Motion of crystalline inclusions by interface diffusion in the proximity of free surfaces

INTRODUCTION.- The physical properties of rock masses are greatly influenced by their internal discontinuities, like pores and fissures. So, these need to be measured as a basis for interpretation. To avoid the basic difficulties of measurement under optical microscopy and analogic image systems, the authors use S.E.M. and multiband digital image processing. In S.E.M., analog signal processing has been used to further image enhancement (1), but automatic information extraction can be achieved by simple digital processing of S.E.M. images (2). The use of multiband image would overcome difficulties such as artifacts introduced by the relative positions of sample and detector or the typicals encountered in optical microscopy.DIGITAL IMAGE PROCESSING.- The studied rock specimens were in the form of flat deformation-free surfaces observed under a Phillips SEM model 500. The SEM detector output signal was recorded in picture form in b&w negatives and digitized using a Perkin Elmer 1010 MP flat microdensitometer.

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Attractive mode force microscopy of chiral liquid crystal surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121740 ◽

1992 ◽

Vol 50 (1) ◽

pp. 268-269

Author(s):

B.D. Terris ◽

R. J. Twieg ◽

C. Nguyen ◽

G. Sigaud ◽

H. T. Nguyen

Keyword(s):

Liquid Crystal ◽

Crystal Surfaces ◽

Free Surfaces ◽

Control Range ◽

Force Microscopy ◽

Liquid Crystal Films ◽

Chiral Liquid Crystal ◽

Crystal Films ◽

Electrostatic Charging ◽

And Shifts

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.

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Mean-field analytical calculation of the segregation profile around grain boundaries and free surfaces in binary alloys

Philosophical Magazine A ◽

10.1080/014186100300012607 ◽

2000 ◽

Vol 80 (12) ◽

pp. 2871-2897

Author(s):

I. P. Antoniades, G. L. Bleris

Keyword(s):

Grain Boundaries ◽

Binary Alloys ◽

Mean Field ◽

Analytical Calculation ◽

Free Surfaces ◽

Segregation Profile

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Improving the Organic Semiconductor- Metal Contact Interface in Printed High Performance Organic TFTs

MRS Proceedings ◽

10.1557/opl.2012.189 ◽

2012 ◽

Vol 1402 ◽

Author(s):

Kanan Puntambekar ◽

Lisa Stecker ◽

Kurt Ulmer ◽

Themistokles Afentakis ◽

Steven Droes

Keyword(s):

Organic Semiconductor ◽

High Performance ◽

Thin Film Transistor ◽

Device Performance ◽

Organic Thin Film ◽

Contact Interface ◽

Organic Thin Film Transistor ◽

Metal Electrodes ◽

Free Surfaces ◽

Gas Plasma

ABSTRACTOptimization of the interface between the organic semiconductor (OSC) & the source-drain (S/D) electrode is critical in order to improve organic thin film transistor (OTFT) device performance. This process typically involves coating the metal S/D electrodes with an optimal self-assembled thiol layer; a process that requires pristine metal surfaces for successful treatment. Obtaining contamination free surfaces can be challenging in the case of printed metal electrodes. Here we demonstrate an effective strategy to address this issue by introducing a brief low power forming gas plasma treatment prior to the surface coating step. We show a two orders of magnitude decrease in the contact resistance as a result of this treatment.

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Start of the Green Season and Normalized Difference Vegetation Index in Alaska’s Arctic National Parks

Remote Sensing ◽

10.3390/rs13132554 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2554

Author(s):

David K. Swanson

Keyword(s):

National Parks ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Free Surfaces ◽

Modis Ndvi ◽

Curve Fit ◽

Winter Snow ◽

Systematic Sample ◽

Low Levels ◽

Northern Alaska

Daily Normalized Difference Vegetation Index (NDVI) values from the MODIS Aqua and Terra satellites were compared with on-the-ground camera observations at five locations in northern Alaska. Over half of the spring rise in NDVI was due to the transition from the snow-covered landscape to the snow-free surface prior to the deciduous leaf-out. In the fall after the green season, NDVI fluctuated between an intermediate level representing senesced vegetation and lower values representing clouds and intermittent snow, and then dropped to constant low levels after establishment of the permanent winter snow cover. The NDVI value of snow-free surfaces after fall leaf senescence was estimated from multi-year data using a 90th percentile smoothing spline curve fit to a plot of daily NDVI values vs. ordinal date. This curve typically showed a flat region of intermediate NDVI values in the fall that represent cloud- and snow-free days with senesced vegetation. This “fall plateau” was readily identified in a large systematic sample of MODIS NDVI values across the study area, in typical tundra, shrub, and boreal forest environments. The NDVI level of the fall plateau can be extrapolated to the spring rising leg of the annual NDVI curve to approximate the true start of green season.

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