The acoustic emission (AE) signal of wood damage is a kind of weak and highfrequency signal. Hardware circuit design and software programming are necessary for the acoustic emission data acquisition. In order to carry out further analysis, it needs to be preprocessed. The preprocessing hardware system consists of preamplifier, filtering circuit, main amplification circuit and AD converting circ...

The emission enhancement of sound without electronic components has wide applications in a variety of remote systems, especially when highly miniaturized (smaller than wavelength) structures can be used. The recent advent of acoustic metamaterials has made it possible to realize this. In this study, we propose, design, and demonstrate a new class of acoustic cavity using a double-walled metamat...

Article history: Received 6 April, 2015 Accepted 10 October 2015 Available online 11 October 2015 This article provides a method of acoustic emission (AE) technique to detect leakage in pipeline and locate the position of the leakage. The AE sensor is made of piezoelectric effect transducer to pick up the acoustic emission signal which is generated from the turbulent flow at the leak position. ...

The mechanical characteristics of rock salt have an important influence on the safety of the salt cavity. The acoustic emission (AE) technique was used to analyze the generation of microcracks in rock salt under uniaxial compression condition. By monitoring acoustic emission in whole process of stress strain curve under uniaxial compression test, the damage characteristic of rock salt is obtain...

Intense Na* emission was observed from 0.1 M Na(2)SO(4) in 95% sulfuric acid during multibubble sonoluminescence (MBSL). As a function of acoustic intensity, three different morphologies are observed for the cloud of light emitting bubbles. Even more strikingly, there is a spatial separation between blue-white emitting bubbles and orange emitting bubbles, easily observed by the naked eye. Surpr...

Despite long-term efforts to elucidate the mechanisms responsible for age-related hearing loss (AHL), there is currently no available treatment strategy able to provide a cure. Apoptotic cell death, including that of hair cells and spiral ganglion neurons (SGNs) in the cochlea has been proposed to be the classic theory behind the development of AHL. As calcium signaling plays key roles in signa...

Friction fault diagnosis of rotating machinery based on acoustic emission (AE) technique is a research hotspot in recent years. The rotating machinery will produce multi-source noise during the operation process, so how to correctly identify the friction acoustic emission signals has become a key factor for accurate diagnosis of the fault. In this paper, it proposes a Gaussian mixed model (GMM)...

Click-evoked otoacoustic emissions (cEOAEs) were repeatedly recorded in an operational sample of 144 very low birth weight (VLBW) infants. A subgroup of 22 was composed of all those babies in which at least 4 recordings were successfully done. The mean birth weight of this group was 1040 g, and the mean duration of assisted ventilation was 17 days. The OAE-recordings were done in the post conce...