Aggregate-Mean Diameter and Wind-Erodible Soil Predictions Using Dry Aggregate-Size Distributions

2003 ◽  
Vol 67 (2) ◽  
pp. 425 ◽  
Author(s):  
T. M. Zobeck ◽  
T. W. Popham ◽  
E. L. Skidmore ◽  
J. A. Lamb ◽  
S. D. Merrill ◽  
...  
Keyword(s):  
Aggregate Size ◽  
Size Distributions ◽  
Mean Diameter

Aggregate-Mean Diameter and Wind-Erodible Soil Predictions Using Dry Aggregate-Size Distributions

2003 ◽  
Vol 67 (2) ◽  
pp. 425-436 ◽  
Author(s):  
T. M. Zobeck ◽  
T. W. Popham ◽  
E. L. Skidmore ◽  
J. A. Lamb ◽  
S. D. Merrill ◽  
...  
Keyword(s):  
Aggregate Size ◽  
Size Distributions ◽  
Mean Diameter

Consistent Theoretical Model of Mean Diameter and Size Distribution by Liquid Sheet Atomization

2012 ◽  
Author(s):  
Chihiro Inoue ◽  
Toshinori Watanabe ◽  
Takehiro Himeno ◽  
Seiji Uzawa ◽  
Mitsuo Koshi
Keyword(s):  
Theoretical Model ◽  
Kinetic Energy ◽  
Droplet Diameter ◽  
Velocity Profiles ◽  
Liquid Sheet ◽  
Estimation Methods ◽  
Liquid Jets ◽  
Injection Velocity ◽  
Size Distributions ◽  
Mean Diameter

A consistent theoretical model is proposed and validated for calculating droplet diameters and size distributions. The model is derived based on the energy conservation law including the surface free energy and the Laplace pressure. Under several hypotheses, the law derives an equation indicating that atomization results from kinetic energy loss. Thus, once the amount of loss is determined, the droplet diameter is able to be calculated without the use of experimental parameters. When the effects of ambient gas are negligible, injection velocity profiles of liquid jets are the essential cause of the reduction of kinetic energy. The minimum Sauter mean diameter produced by liquid sheet atomization is inversely proportional to the injection Weber number when the injection velocity profiles are laminar or turbulent. A non-dimensional distribution function is also derived from the mean diameter model and Nukiyama-Tanasawa’s function. The new estimation methods are favorably validated by comparing with corresponding mean diameters and the size distributions, which are experimentally measured under atmospheric pressure.

Aggregate size distributions in migration driven growth models

2003 ◽  
Vol 36 (3) ◽  
pp. 423-428 ◽  
Author(s):  
Jianhong Ke ◽  
Zhenquan Lin ◽  
Youyi Zhuang
Keyword(s):  
Growth Models ◽  
Aggregate Size ◽  
Size Distributions

SOIL AGGREGATE SIZE DISTRIBUTIONS USING X-RAY IMAGES

1998 ◽  
Vol 41 (4) ◽  
pp. 1207-1215 ◽  
Author(s):  
E. W. Tollner ◽  
N. D. Melear ◽  
L. A. Rodriguez ◽  
M. E. Wright
Keyword(s):  
Aggregate Size ◽  
Soil Aggregate ◽  
Size Distributions ◽  
X Ray

scholarly journals GRAINet: mapping grain size distributions in river beds from UAV images with convolutional neural networks

2021 ◽  
Vol 25 (5) ◽  
pp. 2567-2597
Author(s):  
Nico Lang ◽  
Andrea Irniger ◽  
Agnieszka Rozniak ◽  
Roni Hunziker ◽  
Jan Dirk Wegner ◽  
...  
Keyword(s):  
Grain Size ◽  
Training Data ◽  
Grain Size Analysis ◽  
Training Dataset ◽  
Size Analysis ◽  
Size Distributions ◽  
Mean Diameter ◽  
Grain Size Distributions ◽  
Gravel Bars ◽  
Uav Images

Abstract. Grain size analysis is the key to understand the sediment dynamics of river systems. We propose GRAINet, a data-driven approach to analyze grain size distributions of entire gravel bars based on georeferenced UAV images. A convolutional neural network is trained to regress grain size distributions as well as the characteristic mean diameter from raw images. GRAINet allows for the holistic analysis of entire gravel bars, resulting in (i) high-resolution estimates and maps of the spatial grain size distribution at large scale and (ii) robust grading curves for entire gravel bars. To collect an extensive training dataset of 1491 samples, we introduce digital line sampling as a new annotation strategy. Our evaluation on 25 gravel bars along six different rivers in Switzerland yields high accuracy: the resulting maps of mean diameters have a mean absolute error (MAE) of 1.1 cm, with no bias. Robust grading curves for entire gravel bars can be extracted if representative training data are available. At the gravel bar level the MAE of the predicted mean diameter is even reduced to 0.3 cm, for bars with mean diameters ranging from 1.3 to 29.3 cm. Extensive experiments were carried out to study the quality of the digital line samples, the generalization capability of GRAINet to new locations, the model performance with respect to human labeling noise, the limitations of the current model, and the potential of GRAINet to analyze images with low resolutions.

