scholarly journals Scattering and radiation force dependence on properties of empty elastic spherical shells: Low-frequency phase-shift derivation

2019 ◽  
Vol 146 (2) ◽  
pp. EL145-EL150
Author(s):  
Philip L. Marston
Keyword(s):  
Phase Shift ◽  
Low Frequency ◽  
Radiation Force ◽  
Spherical Shells ◽  
Frequency Phase ◽  
Scattering And Radiation

Squeezing-enhanced fiber Mach-Zehnder interferometer for low-frequency phase measurement

2017 ◽  
Vol 110 (2) ◽  
pp. 021106 ◽  
Author(s):  
Fang Liu ◽  
Yaoyao Zhou ◽  
Juan Yu ◽  
Jiale Guo ◽  
Yang Wu ◽  
...  
Keyword(s):  
Phase Measurement ◽  
Low Frequency ◽  
Zehnder Interferometer ◽  
Frequency Phase ◽  
Mach Zehnder Interferometer

Pulse Phase Shift Based Low-Frequency Oscillation Suppression for PT Controlled CCM Buck Converter

2018 ◽  
Vol 65 (10) ◽  
pp. 1465-1469 ◽  
Author(s):  
Dongsheng Yu ◽  
Yisen Geng ◽  
Herbert H. C. Iu ◽  
Tyrone Fernando ◽  
Ruidong Xu
Keyword(s):  
Phase Shift ◽  
Low Frequency ◽  
Buck Converter ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Pulse Phase ◽  
Oscillation Suppression

Influence of Excitation Frequency, Phase Shift, and Duty Cycle on Cooling Ratio in a Dynamically Forced Impingement Jet Array

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Arne Berthold ◽  
Frank Haucke
Keyword(s):  
Phase Shift ◽  
Duty Cycle ◽  
Excitation Frequency ◽  
Liquid Crystal Thermography ◽  
Impingement Jet ◽  
Nusselt Numbers ◽  
Cycle Variation ◽  
The Impact ◽  
Frequency Phase ◽  
Jet Array

Abstract The cooling ratio on a dynamically forced 7 × 7 impingement jet array is studied experimentally. The current study is focused on determining the influence of a phase shift between every row of nozzles as well as the impact of a duty cycle variation on the cooling ratio. Both parameters are studied in dependency of the impingement distance (H/D = 2, 3, 5), the (nozzle-) Reynolds-number (ReD = 3200, 5200, 7200), and the excitation frequency (f = 0 Hz − 1000 Hz). For every set of parameters, the phase shift between every row of nozzles is varied between Φ=0% and 90%, while the variation of the duty cycle is performed between duty cycle (DC) = 35% and 65%. During all investigations, the dimensionless distance between adjacent nozzles is fixed at Sx/D = Sy/D = 5, and liquid crystal thermography is used to acquire the wall temperatures, which are further processed to calculate the local Nusselt numbers. Generally, the implementation of an excitation frequency allows a case-depending increase in the cooling ratio of up to 52%. Further implementation of a phase shift yields an additional frequency-depending improvement of the cooling ratio. In case of duty cycle variation, the best case revealed an additional 19% improvement in the cooling ratio.

A New Design of Signal Source for Crosstalk Test of Multi-Channel Data Acquisition System

2012 ◽  
Vol 246-247 ◽  
pp. 1012-1016 ◽  
Author(s):  
Yan Hu Shan ◽  
Yong Feng Ren ◽  
Guo Yong Zhen ◽  
Xin Quan Jiao
Keyword(s):  
Phase Shift ◽  
Data Acquisition ◽  
Low Frequency ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Signal Source ◽  
Testing Method ◽  
System A ◽  
Rectangular Waveform ◽  
Effective Channel

For the multi-channel data acquisition system, crosstalk significantly affects the sample accuracy. Through analyzing the mode of multiplexer and the sampling timing sequence, we demonstrated that crosstalk effect mainly results from the switch of multiplexer for the low- frequency multi-channel data acquisition system. A new crosstalk testing method based on phase-shift rectangular waveform for the multi-channel data acquisition system was proposed. The phase-shift rectangular waveform was designed. Experiments were conducted to test crosstalk effect of the multi-channel data acquisition system. The experimental results were demonstrated that the proposed approach based on the phase-shift rectangular waveform exhibits a distinct feature in effective channel crosstalk testing, compared with waveforms of other types. Thus, the proposed method is effective to detect crosstalk of the multi-channel data acquisition system.

scholarly journals Medical ultrasound: imaging of soft tissue strain and elasticity

2011 ◽  
Vol 8 (64) ◽  
pp. 1521-1549 ◽  
Author(s):  
Peter N. T. Wells ◽  
Hai-Dong Liang
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Ultrasonic Imaging ◽  
Low Frequency ◽  
Radiation Force ◽  
Breast Disease ◽  
Published Data ◽  
Tissue Strain ◽  
Low Frequency Vibration ◽  
Pulse Echo

After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques—low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)—are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool.

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