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Radiation Properties of Surfaces
Published in E. M. Sparrow, R. D. Cess, Radiation Heat Transfer, 2018
The theoretical results discussed so far were derived for optically smooth surfaces. Practical engineering surfaces rarely achieve this degree of smoothness. Various authors have pursued the extension of classical electromagnetic theory in an effort to account for surface roughness. Two basic approaches have been employed. The first involves the application of diffraction theory to a statistically rough surface, while the second seeks the solution of Maxwell’s equations corresponding to highly complex boundary conditions. These approaches are exemplified respectively by the papers of Davies (ref. 28) and of Rice (ref. 29). Furthermore, recent analytical contributions have been reviewed in a comprehensive text by Beckmann and Spizzichino (ref. 30).
Three-Dimensional Vision
Published in Richard L. Shell, Ernest L. Hall, Handbook of Industrial Automation, 2000
Other three-dimensional techniques are tailored to specific applications. Interferometry techniques can be used to determine surface smoothness. It is frequently used in ultrahigh precision applications that require accuracies up to the wavelength of light. Specialized medical imaging systems such as magnetic resonance imaging (MRI) or ultrasound also acquire three-dimensional data by penetrating the subject of interest. The word “vision” usually refers to an outer shell measurement, putting these medical systems outside the scope of this chapter.
Introduction
Published in R. Balasubramaniam, RamaGopal V. Sarepaka, Sathyan Subbiah, Diamond Turn Machining, 2017
R. Balasubramaniam, RamaGopal V. Sarepaka, Sathyan Subbiah
Hence, there is a need to go beyond conventional machining processes and look for drastic changes holistically, in all aspects of machining so that the requirement of surface smoothness can be addressed effectively. This leads us to the new process of diamond turn machining (DTM).
High-temperature oxidation behaviour of SPS-prepared Mo and Mo–5Ta alloys
Published in Philosophical Magazine Letters, 2022
Dawei Liu, Jiuxing Zhang, Lei Huang, Song Li, Binrong Nong, Ying Jin, Yafei Pan
The surface roughness is an important indicator for measuring the smoothness and uniformity of the surface [23,24]. As seen in Figure 5a, the surface roughness of Mo and Mo–5Ta is positively related to oxidation temperature, which is stable under 500°C and increases significantly at higher temperature. The reason for the higher surface roughness of Mo–5Ta may be the volume expansion of Ta2O5 with a higher Pilling-Bedworth ratio (PBR) after being oxidised [25].