Low-frequency broadband noise generated on a railway vehicle by the wheel rail interaction could be a big annoyance for passengers in sleeping cars.
This paper investigates two-dimensional periodic lattices as a means to induce strongly directional stress wave propagation in solids in the low-frequency broadband regime.
This paper presents a detailed theoretical model and in-depth analysis of a bistable frequency up-converting harvester, providing a fundamental understanding and guidance for low-frequency broadband energy harvester design.
In general, the results indicate that tuned mass-spring-damper systems have great potential to reduce the broadband low frequency vibration and acoustic response of vibro-acoustic systems.
To assess hearing in this model, we measured auditory brainstem response (ABR) thresholds to click (broadband low frequency), 8, 16 and 32 kHz tone-pip stimuli in wild-type, heterozygous and homozygous Fgfr3 P244R mice in four different genetic backgrounds (Fig. 2).
The set of equal-annoyance curves obtained in this study showed that the dB(A) unit underestimated annoyance for a broadband continuous low frequency noise by 3 dB for levels around 65 dB(Lin) and by 6 dB for levels around 70 dB(Lin).
Kinetic energy harvesting has drawn great attention in the past decade, but low-frequency and broadband operation is still a big issue which impedes this technology to be widely deployed in low-power Internet of Things applications.
A new digital low-frequency receiver system has been developed at Wuhan University for sensitive reception of low-latitude broadband Extremely Low Frequency (ELF) and Very Low Frequency (VLF) radio waves originating from either natural or artificial sources.
For the ~ 60km preceding entry into the polar cap the payload array encountered a region of intense, Alf´ nic e aurora which was characterized by large, fluctuating DC electric and magnetic fields, field-aligned auroral electron bursts, broadband extremely low frequency plasma wave emissions and elevated ion temperatures.
