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A series of flume experiments were conducted to study the effect of bed form dynamics on the flow over a gravel bed comprising a wide distribution of grain sizes. Instantaneous high-frequency streamwise flow velocities were sampled using an acoustic Dopple ...
Upgrades of the CERN particle accelerators complex are planned to increase the potential of physics discovery in the LHC. In this respect, the beam coupling impedances of the SPS and LHC are expected to be among the limitations to the intensity upgrade sch ...
This paper presents an investigation into radio frequency (rf) breakdown for electrodes with holes or protrusions, approximating the situation in real reactors and providing a benchmark for fluid simulations. rf breakdown curves (voltage versus pressure) g ...
In this study B. Zotter’s formalism is applied to a circular infinitely long beam pipe made of a conductor of infinite thickness where an offset point-charge travels at any given speed. Simple formulae are found for the impedances and electromagnetic field ...
A successful approach for designing a compact reconfigurable antenna system using a single active and two parasitic reactance-loaded dipoles is proposed. The switched parasitic antenna (SPA) operates at 2.6 GHz using PIN diode technology. It is designed to ...
In this study, ceramic samples of lead zirconate titanate Pb(Zr0.42Ti0.58)O3 (PZT 42/58) doped with Fe (hard) and Nb (soft) were studied by Raman, infrared (IR) and THz spectroscopy in the temperature range from 900 to 20 K. From the evaluation of the IR a ...
The Global Positioning System (GPS) is a trilateration system which allows to compute the position of a receiver from the time the signals need to propagate from the satellites down to the receiver. Since the Selective Availability (SA) was turned off in 2 ...
Modal acoustics is one of the main sources of annoyance in the low frequency range in rooms. Active noise control techniques can be deployed to reach sufficient acoustic benefit, but limited to a single frequency, whereas broader efficiency would require c ...
Engineers dealing with noise reduction in habitations close to transportation traffic or indus-trial facilities encounter several problems to decrease noise level in rooms at low frequencies. Passive materials and current building construction knowledge en ...
We have identified and studied a pronounced artifact in diffusion-weighted MRI on a clinical system. The artifact results from vibrations of the patient table due to low-frequency mechanical resonances of the system which are stimulated by the low-frequenc ...