PubMed · 14463784
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E LEHNHARDT. 1961. [Acoustic correlation].. https://pubmed.ncbi.nlm.nih.gov/14463784/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We designed an electronic device to monitor calling behavior in male crickets. The device and its associated software can record to disk the activity of as many as 16 individuals simultaneously. The data recorded contain detailed information about the temporal structure of each individual's calls. The temporal resolution achieved with an ordinary PC is good enough to detect and record the occurrence of every pulse of sound from each cricket. The resulting data files are efficient and compact, and so the system is appropriate for experiments lasting many days.
An exact time-domain method is proposed to time reverse a transient scalar wave using only the field measured on an arbitrary closed surface enclosing the initial source. Under certain conditions, a time-reversed field can be approximated by retransmitting the measured signals in a reversed temporal order. Exact reconstruction for three-dimensional broadband diffraction tomography (a linearized inverse scattering problem) is proposed by time-reversing the measured field back to the time when each secondary source is excited. The algorithm is verified by a numerical simulation. Extension to the case using Green's function in a heterogeneous medium is discussed.
In this work, we describe a novel pulse mode shear horizontal-surface acoustic wave (SH-SAW) polymer coated biosensor that monitors rapid changes in both amplitude and phase. The SH-SAW sensors were fabricated on 36 degrees rotated Y-cut X propagating lithium tantalate (36 YX.LT). The sensitivity of the device to both mass loading and visco-elastic effects may be increased by using a thin guiding layer of cross-linked polymer. Two acoustic modes are excited by the electrodes in this crystalline direction. Metallisation of the propagation path of the 36 YX.LT devices allows the two modes to be discriminated. Successive polymer coatings resulted in the observation of resonant conditions in both modes as the layer thickness was increased. Using the 36 YX.LT devices, we have investigated the application of a novel pulse mode system by sensing a sequence of deposition and removal of a biological layer consisting of vesicles of the phospholipid POPC. A continuous wave system was used to verify the accuracy of the pulse mode system by sensing a series of poly(ethylene glycol) (PEG) solutions. The data clearly demonstrates the ability of the 36 YX.LT pulse mode system to provide rapid measurements of both amplitude and phase for biosensing applications.