Potential Of Acoustic Emission Research Articles

Acoustic emission during the solvent mediated cooling crystallization of citric acid

The potential of Acoustic Emission (AE) for controlling crystallization processes is investigated. The sensing technology is successfully applied to monitor the batch cooling crystallization of citric acid (CA) in water. The solvent-mediated phase transition between the anhydrous and the monohydrated forms of CA is clearly detected from the recorded acoustic measurements. A tremendous amount of acoustic data is recorded by the equipment, and the analysis of the data is focused on the evaluation of AE as a new sensor for monitoring the basic steps of the crystallization processes (i.e., nucleation, growth, phase transition, etc.) A time- and frequency-domain analysis is presented which shows the wealth of the technique. It is finally concluded that AE allows very early detection of nucleation events, provides a means of monitoring the development of the crystallization process and allows monitoring phase transition phenomena obtained through cooling. It is thus suggested that acoustic emission could be valuable in the development of new crystallization monitoring and control strategies: this is all the more interesting that the acoustic piezo-sensor is non-intrusive and does not require any sampling of the slurry, two features which are of tremendous importance in the field of cooling crystallization processes.

Potential of Acoustic Emission in Unsupervised Monitoring of Gas-Fuelled Engines

Abstract: The aim of this paper is to scrutinise closely information that contains in the acoustic emission of a gas-fuelled engine and to define the potential of knock condition detection. The recently introduced technique of nonstationary system identification is investigated. At first, it utilises the wavelet transform to reveal time-frequency energy density of data. Then the modified version of singular value decomposition is applied to extract dominant frequency components from the data buried in background noise. The efficacy of knock feature extraction is investigated using three sources of data: in-cylinder pressure, engine structure vibration and engine noise sensed by a microphone.

Acoustic Emission, a New Sensor for Monitoring Industrial Crystallization Processes

The potential of Acoustic Emission (AE) for monitoring industrial crystallization processes is investigated through the monitoring of two typical crystallization systems. The sensing technology is successfully applied to monitoring the batch cooling solution crystallization of Citric Acid (CA) in water, which exhibits a anhydrous to monohydrate phase transition. The technique is also applied to monitoring the precipitation of salicylic acid from its sodium salt. A huge amount of acoustic data is recorded by the AE system, and the analysis of this data set is focused on the evaluation of AE as a new sensor for monitoring the basic steps of the crystallization process (i.e., nucleation, growth, phase transition, etc.) A time- and frequency domain analysis is presented which shows the wealth of the technique. It is finally concluded that AE allows a very early detection of nucleation events, provides a means of monitoring the development of the crystallization or precipitation process and allows monitoring solvent-mediated phase transition phenomena occurring under cooling. It is thus suggested that acoustic emission could be valuable in the development of new crystallization monitoring and control strategies: this is all the more interesting that the acoustic piezo-sensor is non-intrusive and does not require any sampling of the slurry, two features which are of tremendous importance in the field of cooling crystallization processes.

Intelligent Signal and Image Processing in eHealth

Intelligent Signal and Image Processing in eHealth