Terahertz (THz) radiation has been widely applied in the areas of spectroscopy, sensing and imaging. With the advancement of THz technologies, THz imaging has been progressed significantly and has huge potential appli...
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(纸本)9780819488367
Terahertz (THz) radiation has been widely applied in the areas of spectroscopy, sensing and imaging. With the advancement of THz technologies, THz imaging has been progressed significantly and has huge potential applications in medical diagnosis, environmental control, chemical and biological identification. In the past, people mainly focused on overcoming the obstacles in the hardware, such as the limitation of resolution, accuracy and speed in THz imaging system. In this paper, image enhancement techniques are employed to enhance the contrast and get the better profile of THz image. Our results clearly demonstrate that digital image processing techniques can suppress noise effectively, extract target edges robustly, and therefore improve the quality of THz image.
Motionless mixers have found a large range of applications, including blending, reaction, dispersion, heat transfer and mass transfer. Understanding the mixing processes that occur in these diverse systems is essentia...
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Motionless mixers have found a large range of applications, including blending, reaction, dispersion, heat transfer and mass transfer. Understanding the mixing processes that occur in these diverse systems is essential for predicting many aspects of practical importance. The objective of this study is to perform the experimental investigations of mixing characteristics for three different motionless mixers. The red color dye tracer was mixed in the main stream of green hair styling gel, and then the mixing efficiency was quantified by calculating the percentage area concentration of red color at the outlet cross section using a digital image processing technique. In the Sulzer SMX and YHC mixer, a single element mixes the fluid nearly in two dimensions, and three-dimensional mixing is accomplished by the next elements aligned at 900 to their former one. In the Sulzer SMX mixer, the flow appears to be globally well mixed after 5 elements, while in the YHC and YNU mixers, it is necessary to globally well mix more than 1 and 2 elements.
The shadow moire technique, which is a straightforward method for contactless non-destructive metrological measurements associated with digitalimageprocessing, was used to erect a micro-movement measurement system a...
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The shadow moire technique, which is a straightforward method for contactless non-destructive metrological measurements associated with digitalimageprocessing, was used to erect a micro-movement measurement system and to design a dilatometer. By adjusting the angle of inclination of the reference grating and the angle of incident light, the sensitivity of the measurement system could be controlled. A piezoelectric material with nanometer precision was used to calibrate the measurement system. The moire interference fringes grabbed by a CCD camera were obtained and then input into the computer, in which the digital image processing technique was employed to improve the resolution of the fringes dramatically. The results revealed that one could measure the micro-movement accurately with a slight error of about 4% using the present set-up. A dilatometer equipped with the above-mentioned measurement system was established. By comparing the thermal expansion of the specimen with the reference material, the thermal expansion coefficient of the specimen can be determined precisely, which agrees well with the literature values.
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