Dual frequency imaging and therapeutic transducer using an acoustic band-pass filter for application to endoscopic surgery

2011 ◽  
Author(s):  
Takashi Azuma ◽  
Hajime Kenmotsu ◽  
Makoto Hashidume ◽  
Shin-ichiro Umemura
Keyword(s):  
Endoscopic Surgery ◽  
Band Pass Filter ◽  
Dual Frequency ◽  
Pass Filter ◽  
Band Pass

Design of Frequency Selection Circuit of Advanced Detector Receiving Device in Coal Mine Roadway

2015 ◽  
Vol 740 ◽  
pp. 507-510
Author(s):  
Xi Gao Liu ◽  
Zhi Min Liu ◽  
Jin Tao Zhang ◽  
Yi Ming Lv ◽  
You Zhou ◽  
...  
Keyword(s):  
Coal Mine ◽  
Circuit Simulation ◽  
Band Pass Filter ◽  
Dual Frequency ◽  
Pass Filter ◽  
Frequency Selection ◽  
Mine Roadway ◽  
Frequency Components ◽  
Band Pass ◽  
Field Excitation

Coal mine roadway advanced detector, including the transmitting and receiving devices, is a kind of geophysical instrument used in coal mine roadway advanced detection based on the dynamic and directional electric field excitation method. The transmitting device emits dual frequency modulated square wave current into the excavation face and the receiving device receives potential difference of coal and rock medium generated by induced polarization, of which the frequency selection circuit is to filter the interference of the harmonics of the signal and other frequency components. The paper derived expressions of emission current. Considering the actual working conditions, the paper proposed the design requirements of the frequency selection circuit and the scheme of a controller to control multiple frequency selection filter circuits. The paper completed the design of the control circuit consisting of a microcontroller and analog switch MAX313 and the band-pass filter circuit consisting of universal active filter UAF42. According to the circuit simulation and the analysis of the data with software of multisim, it proves the design of circuit meets the requirements.

OBSERVATION AND SIMULATION OF TSUNAMIS INDUCED BY THE 2003 TOKACHI-OKI EARTHQUAKE (M 8.0)

2015 ◽  
Vol 2 (3) ◽  
Author(s):  
Tatsuo Ohmachi ◽  
Shusaku Inoue ◽  
Tetsuji Imai
Keyword(s):  
Rayleigh Wave ◽  
Water Pressure ◽  
Near Field ◽  
Source Region ◽  
Tsunami Source ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Tsunami Simulation ◽  
Sea Bed ◽  
Band Pass

The 2003 Tokachi-oki earthquake (MJ 8.0) occurred off the southeastern coast of Tokachi, Japan, and generated a large tsunami which arrived at Tokachi Harbor at 04:56 with a wave height of 4.3 m. Japan Marine Science and Technology Center (JAMSTEC) recovered records of water pressure and sea-bed acceleration at the bottom of the tsunami source region. These records are first introduced with some findings from Fourier analysis and band-pass filter analysis. Water pressure disturbance lasted for over 30 minutes and the duration was longer than those of accelerations. Predominant periods of the pressure looked like those excited by Rayleigh waves. Next, numerical simulation was conducted using the dynamic tsunami simulation technique able to represent generation and propagation of Rayleigh wave and tsunami, with a satisfactory result showing validity and usefulness of this technique. Keywords: Earthquake, Rayleigh wave, tsunami, near-field

A comparative study on the demodulation capability of a single loop optoelectronic oscillator with and without a dynamic band Pass filter

Optik ◽  
2021 ◽  
Vol 226 ◽  
pp. 165924
Author(s):  
Shantanu Mandal ◽  
Kousik Bishayee ◽  
Arindum Mukherjee ◽  
B N Biswas ◽  
Chandan Kumar Sarkar
Keyword(s):  
Comparative Study ◽  
Band Pass Filter ◽  
Optoelectronic Oscillator ◽  
Pass Filter ◽  
Single Loop ◽  
Band Pass
Sign in / Sign up

Export Citation Format

Share Document