Application of image analysis to the measurement of particle size and shape. Use of automatic image analysis in the assessment of particle and grain size distributions

1984 ◽  
Vol 21 (12) ◽  
pp. 506 ◽  
Author(s):  
Brian Ralph
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Image Analysis ◽  
Size Distributions ◽  
Automatic Image Analysis ◽  
Size And Shape ◽  
Grain Size Distributions ◽  
Particle Size And Shape

scholarly journals Influence of grain growth on the thermal structure of protoplanetary discs

2020 ◽  
Vol 640 ◽  
pp. A63 ◽  
Author(s):  
Sofia Savvidou ◽  
Bertram Bitsch ◽  
Michiel Lambrechts
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Grain Growth ◽  
Thermal Structure ◽  
Size Composition ◽  
Size Distributions ◽  
Migration Rates ◽  
Grain Size Distributions ◽  
Hydrodynamical Simulations ◽  
Protoplanetary Discs

The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, for example, by considering only a single particle size. In the present work, we perform 2D hydrodynamical simulations of protoplanetary discs where the opacity is self-consistently calculated for the dust population, taking into account the particle size, composition, and abundance. We first compared simulations utilizing single grain sizes to two different multi-grain size distributions at different levels of turbulence strengths, parameterized through the α-viscosity, and different gas surface densities. Assuming a single dust size leads to inaccurate calculations of the thermal structure of discs, because the grain size dominating the opacity increases with orbital radius. Overall the two grain size distributions, one limited by fragmentation only and the other determined from a more complete fragmentation-coagulation equilibrium, give comparable results for the thermal structure. We find that both grain size distributions give less steep opacity gradients that result in less steep aspect ratio gradients, in comparison to discs with only micrometer-sized dust. Moreover, in the discs with a grain size distribution, the innermost (<5 AU) outward migration region is removed and planets embedded in such discs experience lower migration rates. We also investigated the dependency of the water iceline position on the alpha-viscosity (α), the initial gas surface density (Σg,0) at 1 AU and the dust-to-gas ratio (fDG) and find rice ∝ α0.61Σg,00.8fDG0.37 independently of the distribution used in the disc. The inclusion of the feedback loop between grain growth, opacities, and disc thermodynamics allows for more self-consistent simulations of accretion discs and planet formation.

Effect of Electron Microscope Magnification on the Determination of Particle Size and Shape by Image Analysis

2007 ◽  
Vol 121-123 ◽  
pp. 893-896
Author(s):  
Zheng Min Li
Keyword(s):  
Particle Size ◽  
Image Analysis ◽  
Standard Sample ◽  
Standard Specimen ◽  
Particle Diameter ◽  
Value Change ◽  
Size And Shape ◽  
Transmission Electron ◽  
Particle Size And Shape

To investigate the effect of magnification (M) on determination of particle size and shape by transmission electron microscopy (TEM) and image analysis. The calibration curve and its simulative equation of TEM magnification are obtained by measurement of a grating replica standard specimen at different magnifications. Based on the analysis of TEM images at a series of magnifications for a 350nm-sphere standard sample, It has been found that the two errors of its size measurement, caused by one pixel change of the pixel number per particle diameter (Np) and by one gray value change during thresholding, is smaller, and the shape of ‘circle’ particles are close to the standard one, while Np is larger than 35. It can be seen that the suitable TEM magnification is in inverse proportion to particle size and it can be calculated by given equation.

Dextran-induced modifications of calcium carbonate particles precipitated during carbonatation

2019 ◽  
pp. 382-391
Author(s):  
Karin Abraham ◽  
Liza Splett ◽  
Eckhard Flöter
Keyword(s):  
Particle Size ◽  
Image Analysis ◽  
Calcium Carbonate ◽  
Filter Cake ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Shape Parameters ◽  
Size And Shape ◽  
Static Image ◽  
Particle Size And Shape

