Imaging spectrum

Figure 6. Schematic illustrating the effect of hnear (blue) and selected non-linear (red) contributions to the image spectrum.

Figure 3.19. A single-channel detection scheme is unable to differentiate positive and negative frequencies in the rotating frame. This results in a mirror image spectrum being superimposed on the true one if the transmitter is placed in the centre of the spectrum.

EFTEM by EELS in me image-spectrum mode was used in several applications to polymeric materials such as me following ... 

Fig. 4 Image, spectrum and calculated elemental concentrations (%w) for two particles (a) aged sea salt (b) sea salt.

Taylor PC, Steuer A, Gruber J et al (2004) Comparison of ultrasonographic assessment of synovitis and joint vascularity with radiographic evaluation in a randomized, placebo-controlled study of infliximab therapy in early rheumatoid arthritis. Arthitis Rheum 50 1107-1116 Terslev L, Qvistgaard E, Torp-Pedersen S et al (2001) Ultrasound and power Doppler findings in jumper s knee preliminary observations. Eur J Ultrasound 13 183-189 Torreggiani WC, Al-Ismail K, Munk PL et al (2002) The imaging spectrum of Baker s (Popliteal) cysts. Clin Radiol 57 681-691... 

The detectability of critical defects with CT depends on the final image quality and the skill of the operator, see figure 2. The basic concepts of image quality are resolution, contrast, and noise. Image quality are generally described by the signal-to-noise ratio SNR), the modulation transfer function (MTF) and the noise power spectrum (NFS). SNR is the quotient of a signal and its variance, MTF describes the contrast as a function of spatial frequency and NFS in turn describes the noise power at various spatial frequencies [1, 3]. 

From where the idea to do a processing of the image received by this spectrum to identify this defect. 

An experimental teclmique that is usefiil for structure studies of biological macromolecules and other crystals with large unit cells uses neither the broad, white , spectrum characteristic of Lane methods nor a sharp, monocliromatic spectrum, but rather a spectral band with AX/X 20%. Because of its relation to the Lane method, this teclmique is called quasi-Laue. It was believed for many years diat the Lane method was not usefiil for structure studies because reflections of different orders would be superposed on the same point of a film or an image plate. It was realized recently, however, that, if there is a definite minimum wavelengdi in the spectral band, more than 80% of all reflections would contain only a single order. Quasi-Laue methods are now used with both neutrons and x-rays, particularly x-rays from synclirotron sources, which give an intense, white spectrum. 

The molecular structures were rendered with good-quality shading on a blue background. Isosurfaces produced from cube files or checkpoint files also looked nice. Molecular vibrations can be animated on screen and vibrational displacement vectors displayed. The vibrational line spectrum may be displayed too, but the user has no control over the axes. There is no way to set the background color. The display can be saved using several image file formats. 

Figure 2 Micrographs of the same region of a specimen in various imaging modes on a high-resolution SEM (a) and (b) SE micrographs taken at 25 and 5 keV, respectively (c) backscattered image taken at 25 keV (d) EDS spectrum taken from the Pb-rich phase of the Pb-Sn solder (e) and (f) elemental maps of the two elements taken by accepting only signals from the appropriate spectral energy regions.

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