Formulation and Acoustic Modulation of Optically Vaporized Perfluorocarbon Nanodroplets

10.3791/62814 ◽  
2021 ◽  
Author(s):  
Andrew Zhao ◽  
Jeungyoon Lee ◽  
Stanislav Emelianov
Keyword(s):  
Acoustic Modulation

scholarly journals Full life-cycle monitoring and earlier warning for bolt joint loosening using modified vibro-acoustic modulation

2022 ◽  
Vol 162 ◽  
pp. 108054
Author(s):  
Xiaoshu Qin ◽  
Chang Peng ◽  
Gaozheng Zhao ◽  
Zengye Ju ◽  
Shanshan Lv ◽  
...  
Keyword(s):  
Life Cycle ◽  
Full Life Cycle ◽  
Full Life ◽  
Acoustic Modulation ◽  
Cycle Monitoring

scholarly journals Speakers exhibit a multimodal Lombard effect in noise

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James Trujillo ◽  
Asli Özyürek ◽  
Judith Holler ◽  
Linda Drijvers
Keyword(s):  
Motion Capture ◽  
Natural Environment ◽  
Language Use ◽  
Human Language ◽  
Visual Channel ◽  
Lombard Effect ◽  
Face To Face ◽  
Acoustic Analyses ◽  
Acoustic Modulation ◽  
Action Verbs

AbstractIn everyday conversation, we are often challenged with communicating in non-ideal settings, such as in noise. Increased speech intensity and larger mouth movements are used to overcome noise in constrained settings (the Lombard effect). How we adapt to noise in face-to-face interaction, the natural environment of human language use, where manual gestures are ubiquitous, is currently unknown. We asked Dutch adults to wear headphones with varying levels of multi-talker babble while attempting to communicate action verbs to one another. Using quantitative motion capture and acoustic analyses, we found that (1) noise is associated with increased speech intensity and enhanced gesture kinematics and mouth movements, and (2) acoustic modulation only occurs when gestures are not present, while kinematic modulation occurs regardless of co-occurring speech. Thus, in face-to-face encounters the Lombard effect is not constrained to speech but is a multimodal phenomenon where the visual channel carries most of the communicative burden.

scholarly journals Wideband acoustic modulation using periodic poroelastic composite structures

2020 ◽  
pp. 115846
Author(s):  
Hou Qiao ◽  
Zeng He ◽  
Wen Jiang ◽  
Lin Yang ◽  
Weicai Peng
Keyword(s):  
Composite Structures ◽  
Acoustic Modulation

A new vibro-acoustic modulation technique for closed crack detection based on electromagnetic loading

2020 ◽  
Vol 157 ◽  
pp. 107004 ◽  
Author(s):  
Chuang Zhang ◽  
Longlong He ◽  
Suzhen Liu ◽  
Qingxin Yang
Keyword(s):  
Crack Detection ◽  
Closed Crack ◽  
Modulation Technique ◽  
Acoustic Modulation

Experimental investigation of modulation effects for contact-type interfaces in vibro-acoustic modulation tests

2019 ◽  
pp. 147592171985762
Author(s):  
Andrzej Klepka ◽  
Kajetan Dziedziech ◽  
Jakub Mrówka ◽  
Jakub Górski
Keyword(s):  
Experimental Investigation ◽  
Contact Type ◽  
Acoustic Modulation

scholarly journals Vibro-acoustic modulation and data fusion for localizing alkali–silica reaction–induced damage in concrete

2020 ◽  
Vol 19 (6) ◽  
pp. 1905-1923
Author(s):  
Pranav Karve ◽  
Sarah Miele ◽  
Kyle Neal ◽  
Sankaran Mahadevan ◽  
Vivek Agarwal ◽  
...  
Keyword(s):  
Mechanical Damage ◽  
Heterogeneous Material ◽  
Thin Plates ◽  
Alkali Silica Reaction ◽  
Damage Localization ◽  
Frequency Spectra ◽  
Multiple Test ◽  
Damage Probability ◽  
Acoustic Modulation ◽  
Damage In Concrete

This article investigates the application of vibro-acoustic modulation testing for diagnosing damage in concrete structures. The vibro-acoustic modulation technique employs two excitation frequencies on a structure. The interaction of these excitations in the measured response indicates damage through the presence of sidebands in the frequency spectra. Past studies using this technique have mostly focused on metals and composites (thin plates or laminates). Our research focuses on concrete, which is a highly heterogeneous material susceptible to a variety of chemical, physical, and mechanical damage processes. In particular, this article investigates diagnosing cracking in concrete from an expansive gel produced by an alkali–silica reaction in the presence of moisture. Past studies have been limited to damage detection using vibro-acoustic modulation testing, whereas this article extends the technique to damage localization. A cement slab with pockets of reactive aggregate is used to investigate the diagnosis technique. The effects of different testing parameters, such as locations, magnitudes, and frequencies of the two excitations, are analyzed and incorporated in the damage localization methodology. A Bayesian probabilistic methodology is developed to fuse the information from multiple test configurations in order to construct damage probability maps for the test specimen. The results of vibro-acoustic modulation–based damage localization are validated by petrographic study of cores taken from the slab.

Influence of low-frequency parameter changes on nonlinear vibro-acoustic wave modulations used for crack detection

2017 ◽  
Vol 17 (2) ◽  
pp. 218-226 ◽  
Author(s):  
Bin Liu ◽  
Zhiwei Luo ◽  
Tie Gang
Keyword(s):  
Crack Detection ◽  
Crack Opening ◽  
Low Frequency ◽  
Intensity Variation ◽  
Sine Wave ◽  
Dynamic Strain ◽  
Low Frequency Vibration ◽  
Test Parameters ◽  
Increased Sensitivity ◽  
Acoustic Modulation

The use of vibro-acoustic modulation is an effective nonlinear and nondestructive approach to the detection and monitoring of cracks in fatigued, defective, and fractured materials. However, the vibro-acoustic modulation results strongly depend on choice of the testing parameters. To implement this technique for additional applications, the effect of variation in the test parameters must be well understood. This study investigates the influence of variation in the amplitude and frequency of pumping (low-frequency vibration) signals on the modulation. We apply two kinds of probing excitations, sine-wave and swept-signal excitations, and we measure the modulation intensity variation with changes in the relevant parameters to observe their influence on the modulations. Dynamic strain measurement of the crack area is utilized to analyze the relation between the degree of crack opening/closing and the modulation on the crack interface. The results indicate that the probing amplitude has little effect on the modulation, and furthermore, the sweep-signal excitation technique can be used to select the proper probing frequency. The results also indicate that there is a critical pumping strain value ( εc) for the crack samples. When the pumping strain reaches this critical value, the modulation reaches a maximum. However, the opening/closing area cannot increase any more even if the pumping amplitude further increases, and thus, the modulation does not change. The extent of the crack opening/closing also varies with the pumping frequency. Our results suggest that increased sensitivity to crack detection can be achieved with the use of the resonance frequency as the pumping frequency in vibro-acoustic modulation tests.

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