From Nylonkong to Haiwankong: an imagination

The recent developments have shown the advantages of the thermographic technique for the detection of corrosion and disbonds in aircraft structures[l–3]. These have typically involved the application of heat with an infrared source and imaging the induced temperature change with an infrared imager. This offers a rapid method for detecting corrosion and quantifying its extent in single layer structures. In these application, the heating and imaging components of the system remain stationary during the measurement cycle. Two disadvantages of this technique are the expense of the infrared imager and the large power requirement for the infrared heater

The Intra-Asian Networks: Japan and Hong Kong in the Nineteenth-Century

Thermal Nondestructive Testing (TNDT) is an increasingly common technique for detecting delaminations in structures[l–7]. Typically, TNDT uses radiative heaters such as flash or quartz lamps to heat the specimen. Before during and after radiative heating, an infrared imager measures the surface temperature. Since this process is a noncontacting and imaging method, it has several advantages over conventional contacting techniques. It is able to rapidly inspect a square meter of structure in minutes. It also is easy to inspect curve surfaces. A principle disadvantage is its lack of sensitivity to delaminations at depths greater than 1/2 the thickness of the structure

Basalt fibre laminates non-destructively inspected after low velocity impacts

In this work, the use of advanced thermographic techniques for the post-impact defect detection in basalt fibre reinforced composite laminates was investigated. The laminates were previously impacted at different energies, namely 7.5, 15 and 22.5 J and then subjected to accelerated environmental aging or to a coating process in order to conceal the previous damage due to low velocity impact. In both cases the defects could be identified using infrared thermography in the mid-wave infrared (MWIR) spectrum even after the treatments. In addition, short-wave infrared (SWIR) results were employed with the aim to clearly identify unsuspected resin-rich areas. Therefore, the non-thermal part of the infrared spectrum (SWIR) can be coupled with the thermal part (MWIR) providing a complete infrared vision beyond what is perceptible to the naked eye, i.e., in the visible spectrum

The vascular basis of the temporalis muscle flap in maxillofacial reconstruction

Cost effective bridge deck rehabilitation makes it necessary to locate the areas in need of repair to accurately estimate the quantity of deteriorated concrete. Since the bituminous overlay prevents visual identification of these areas, nondestructive testing and evaluation techniques are essential [1]. Conventional nondestructive testing techniques, such as sounding by hammer and chain drag, do not fare well on asphalt covered decks, primarily due to the inefficient coupling of energy between the asphalt overlay and the concrete. They are usually effective only after the asphalt overlay has been removed [2]. Destructive testing methods such as core samples are effective when a large number of random samples are obtained, which is both costly and unnecessarily damaging to the bridge deck. Recently, nondestructive testing and evaluation techniques, such as impact-echo [3–9], ground penetrating radar [10–17], and infrared thermography [18–23], have shown promise for the noninvasive evaluation of the damage accumulation in concrete bridge decks overlaid with asphalt concrete wearing surfaces. Each nondestructive evaluation method has its own current advantages and limitations which are presented and discussed in this study