.S. (author), Hatakeyama, K. (author), van Es, M.H. (author), van Riel, M.C.J.M. (author), Piras, D. (author)
Several methods are being researched to detect and characterize buried nanoscale structures in hard solid samples. The most common acoustic method is acoustic microscopy. An acoustic microscope is based on a single element transducer operating in pulse-echo mode. The acoustic waves are coupled into a sample using a liquid couplant (eg water) and...
article 2021
document
Stoevesandt, B. (author), Schepers, J.G. (author), Sun, Y. (author), Fuglsang, P. (author)
Wind turbine aerodynamics remains to be a central field in the development of wind turbines. It comprises several aspects, and methods to be understood really make the best use of it in today’s wind turbine and wind farm development. This chapter gives an overview of all aspects in wind energy aerodynamics covered within this book and the...
bookPart 2021
document
Sabbadini, A. (author), Caenen, A. (author), Keijzer, L.B.H. (author), van Neer, P.L. (author), Vos, H.J. (author), de Jong, N. (author), Verweij, M.D. (author)
Shear wave elastography (SWE) has the potential to determine cardiac tissue stiffness from non-invasive shear wave speed measurements, important, e.g., for predicting heart failure. Previous studies showed that waves traveling in the interventricular septum (IVS) may display Lamb-like dispersive behaviour, introducing a thickness-frequency...
article 2021
document
Dol, H. (author), Blom, K. (author)
It is a persistent misunderstanding that underwater acoustic communication at short range is always easier than at long range. Same for (quasi) stationary configurations being always easier than dynamic ones. This paper gives examples of high-rate links in very shallow water at several kilometres distance, as well as difficult communication...
conference paper 2021
document
van Es, M.H. (author), Quesson, B.A.J. (author), Mohtashami, A. (author), Piras, D. (author), Hatakeyama, K. (author), Fillinger, L. (author), van Neer, P.L.M.J. (author)
In order to extract ever more performance from semiconductor devices on the same device area, the semiconductor industry is moving towards device structures with increasingly complex material combinations and 3D geometries. To ensure cost effective fabrication of next generation devices, metrology solutions are needed that tackle the specific...
conference paper 2020
document
Müller, R.A.J. (author), von Benda-Beckmann, A.M. (author), Halvorsen, M.B. (author), Ainslie, M.A. (author)
Regulations for underwater anthropogenic noise are typically formulated in terms of peak sound pressure, root-mean-square sound pressure, and (weighted or unweighted) sound exposure. Sound effect studies on humans and other terrestrial mammals suggest that in addition to these metrics, the impulsiveness of sound (often quantified by its kurtosis...
article 2020
document
Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)
This paper focuses on extensive numerical and experimental investigations of a thin sandwich acoustic source. Due to an energy inefficient actuation design, a thin sandwich acoustic source that was proposed in an early study is redesigned and reconstructed in the current research. The thin acoustic source in the present paper is actuated by long...
article 2020
document
Zebregs, M. (author), Mayer, A.E.H.J. (author), van der Heijden, A.E.D.M. (author)
In this comparative study, a solid composite, AN/HTPB-based propellant was prepared by conventional processing in a mechanical mixer and by applying an advanced processing technique relying on resonant acoustic mixing (RAM). After curing of the propellants, cross-sections were prepared and characterized by scanning electron microscopy. Also the...
article 2020
document
Phogat, R. (author), González Díez, N. (author), Smeulers, J.P.M. (author), Casalino, D. (author), Avallone, F. (author)
Impeller rotation, vortex shedding, secondary flows or a combination of these phenomena can lead to the generation of acoustic waves in the compressor cascade causing dynamic pressure loading on the impeller. When the eigenfrequency and eigenmode shape of the acoustic mode match with the structural ones of the impeller, high fatigue stresses and...
conference paper 2020
document
Tajdari, F. (author), Berkhoff, A.P. (author), van der Zee, R.A.R. (author), de Boer, A. (author)
article 2020
document
Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)
This paper studies an acoustic source with a relatively small thickness and a high bending stiffness. The acoustic source operates in the low frequency, quasi-static regime. The focus of the current study is on the actuation part in order to design an appropriate excitation mechanism. A flexural mechanism is modeled in combination with a...
article 2020
Searched for: subject%3A%22Acoustics%22
(1 - 20 of 911)

Pages