scholarly journals Study on the particle shape of soft clay in Tianjin port

2019 ◽  
Vol 136 ◽  
pp. 03007
Author(s):  
Xuekui Wang ◽  
Dongjun Li ◽  
Yaoting Zhu
Keyword(s):  
Aspect Ratio ◽  
Soil Sample ◽  
Particle Shape ◽  
Soft Clay ◽  
Microscopic Analysis ◽  
Silty Clay ◽  
Soil Particles ◽  
Port Area ◽  
Average Aspect Ratio ◽  
Typical Soil

Microscopic analysis of soils has attracted wide attention, but at present, the analysis of particle shape of soft clay is still scarce. In this paper, the fractal dimension of particle aspect ratio, roundness and roughness is studied by selecting typical soil samples in Tianjin Port area. The main conclusions are as follows: (1) The average aspect ratio of clay, silty clay and silt is 1.56, 1.58 and 1.65, respectively, which shows that the smaller the soil particles are, the smaller the aspect ratio of the whole soil sample is; (2) The average roundness of clay, silty clay and silt are 0.91, 0.89 and 0.88, respectively, which indicates that the smaller the soil particles are, the closer the roundness of the whole soil sample is to 1, the closer the soil particles are to the circle. (3) The smaller the soil particles are, the smoother the surface of the particles is, and the smaller the soil particles are, the more obvious the correlation is.

scholarly journals Atmospheric Ice Particle Shape Estimates from Polarimetric Radar Measurements and In Situ Observations

2017 ◽  
Vol 34 (12) ◽  
pp. 2569-2587 ◽  
Author(s):  
Sergey Y. Matrosov ◽  
Carl G. Schmitt ◽  
Maximilian Maahn ◽  
Gijs de Boer
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Characteristic Size ◽  
In Situ Measurements ◽  
Department Of Energy ◽  
Depolarization Ratio ◽  
Suggested Approach ◽  
Aspect Ratios ◽  
Radar Measurements

AbstractA remote sensing approach to retrieve the degree of nonsphericity of ice hydrometeors using scanning polarimetric Ka-band radar measurements from a U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program cloud radar operated in an alternate transmission–simultaneous reception mode is introduced. Nonsphericity is characterized by aspect ratios representing the ratios of particle minor-to-major dimensions. The approach is based on the use of a circular depolarization ratio (CDR) proxy reconstructed from differential reflectivity ZDR and copolar correlation coefficient ρhυ linear polarization measurements. Essentially combining information contained in ZDR and ρhυ, CDR-based retrievals of aspect ratios are fairly insensitive to hydrometeor orientation if measurements are performed at elevation angles of around 40°–50°. The suggested approach is applied to data collected using the third ARM Mobile Facility (AMF3), deployed to Oliktok Point, Alaska. Aspect ratio retrievals were also performed using ZDR measurements that are more strongly (compared to CDR) influenced by hydrometeor orientation. The results of radar-based retrievals are compared with in situ measurements from the tethered balloon system (TBS)-based video ice particle sampler and the ground-based multiangle snowflake camera. The observed ice hydrometeors were predominantly irregular-shaped ice crystals and aggregates, with aspect ratios varying between approximately 0.3 and 0.8. The retrievals assume that particle bulk density influencing (besides the particle shape) observed polarimetric variables can be deduced from the estimates of particle characteristic size. Uncertainties of CDR-based aspect ratio retrievals are estimated at about 0.1–0.15. Given these uncertainties, radar-based retrievals generally agreed with in situ measurements. The advantages of using the CDR proxy compared to the linear depolarization ratio are discussed.

Increasing aspect ratio of particles suppresses buckling in shells formed by drying suspensions

Soft Matter ◽  
2020 ◽  
Vol 16 (42) ◽  
pp. 9643-9647
Author(s):  
Ahmed Al Harraq ◽  
Bhuvnesh Bharti
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Colloidal Suspensions ◽  
Shape Anisotropy

The article identifies the role of particle shape anisotropy in suppressing the buckling of drying droplets of colloidal suspensions.