scholarly journals EXPERIMENTAL STUDY OF MEAN DROPLET SIZE FROM PRESSURE SWIRL ATOMIZER

2020 ◽  
Vol 4 (6) ◽  
pp. 49-59
Author(s):  
Sherry Amedorme
Keyword(s):  
Experimental Study ◽  
Liquid Film ◽  
Drop Size ◽  
Injection Pressure ◽  
Size Distributions ◽  
Sauter Mean Diameter ◽  
Hollow Cone ◽  
Mean Diameter ◽  
Drop Size Distributions ◽  
Exit Orifice

This experimental study undertakes the measurements of droplet Sauter Mean Diameter (SMD) at different axial distances for the hollow-cone nozzle and different radial distances from the spray centreline using a laser-diffraction-based drop size analyser in order to validate atomization model. The study also investigates the influence of injection pressure and the evaluation of two exit orifice diameters on the Sauter Mean Diameter (SMD). The drop size distributions along the nozzle centreline as well as the radial drop distributions from spray centreline are also evaluated. To enhance the physics of liquid sheet instability and liquid film breakup mechanisms, visualization of liquid film breakup as a function of injection pressure was carried out. The results show that mean droplet size (SMD) increases in the axial distance on the spray centreline but decreases with an increasing injection pressure on the spray centreline. It was observed that larger sized drops occupy the spray periphery compared to those occupying the spray core. For the nozzle exit orifice diameters of 3.5 mm and 1.5 mm, the results show that the small nozzle exhibits smaller SMDs than the bigger nozzle and the break-up lengths are different for the two nozzles. The drop size distributions at radial positions showed an increase in droplet formation through the spray downstream distances and become more uniform. The visualisation of the spray was carried out using high-speed camera and it was noted that a well-defined hollow-cone spray was captured and that the spray angle increases with the injection pressure but reduces with the liquid film length.

scholarly journals COMPATIBILITY OF BORROW MATERIAL FOR BEACH FILLS

1974 ◽  
Vol 1 (14) ◽  
pp. 77
Author(s):  
R.G. Dean
Keyword(s):  
Standard Deviation ◽  
Size Distributions ◽  
Simple Method ◽  
Mean Diameter ◽  
Single Graph

A simple method is presented for estimating the relative compatibility of borrow material being considered for beach fill purposes. The method defines the "compatible" fraction of the material as that coarser portion with the same mean diameter (in "phi" measure) as the native material on the beach. A single graph is presented which allows determination of the number of units of borrow material required to obtain one unit of compatible material. Use of this method requires that the size distributions be reasonably represented by the "lognormal" relationship and also requires knowledge of the means of the native and borrow materials and the standard deviation of the borrow material (all in phi measure). This method overcomes shortcomings of the Krumbein-James method published in 1965. Several examples are presented illustrating the application of the method presented in this paper.

scholarly journals Dependence of solar radiative forcing of forest fire aerosol on ageing and state of mixture

2003 ◽  
Vol 3 (3) ◽  
pp. 881-891 ◽  
Author(s):  
M. Fiebig ◽  
A. Stohl ◽  
M. Wendisch ◽  
S. Eckhardt ◽  
A. Petzold
Keyword(s):  
Particle Size ◽  
Forest Fire ◽  
Radiative Forcing ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Fire Plume ◽  
Coagulation Rate ◽  
Mean Diameter ◽  
Convective Mixed Layer

Abstract. During airborne in situ measurements of particle size distributions in a forest fire plume originating in Northern Canada, an accumulation mode number mean diameter of 0.34 mm was observed over Lindenberg, Germany on 9 August 1998. Realizing that this is possibly the largest value observed for this property in a forest fire plume, scenarios of plume ageing by coagulation are considered to explain the observed size distribution, concluding that the plume dilution was inhibited in parts of the plume. The uncertainties in coagulation rate and transition from external to internal mixture of absorbing forest fire and non-absorbing background particles cause uncertainties in the plume's solar instantaneous radiative forcing of 20-40% and of a factor of 5-6, respectively. Including information compiled from other studies on this plume, it is concluded that the plume's characteristics are qualitatively consistent with a radiative-convective mixed layer.

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