The effects of high and low molecular mass dextran (T2000 and T40) on the size and shape of particles precipitated during carbonatation and their correlation with filtration performances were key to this study. Varying contents of T2000 and T40 dextran in sugar solutions corresponding to DS contents of thin juice were investigated. For particle size and shape analysis, static image analysis and laser particle size analysis were used. Both methods, static image analysis and laser diffraction, revealed that the presence of T2000 and T40 dextran leads to a higher amount of large-sized particles at the expense of small-sized particles, indicating pronounced agglomeration. The additional evaluation of shape parameters (circularity, roundness, solidity) obtained from static image analysis indicates that the agglomeration is oriented in the absence and in the presence of lower T40 dextran levels. Besides, non-oriented agglomeration, resulting in more round agglomerates with smoother surfaces, was found for samples loaded with T2000 dextran and high T40 dextran levels. Only the latter samples have shown to negatively affect the filtration performance. Thus, in the presence of T2000 dextran and high T40 dextran levels, the filtration was hampered. This appears to be mainly caused by a tighter packing of more round calcium carbonate agglomerates in the porous structure of the filter cake.

scholarly journals An Experimental Study on the Particle Size and Shape Distribution of Coal Drill Cuttings by Dynamic Image Analysis

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhigang Zhang ◽  
Xiangyun Lan ◽  
Guangcai Wen ◽  
Qingming Long ◽  
Xuelin Yang
Keyword(s):  
Particle Size ◽  
Image Analysis ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Logarithmic Scale ◽  
Shape Distribution ◽  
Dynamic Image ◽  
Size And Shape ◽  
Dynamic Image Analysis ◽  
Particle Size And Shape

Particle size and shape distribution can be measured in great detail by dynamic image analysis (DIA). The narrow dispersion of repeated experiment results indicates that the particle size distribution can be obtained with high reliability. Particle size distribution can be better fitted to Rosin-Rammler equation than Gaudin-Schuhmann distribution and the lognormal distribution. The spread parameter ( m ) and the location parameters ( d 0 ) of the Rosin-Rammler equation can be calculated precisely. We analyzed the similarities and differences between the different particle shape distributions. The distributions of form factor and circularity are right-skewed distributions, while the distributions of ellipse ratio, irregularity, and aspect ratio obey a normal distribution. By studying the relation between particle size and shape, we find a linear relationship between the ellipse ratio and the Legendre ellipse diameter on the logarithmic scale.

scholarly journals Image analysis framework with focus evaluation for in situ characterisation of particle size and shape attributes

2018 ◽  
Vol 191 ◽  
pp. 208-231 ◽  
Author(s):  
Javier Cardona ◽  
Carla Ferreira ◽  
John McGinty ◽  
Andrew Hamilton ◽  
Okpeafoh S. Agimelen ◽  
...  
Keyword(s):  
Particle Size ◽  
Image Analysis ◽  
Analysis Framework ◽  
Size And Shape ◽  
Particle Size And Shape

Soil Particle Size Analysis Using X-Ray Absorption

1996 ◽  
Vol 1548 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Stanley J. Vitton ◽  
Carl C. Nesbitt ◽  
Leon Y. Sadler
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Range ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Size Distributions ◽  
X Ray ◽  
Grain Size Distributions ◽  
X Ray Absorption ◽  
Representative Samples

The hydrometer method is the standard method of grain size analysis used in geotechnical engineering. Although the hydrometer method provides accurate grain size distributions and is relatively easy to conduct, it takes a minimum of 2 days to complete and is subject to operator error. In studies where small-magnitude changes or more rapid results are required, an alternative method to hydrometer testing is to use an automated particle size analysis instrument employing X-ray absorption. This technique passes a finely collated X-ray beam through a suspension of settling particle in a fluid. Because the intensity of the X-ray is directly related to the percentage mass of soil in a suspension, Stokes' law can be used to calculate the grain size distribution of a soil assuming an equivalent particle diameter for the soil grains. X-ray absorption has been found to produce accurate grain size distributions in the 75 μm to 1 μm size range when sample preparation adheres to AASHTO T88-90 specifications and suspension concentrations are approximately 2 percent by volume. Testing for particles sizes down to 1 μm takes approximately 20 min per sample. Technical concerns remaining involve obtaining representative samples of the soil in the 75 μm, to 1 μm size range suspension for testing. One method being evaluated is injection flow analysis, which is an inexpensive method of obtaining representative samples used with a variety of inorganic, industrial, and environmental materials in which direct sampling of fluid is required.

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