Directional recrystallization and microstructures of an Fe–6.5wt%Si alloy

2009 ◽  
Vol 24 (8) ◽  
pp. 2654-2660 ◽  
Author(s):  
Zhongwu Zhang ◽  
Guang Chen ◽  
Hongbin Bei ◽  
Feng Li ◽  
Feng Ye ◽  
...  
Keyword(s):  
Growth Rate ◽  
Aspect Ratio ◽  
Grain Orientation ◽  
Growth Parameters ◽  
Ratio Increase ◽  
Average Aspect Ratio ◽  
Columnar Grains ◽  
Energy Surfaces ◽  
Hot Zone ◽  
Zone Temperature

Directional recrystallization of an Fe–6.5wt%Si alloy was investigated by changing hot zone temperatures and growth rates. Elongated (columnar) grains with an aspect ratio more than 10 can be produced when growth parameters are carefully adjusted. It was found that at a fixed growth rate, the grain length and aspect ratio increase with increased hot zone temperatures. At a fixed hot zone temperature, there is a critical growth rate at which columnar grains have the largest average aspect ratio. Below or above this growth rate, the aspect ratio decreases. Texture and grain orientation analysis showed that the preferentially selective growth to form columnar grains was favored by the formation of low-energy surfaces and grain boundaries.

scholarly journals Aspect-ratio-dependent interaction of molecular polymer brushes and multicellular tumour spheroids

2018 ◽  
Vol 9 (25) ◽  
pp. 3461-3465 ◽  
Author(s):  
Markus Müllner ◽  
Kylie Yang ◽  
Amandeep Kaur ◽  
Elizabeth J. New
Keyword(s):  
Aspect Ratio ◽  
Surface Chemistry ◽  
Particle Shape ◽  
Polymer Brushes ◽  
Design Parameters ◽  
Tumour Spheroid ◽  
Tumour Spheroids ◽  
Shape Effects ◽  
Nanoparticle Design ◽  
Dependent Interaction

Molecular polymer brushes allow for independent tailoring of nanoparticle design parameters. Brush particles with altered shape and aspect ratio revealed that particle shape effects may be decoupled from surface chemistry to achieve higher tumour spheroid interaction and penetration.

scholarly journals Study of the island morphology at the early stages of Fe/Mo(110) MBE growth

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Dmytro Goykolov ◽  
Miroslav Kotrla
Keyword(s):  
Low Temperature ◽  
Aspect Ratio ◽  
Theoretical Study ◽  
Morphological Changes ◽  
Nearest Neighbors ◽  
Sos Model ◽  
Mbe Growth ◽  
Calculated Dependence ◽  
Average Aspect Ratio ◽  
Higher Temperature

AbstractWe present theoretical study of morphology of Fe islands grown at Mo(110) surface in submonolayer MBE mode. We utilize atomistic SOS model with bond counting, and interactions of Fe adatom up to third nearest neighbors. We performed KMC simulations for different values of adatom interactions and varying temperatures. We have found that, while for the low temperature islands are fat fractals, for the temperature 500 K islands have faceted rhombic-like shape. For the higher temperature, islands acquire a rounded shape. In order to evaluate qualitatively morphological changes, we measured average aspect ratio of islands. We calculated dependence of the average aspect ratio on the temperature, and on the strength of interactions of an adatom with neighbors.

