High Spatial-Resolution Digital Phase-Stepping Shearography

Digital phase-stepping shearography is a speckle interferometric technique that uses laser speckles to generate the phase map of the displacement derivatives of a stressed object, and hence can map the stresses of a deformed object directly. Conventional digital phase-stepping shearography relies on the use of video cameras of relatively lower resolution, in the order of 5 megapixels or lower, operating at a video rate. In the present work, we propose a novel method of performing high spatial resolution phase stepping shearography. This method uses a 24 megapixel still digital imaging device (DSLR camera) and a Michelson-type shearing arrangement with an edge-clamped, center-loaded plate. Different phase-stepping algorithms were used, and all successfully generated shearograms. The system enabled extremely high-resolution phase maps to be generated from relatively large deformations applied to the test plate. Quantitative comparison of the maximum achieved spatial resolution is made with the video-rate cameras used in conventional shearography. By switching from conventional (video) imaging methods to still imaging methods, significantly higher spatial resolution (by about 5 times) can be achieved in actual phase-stepping shearography, which is of great usefulness in industrial non-destructive testing (NDT).

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High spatial resolution ZnO scintillator for an in situ imaging device in EUV region

Optical Materials ◽

10.1016/j.optmat.2014.01.031 ◽

2014 ◽

Vol 36 (12) ◽

pp. 2012-2015 ◽

Cited By ~ 5

Author(s):

Ren Arita ◽

Tomoharu Nakazato ◽

Toshihiko Shimizu ◽

Kohei Yamanoi ◽

Melvin John Fernandez Empizo ◽

...

Keyword(s):

Spatial Resolution ◽

High Spatial Resolution ◽

Imaging Device ◽

In Situ Imaging

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A phase demodulation method for two-dimensional grating-based X-ray interferometry

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2013.0034 ◽

2014 ◽

Vol 372 (2010) ◽

pp. 20130034 ◽

Cited By ~ 1

Author(s):

Kentaro Nagai

Keyword(s):

Spatial Resolution ◽

High Spatial Resolution ◽

Control Process ◽

Two Dimensional ◽

X Ray ◽

Phase Stepping ◽

Novel Approach ◽

Spectral Components ◽

Demodulation Method ◽

Exposure Process

This paper presents a novel approach to achieving high spatial resolution in the demodulation of images produced by a two-dimensional X-ray Talbot interferometry (XTI) system. Currently, demodulation of XTI images is mainly performed by either phase-stepping (PS) or Fourier transform (FT) methods. However, the PS method for two-dimensional XTI demodulation requires a larger number of exposures and a more complex grating control process than that of one-dimensional XTI. On the other hand, although the FT method uses only a single-fringe image, it gives lower spatial resolution than the PS method. For practical application of two-dimensional XTI, a simpler exposure process with high spatial resolution is required. In this paper, we introduce a hybrid method combining the PS and FT methods. This method simplifies the exposure process in comparison with the PS method required in two-dimensional XTI while achieving higher spatial resolution than the FT method in the demodulation of images. The method works by using additional exposures to eliminate unnecessary spectral components that appear in the FT method. Furthermore, the proposed method is demonstrated by using actual two-dimensional XTI data and shown to achieve high spatial resolution in the demodulation of images for both the x - and y -differential phase components.

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The Infrared Granulation: Observations

Symposium - International Astronomical Union ◽

10.1017/s0074180900124489 ◽

1994 ◽

Vol 154 ◽

pp. 239-250

Author(s):

Serge Koutchmy

Keyword(s):

Power Spectrum ◽

Spatial Resolution ◽

Large Scale ◽

High Spatial Resolution ◽

Temperature Fluctuations ◽

Histogram Analysis ◽

Solar Granulation ◽

Imaging Methods ◽

Lifetime Analysis ◽

Analysis Center

High spatial resolution observations of the solar granulation up to 3 μm are possible on existing vacuum solar telescopes. They permit the analysis of the deepest photospheric layers near 1.7 μm. A high photometric accuracy is achieved using scanning techniques with a pinhole photometer; imaging methods are used for 2D-analysis. Statistically significant results on granulation, including power spectrum and histogram analysis, center-limb variations and lifetime analysis, are presented. Temperature fluctuations of periods near 5 minute are considered at 1.7 μm, as well as large-scale variations at the scale of the meso- and, especially, the super-granulation. We also discuss the “abnormal” granulation in magnetic regions and the umbral granulation in the cores of sunspots.

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High spatial resolution AEM observations of yttrium segregation in chromia scales grown on Co-45%Cr

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144103 ◽

1986 ◽

Vol 44 ◽

pp. 518-519

Author(s):

K. Przybylski ◽

A. J. Garratt-Reed ◽

G. J. Yurek

Keyword(s):

Spatial Resolution ◽

Outer Surface ◽

Maximum Concentration ◽

High Spatial Resolution ◽

Reactive Elements ◽

Chromia Scales

The addition of so-called “reactive” elements such as yttrium to alloys is known to enhance the protective nature of Cr2O3 or Al2O3 scales. However, the mechanism by which this enhancement is achieved remains unclear. An A.E.M. study has been performed of scales grown at 1000°C for 25 hr. in pure O2 on Co-45%Cr implanted at 70 keV with 2x1016 atoms/cm2 of yttrium. In the unoxidized alloys it was calculated that the maximum concentration of Y was 13.9 wt% at a depth of about 17 nm. SIMS results showed that in the scale the yttrium remained near the outer surface.

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Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016323x ◽

1996 ◽

Vol 54 ◽

pp. 154-155

Author(s):

E. G. Rightor

Keyword(s):

Excited State ◽

Polymer Blends ◽

Gas Phase ◽

Spatial Resolution ◽

High Spatial Resolution ◽

Electronic States ◽

Core Electron ◽

Bulk Solids ◽

Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

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