Color mapping of polarized polychromatic beam passing through birefringent medium

2001 ◽  
Author(s):  
Biswajit Chakraborty
Keyword(s):  
Color Mapping ◽  
Polychromatic Beam ◽  
Birefringent Medium

Depolarization of polarized polychromatic beam during propagation in a birefringent medium

Optik ◽  
2016 ◽  
Vol 127 (15) ◽  
pp. 5882-5886
Author(s):  
Arijit Saha ◽  
Kallol Bhattacharya ◽  
Ajoy Kumar Chakraborty
Keyword(s):  
Polychromatic Beam ◽  
Birefringent Medium

scholarly journals Coronary Flow and Reserve by Enhanced Transthoracic Doppler Trumps Coronary Anatomy by Computed Tomography in Assessing Coronary Artery Stenosis

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 245
Author(s):  
Carlo Caiati ◽  
Arnaldo Scardapane ◽  
Fortunato Iacovelli ◽  
Paolo Pollice ◽  
Teresa Immacolata Achille ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Flow Velocity ◽  
Coronary Flow ◽  
Invasive Coronary Angiography ◽  
Coronary Anatomy ◽  
Color Mapping ◽  
Flow Reserve ◽  
Mild Stenosis ◽  
Iodinated Contrast

We report the case of a 71-year-old patient with many risk factors for coronary atherosclerosis, who underwent computed coronary angiography (CTA), in accordance with the guidelines, for recent onset atypical chest pain. CTA revealed critical (>50% lumen diameter narrowing) stenosis of the proximal anterior descending coronary, and the patient was scheduled for invasive coronary angiography (ICA). Before ICA he underwent enhanced transthoracic echo-Doppler (E-Doppler TTE) for coronary flow detection by color-guided pulsed-wave Doppler recording of the left main (LMCA) and whole left anterior descending coronary artery (LAD,) along with coronary flow reserve (CFR) in the distal LAD calculated as the ratio, of peak flow velocity during i.v. adenosine (140 mcg/Kg/m) to resting flow velocity. E-Doppler TTE mapping revealed only mild stenosis (28% area narrowing) of the mid LAD and a CFR of 3.20, in perfect agreement with the color mapping showing no flow limiting stenosis in the LMCA and LAD. ICA revealed only a very mild stenosis in the mid LAD and mild atherosclerosis in the other coronaries (intimal irregularities). Thus, coronary stenosis was better predicted by E-Doppler TTE than by CTA. Coronary flow and reserve as assessed by E-Doppler TTE trumps coronary anatomy as assessed by CTA, without exposing the patient to harmful radiation and iodinated contrast medium.

scholarly journals One-shot BRDF imaging system to obtain surface properties

2021 ◽  
Author(s):  
Hiroshi Ohno ◽  
Takahiro Kamikawa
Keyword(s):  
Surface Properties ◽  
Imaging System ◽  
Reconstruction Method ◽  
Surface Reflectance ◽  
Bidirectional Reflectance Distribution Function ◽  
Bidirectional Reflectance ◽  
Color Mapping ◽  
System A ◽  
Cone Surface ◽  
Bidirectional Reflectance Distribution

AbstractThe bidirectional reflectance distribution function (BRDF) that describes an angle-resolved distribution of surface reflectance is available for characterizing surface properties of a material. A one-shot BRDF imaging system can capture an in-plane color mapping of light direction extracted from a surface BRDF distribution. A surface roughness identification method is then proposed here using the imaging system. A difference between surface properties of a matt paper and a glossy paper is experimentally shown to be detected using the method. A surface reconstruction method of an axisymmetric micro-object using the imaging system is also proposed here. The imaging system experimentally shows that it can reconstruct an axisymmetric aluminium cone surface with a height of 37 μm.

An elastically bent silicon crystal as a monochromator for thermal neutrons

1990 ◽  
Vol 23 (2) ◽  
pp. 105-110 ◽  
Author(s):  
P. Mikula ◽  
E. Krüger ◽  
R. Scherm ◽  
V. Wagner
Keyword(s):  
Momentum Space ◽  
Pyrolytic Graphite ◽  
Silicon Crystal ◽  
Thermal Neutrons ◽  
Monochromatic Beam ◽  
Beam Density ◽  
Diffraction Geometry ◽  
Bending Radius ◽  
Neutron Monochromator ◽  
Polychromatic Beam

Some experimental results are presented for an elastically bent perfect silicon crystal in a strongly asymmetric diffraction geometry as a neutron monochromator. The use of this unconventional geometry of the monochromator appears to be suitable for a wide (several centimetres) incident polychromatic beam, when, thanks to the spatial condensation of the diffracted neutrons (Fankuchen effect), a high monochromatic beam density may be obtained. Furthermore, when using focusing in real and in momentum space by adjusting an optimum bending radius, the intensity diffracted by a sample may be comparable even with the best mosaic monochromators such as highly oriented pyrolytic graphite (PG). A comparison is demonstrated on the rocking curves of a strongly mosaic Ni–Al(020) crystal obtained with the monochromatic beam from bent Si(111), Si(400) and from PG(002), Cu(220) mosaic monochromators.

MR Color Mapping of Myelin Fiber Orientation

1991 ◽  
Vol 15 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Philippe Douek ◽  
Robert Turner ◽  
James Pekar ◽  
Nichoias Patronas ◽  
Denis Le Bihan
Keyword(s):  
Fiber Orientation ◽  
Color Mapping
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