Optical thermography

Keywords. Enzymes, Mass spectrometry, IR-thermography, Optical detection. Fluorescence spectroscopy... 

Keywords Thermography, fibre optic, thermal anomaly, leak, natural gas, directional... 

It is also possible to partially alleviate the problem of chemical insensitivity by incorporating narrow bandpass filters into the optical setup.20 Thus, by choosing an appropriate frequency region, it becomes possible to detect the presence of a particular reactant or product species. While this adds some measure of chemical sensitivity to the thermography approach, it is only capable of monitoring one species at a time. Additionally, the success of this approach relies upon the fact that the spectral bands of the desired species do not overlap with any other species and that unexpected reaction products that have spectral contributions in the region of interest are not present. 

Methods for recognizing morphological and functional characteristics include intracoronar/ thermography, spectroscopy, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and intravascular magnetic resonance imaging (MRI). 

Other ee assays have been described, although in several cases the actual degree of throughput was not specified [10]. These systems include assays based on color tests [8,46 - 48,60], IR-thermography [49,61], circular dichroism [62], fluorescence [63], and even special forms of gas chromatography [64], Moreover, optically active compounds capable of enantioselective recognition of chiral substrates can be used as... 

Finally, we mention several current applications somewhat outside of biochemistry in the usual sense. Thermography has slowly been coming to the fore. Many of the problems associated with the analysis of thermograms were treated at the Fifth International Symposium on Temperature (Plumb, 1972) in 1972 and new applications were discussed at the Sixth Symposium (Schooley, 1982) in 1982. Of perhaps more current interest is the greatly expanded interest in temperature measurement in hyperthermia and hypothermia. A recent New York Academy of Sciences conference has done an excellent job of reviewing this (Ann. N.Y. Acad., 1980). Cetas also wrote a general review of thermometry in this field (Cetas, 1968). Perhaps the most exciting new method in thermometry is that of optical fluorescence, which we described earlier. Catheters, whole-body scanners, etc., have been made for use with this method. At this point, 0.01°C is probably the least imprecision that can be obtained with the commercial instrument (Luxtron), with data obtained every 0.1 sec. Improvements are likely, however, as needs are made known to the company. 

Infrared thermography is a very attractive method for the detection of catalytic activity 15). As it is an optical inspection , it can be applied to all kinds of libraries and screening reactions. The detection of catalytic activity is based on reaction enthalpy (negative or positive) 16). As most oxidation reactions are significantly exothermic, IR thermography lends itself very well as a sensitive tool for the discovery of oxidation catalysts (see Section II. C) 17). 

The inventions of the scanning tunnelling microscope (STM) [16] and the atomic force microscope (AFM) [17] have allowed sub-micrometre and, at times, atomic-scale spatially-resolved imaging of surfaces. Spatially-resolved temperature measurements using optical systems are diffraction limited by the wavelength of the radiation involved, which is about 5-10 pm for infrared thermography and about 0.5 pm for visible light [18]. The spatial resolution of near-field techniques (such as AFM) is only limited by the active area of the sensor (which in the case of STM may be only a few atoms at the end of a metal wire). 

The subject of liquid crystals has now grown to become an exciting interdisciplinary field of research with important practical applications. This book presents a systematic and self-contained treatment of the physics of the different types of thermotropic liquid crystals - the three classical types, nematic, cholesteric and smectic, composed of rod-shaped molecules, and the newly discovered discotic type composed of disc-shaped molecules. The coverage includes a description of the structures of these four main types and their polymorphic modifications, their thermodynamical, optical and mechanical properties and their behaviour under external fields. The basic principles underlying the major applications of liquid crystals in display technology (for example, the twisted and supertwisted nematic devices, the surface stabilized ferroelectric device, etc.) and in thermography are also discussed. 

Liquid crystals (LCs) are widely used In Informationprocessing devices, for optical visualization of physical Influences (heat, IR, high-frequency radiation, pressure, etc.), for nondestructive testing, and for thermography. 

In addition to the widely used techniques of photography, optical microscopy, SEM, thermography, topography, measurement by tools, XRD, and wet chemical analysis, there are various other techniques that can be appUed to post-test SOFC stack analysis. A few examples are given below, but this hst does not claim to be exhaustive ... 

Nondestructive Testing of Adhesive Joints. Many commercially available adhesives are based on polymers. NDT of adhesive joints (180) poses challenges because of (2) the small size of possibly deleterious defects (eg, porosity), (2) the thinness of the adhesive layers, and (3) sometimes, the size, shape, and material of the adherends. Acousto-ultrasonics (181) and various types of ultrasonics (182,183) are applicable to adhesive joints. Ultrasonics can be combined with noncontact optical methods (184) and pulsed thermography (185). However, the assessment of the quality or of the quantitative strength of the adhesive bond based on the NDT data often proves difficult. 

R. Yang, Y. He, Optieally and non-optically excited thermography for composites a review. Infr. Phy. Tech. 75, 26-50 (2016)... 

It is clear that the optical properties of a cholesteric material used for thermography... 

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