Since the depth of surface-breaking cracks often determines the remairring life of a part, the characterization of surface-breaking cracks is a key problern in nondestructive evaluation. Eddy currents have been used for this purpose [1]. However, traditional eddy current methods have poor success when the dimensions of the crack are small compared with the inner radius of the eddy current probe...

Abstract: WDM transmission performance can be monitored efficiently by blind signal separation methods based on higher-order statistics for WDM-channel extraction. Relative to a recent method, our procedure has reduced complexity, no stability problems, and better performance. c © 2002 Optical Society of America OCIS codes: (060.4510) Optical communications; (070.6020) Signal processing; (070.6...

The thickness and spectral dependence of the complex refractive index of upper layer in thin-film MBE-grown GaAs heterostructures were calculated basing on a classical oscillatory model of dielectric function from spectra measured by spectroscopic ellipsometry (nondestructive, contactless optical method) in the range of 1.5-4.75 eV.

Nondestructive testing and defect detection using optical techniques has been extensively investigated. This communication presents a simple method for defect detection in deformed circular plates using moiré deflectometry. The experimental arrangement is simple, inexpensive and does not require elaborate vibration isolation requirements.

This paper presents a possibility to use Resonant Ultrasound Spectroscopy as nondestructive evaluation method for ceramic elements of prosthesis such as ceramic femoral heads. With this method can be emphasized the incorrect sintering of these elements as well as eventually cracks. If the number of resonance peaks is big enough, the elements of elasticity matrix can be determined, demonstrated ...

A concrete bridge over Interstate 70 east of Denver, Colorado was impacted by a fork lift being transported by a truck moving at a speed of approximately 75 mph. The forklift impacted the east face of the prestressed concrete I-beam bridge girder, resulting in severe cracking and concrete spalling on both sides of the eastmost girder. Polymer-modified repair mortar was used to repair spalled ar...

Collecting reef-associated invertebrates usually involves disturbance of the reef area, often damaging the habitat and sometimes damaging live corals. We introduce a nondestructive, inexpensive, and effective method for collecting coral reef-associated invertebrates using approximations of small coral heads constructed of concrete, PVC pipes, nylon cleaning pads, and other materials easily obta...

In this paper the principle and experimental process of the infrared thermal wave nondestructive testing (NDT) on carbon fiber reinforced silicon carbide (Cf /SiC) ceramic matrix composite sample are demonstrated. The experiment results compared with X-ray testing results show that the infrared thermal wave NDT is an effective method for the Cf /SiC ceramic matrix composite, and it can be used ...

This thesis proposes a quantitative method to optimize inspection/repair intervention in rail defect management. Rail defect management is important for track maintenance, since rails are the most significant and basic component of the track systems. Rail inspection is a fundamental intervention to prevent rail failure. Railroads have evolved the rail inspection interval based on their empirica...

The paper carried a brief overview of artificial intelligence algorithms applicable to nondestructive testing. It focuses on two methods: artificial neural networks and fuzzy logic. Selected examples of applications of these methods in digital radiography and eddy current method are given.