Superconducting Quantum Interference Devices coupled to gradiometers were used to detect aws in metals. We detected aws in aluminum samples carrying current, measuring elds at lift-o distances up to one order of magnitude larger than the size of the aw. Con gured as a susceptometer we detected surface-braking aws in steel samples, measuring the distortion on the applied magnetic eld. We also us...

Advanced manufacturing and new energy systems are presenting a wide variety of challenges for nondestructive testing and evaluation (NDT/NDE). This paper discusses the state of the art, needs and opportunities for NDE to provide reliable, effective and economic inspection and monitoring for energy systems. It introduces issues of materials, defects and allowables, the evolution of advanced NDT ...

We present a proof-of-principle study about the use of a sensor for the nondestructive monitoring of strength development in hydrating concrete. The nondestructive evaluation technique is based on the propagation of highly nonlinear solitary waves (HNSWs), which are non-dispersive mechanical waves that can form and travel in highly nonlinear systems, such as one-dimensional particle chains. A b...

The aim of this article is to attempt a concise review of the state of the art of the nondestructive biomarkers approach in vertebrates, establishing a consensus on the most useful and sensitive nondestructive biomarker techniques, and proposing research priorities for the development and validation of this promising methodology. The following topics are discussed: the advantages of the use of ...

This article is a companion piece for my first published in the April 2020 issue of Materials Evaluation (https://doi.org/10.32548/2020.me-04136). While that provided broad overview neutron radiography, this delves deeper into mechanics radiation and provides more examples its applications field nondestructive testing.

Nondestructive evaluation (NDE) methods are being developed for ceramic thermal barrier coatings (TBCs) applied to components in the hot-gas path of advanced high-efficiency and low-emission gas turbines, including syn-gas fired turbines. The objectives of the NDE development are to assess TBC condition for quality control as well as to monitor TBC degradation and predict TBC life during servic...

We applied the laser ultrasonic technique for detecting surface breaking slots in steel cylinders (25 mm in diameter). The observation of the detected signal over a long time (500 micros), shows that the interaction of the two contra-propagating incident Rayleigh waves reinforce the echoes coming from the defect. These echoes are slowly growing with time whereas the main signals decrease. This ...

This paper deals with the basic mechanisms of fatigue damage in materials exposed to service and a series of nondestructive techniques for the early detection of this damage. For all materials with reasonably high fracture toughness it is the organized motion of dislocations that either forms extrusions/intrusions (surface roughness) or the piling up of dislocations at grain boundaries or inter...

Electromagnetic mechanism of Joule heating and thermal conduction on conductive material characterization broadens their scope for implementation in real thermography based Nondestructive testing and evaluation (NDT&E) systems by imparting sensitivity, conformability and allowing fast and imaging detection, which is necessary for efficiency. The issue of automatic material evaluation has not be...

Drilling boreholes is common practice in geotechnical and geoenvironmental investigations and in various other ex­ ploration, testing, and monitoring appli­ cations. When a casing is placed in a borehole an annular space is created be­ tween the casing and the surrounding soil. If not properly sealed, this annular space can be a potential path for trans­ port of contaminants in the subsurface e...