Vignetting correction by exploiting an optical microscopy image sequence

2011 ◽  
Author(s):  
A. Bevilacqua ◽  
F. Piccinini ◽  
A. Gherardi
Keyword(s):  
Optical Microscopy ◽  
Image Sequence ◽  
Microscopy Image ◽  
Optical Microscopy Image

Temperature dependence of the pitch in chiral lyotropic chromonic liquid crystals

Soft Matter ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Timothy Ogolla ◽  
Robert S. Paley ◽  
Peter J. Collings
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Temperature Dependence ◽  
Optical Microscopy ◽  
Helical Axis ◽  
Coexistence Region ◽  
Polarized Optical Microscopy ◽  
Chiral Nematic ◽  
Microscopy Image ◽  
Optical Microscopy Image

Polarized optical microscopy image of a fingerprint texture for a lyotropic chromonic liquid crystal entering the chiral nematic–isotropic coexistence region. The helical axis is in the plane of the image and the perpendicular distance between the stripes is around 50 μm, half the chiral nematic pitch.

scholarly journals Effect of fly ash particle reinfo rcement on microstructure, porosity and hardness in Al-(Si-Mg) cast composites

2017 ◽  
Vol 23 (1&2) ◽  
pp. 113 ◽  
Author(s):  
M.B. Harun ◽  
S.R. Shamsudin ◽  
H. Yazid ◽  
Z. Selamat ◽  
M.S. Sattar ◽  
...  
Keyword(s):  
Fly Ash ◽  
Casting Process ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Image Analyzer ◽  
Microscopy Image ◽  
Optical Microscopy Image ◽  
Cast Composites ◽  
The Matrix ◽  
Scanning Electron

The microstructure of cast Al-4Si-Mg reinforcedwith fly ash particles at various particlecontents has been studied. The composites were fabricated by stir casting process andcharacterized by optical microscopy, image analyzer, scanning electron microscopy and hardness measurements. The results showed that particle contents affected to the presence oforosities and hardness of the composites. It was observed that increasing the fly ash contentincrease the porosity in the composites, with the matrix alloy reinforced with 15 wt.% of fly ash particles having the highest porosity and lowest hardness.

Algorithms for Extraction of Nanowire Lengths and Positions From Optical Section Microscopy Image Sequence

2009 ◽  
Vol 9 (4) ◽  
Author(s):  
Tao Peng ◽  
Arvind Balijepalli ◽  
Satyandra K. Gupta ◽  
Thomas W. LeBrun
Keyword(s):  
Image Processing ◽  
Optical Tweezers ◽  
Image Sequence ◽  
Optical Section ◽  
Image Frame ◽  
Image Processing Techniques ◽  
Microscopy Image ◽  
Processing Techniques ◽  
Areas Of Interest ◽  
Microscopy Images

This paper presents algorithms for estimating length, location, and orientation of nanowires in a fluidic workspace using images obtained by optical section microscopy. Images containing multiple nanowires are first segmented to locate general areas of interest, which are then analyzed to determine discrete nanowire parameters. We use a set of image processing techniques to extract features of nanowire image patterns, e.g., boundary of nanowire, linear edges, and the intensity profile of nanowire’s diffraction fringes. The parameters of the features are then used to estimate length, 3D position, and 3D orientation of nanowires. A scene representing the workspace is reconstructed using the estimated attributes of nanowires, and it is constantly updated upon the capture of every image frame. We believe that the work described in this paper will be useful for assembly of nanowires using optical tweezers.

The Porous TiNb24Zr4 Alloys with Controllable Porosity Fabricated by Conventional Sintering

2011 ◽  
Vol 335-336 ◽  
pp. 797-804
Author(s):  
Yu Xuan Li ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
Sheng Li Zhu
Keyword(s):  
Titanium Alloys ◽  
Porous Titanium ◽  
Ammonium Bicarbonate ◽  
Pore Characteristics ◽  
Β Phase ◽  
Α Phase ◽  
Microscopy Image ◽  
Optical Microscopy Image ◽  
Conventional Sintering ◽  
Sintering Method

In the present study, porous titanium alloys were fabricated successfully by mixing titanium, niobium, and zirconium powder with pore-forming agent of ammonium bicarbonate via conventional sintering method. The pore characteristics, such as pore morphology and distribution, mean pore size and porosity of prepared porous TiNb24Zr4alloy were investigated by optical microscopy, image processing and density determination. It was found that the pore characteristics mainly depended on the shape and size of used ammonium bicarbonate particles in present study. The porosity of the alloys could be tailored by controlling the amount of ammonium bicarbonate addition. The porous TiNb24Zr4alloys were near β type titanium alloys, which consisted mainly of β phase and a little of α phase. The amount of α phase increased in the porous alloys due to segregation caused by the addition of pore-forming agent.

Microstructural Characterisation of Microwave Sintered Silicon Nitride Ceramics

1992 ◽  
Vol 287 ◽  
Author(s):  
Kevin P. Plucknett ◽  
David S. Wilkinson
Keyword(s):  
Silicon Nitride ◽  
Heat Dissipation ◽  
Hot Isostatic Pressing ◽  
Analytical Electron Microscopy ◽  
Porosity Level ◽  
Microscopy Image ◽  
Optical Microscopy Image ◽  
Nitride Ceramics ◽  
Microstructural Characterisation ◽  
Sintered Silicon

The microstructure of a series of microwave sintered silicon nitride based ceramics have been assessed using a combination of optical microscopy/image analysis and analytical electron microscopy. Materials were studied as-received and after post-sinter hot-isostatic pressing. The grain size of microwave sintered materials was appreciably finer than conventionally processed ceramics of similar composition, although the mechanism involved is not clear. The as-received ceramics exhibited a reverse porosity gradient (with the highest porosity level at the surface) due to heat dissipation to the cooler surroundings during sintering. This also resulted in a small increase in the β′ grain aspect ratio close to the surface arising from an increase in the glass phase viscosity as the temperature decreases. Post-sinter HIPing of microwave sintered samples resulted in the elimination of most of the bulk porosity, but not near the surface. This is due to the reverse porosity gradient previously described, which leads to a transition from closed to open porosity with decreasing density near to the surface.

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