Influence of Particle Shape and Contact Parameters on DEM-Simulated Bulk Density of Wheat

2020 ◽  
Vol 63 (6) ◽  
pp. 1657-1672
Author(s):  
Marvin C. Petingco ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
Oladiran O. Fasina ◽  
Zhengpu Chen ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Bulk Density ◽  
Particle Shape ◽  
Static Friction ◽  
Rolling Friction ◽  
Particle Model ◽  
Dem Simulation ◽  
Aspect Ratios ◽  
Ellipsoidal Particles ◽  
Contact Parameters

HighlightsDecreasing aspect ratio and improved geometrical smoothness of particles increased DEM-predicted bulk density of wheat.Among the three particle models, the 5-sphere ellipsoidal particle was the best option to represent wheat particles, as indicated by the simulated bulk densities that best agreed with the experiments.Among the contact parameters, the wheat-to-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the greatest influence on simulated bulk density.Abstract. The discrete element method (DEM) has been shown to be an effective tool for simulating the behavior of granular material. The accuracy of simulations depends highly on the contact models, particle physical parameters, and contact parameters used. The objectives of this study were to determine the influence of particle shape and contact parameters on simulated wheat bulk density and to develop an effective wheat particle model for DEM simulation of filling a container using EDEM software. Grain characteristics, including single-kernel weight, kernel density, kernel dimensions, aspect ratio, and bulk density, were determined for three size fractions of wheat used in the experiments. Three categories of particle models (5-sphere pseudo-ellipsoidal, 7-sphere pseudo-ellipsoidal, and ASG-generated) with varying aspect ratios and geometrical smoothness were tested in the simulations. Results showed that DEM-simulated bulk density of wheat increased with lower aspect ratio and greater geometrical smoothness of pseudo-ellipsoidal particles (7-sphere versus 5-sphere). Increasing the number of spheres to approximately 30 for better representation of wheat kernel shape, using ASG-generated particles, did not reproduce the trend of greater simulated bulk density seen in the experiments. Among the six contact parameters, the wheat-wheat coefficient of static friction and wheat-surface coefficient of rolling friction had the most significant effect on the simulated bulk density. Among the different sets of particle models, the 5-sphere pseudo-ellipsoidal particles, having aspect ratios close to that of wheat kernels in each size fraction, were found to be the most practical and appropriate particle model for use in DEM simulation of wheat bulk density. This study contributes to better understanding of the influence of particle shape and contact parameters on DEM-simulated bulk density and provides a calibrated particle model for use in simulating container filling operations. Keywords: Bulk density, Contact parameters, DEM, Particle shape, Wheat.

scholarly journals A General Method for Estimating Bulk 2D Projections of Ice Particle Shape: Theory and Applications

2019 ◽  
Vol 76 (1) ◽  
pp. 305-332 ◽  
Author(s):  
Edwin L. Dunnavan ◽  
Zhiyuan Jiang
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Ratio Distribution ◽  
Aspect Ratios ◽  
Shape Uncertainty ◽  
Aspect Ratio Distribution ◽  
Spheroidal Geometry ◽  
Orientation Parameters ◽  
General Method

Abstract The orientation of falling ice particles directly influences estimates of microphysical and radiative bulk quantities as well as in situ retrievals of size, shape, and mass. However, retrieval efforts and bulk calculations often incorporate very basic orientations or ignore these effects altogether. To address this deficiency, this study develops a general method for projecting bulk distributions of particle shape for arbitrary orientations. The Amoroso distribution provides the most general bulk aspect ratio distribution for gamma-distributed particle axis lengths. The parameters that govern the behavior of this aspect ratio distribution depend on the assumed relationship between mass, maximum dimension, and aspect ratio. Individual spheroidal geometry allows for eccentricity quantities to linearly map onto ellipse analogs, whereas aspect ratio quantities map nonlinearly. For particles viewed from their side, this analytic distinction leads to substantially larger errors in projected aspect ratio than for projected eccentricity. Distribution transformations using these mapping equations and numerical integration of projection kernels show that both truncation of size distributions and changes in Gaussian dispersion can alter the modality and shape of projection distributions. As a result, the projection process can more than triple the relative entropy between the spheroidal and projection distributions for commonly assumed model and orientation parameters. This shape uncertainty is maximized for distributions of highly eccentric particles and for particles like aggregates that are thought to fall with large canting-angle deviations. As a result, the methods used to report projected aspect ratios and the corresponding values should be questioned.

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