Integrating multi-fractal theory and geo-statistics method to characterize the spatial variability of particle size distribution of minesoils

Geoderma ◽  
2018 ◽  
Vol 317 ◽  
pp. 39-46 ◽  
Author(s):  
Jinman Wang ◽  
Xiao Lu ◽  
Yu Feng ◽  
Ruixuan Yang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Spatial Variability ◽  
Size Distribution ◽  
Fractal Theory

scholarly journals Green Preparation, Spheroidal, and Superior Property of Nano-1,3,5,7-Tetranittro-1,3,5,7-Tetrazocane

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xinlei Jia ◽  
Jingyu Wang ◽  
Conghua Hou ◽  
Yingxin Tan
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Fractal Dimension ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fractal Theory ◽  
Crystal Form ◽  
Decomposition Temperature ◽  
Scanning Calorimetry ◽  
The Impact

Herein, a green process for preparing nano-HMX, mechanical demulsification shearing (MDS) technology, was developed. Nano-HMX was successfully fabricated via MDS technology without using any chemical reagents, and the fabrication mechanism was proposed. Based on the “fractal theory,” the optimal shearing time for mechanical emulsification was deduced by calculating the fractal dimension of the particle size distribution. The as-prepared nano-HMX was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). And the impact sensitivities of HMX particles were contrastively investigated. The raw HMX had a lower fractal dimension of 1.9273. The ideal shearing time was 7 h. The resultant nano-HMX possessed a particle size distribution ranging from 203.3 nm to 509.1 nm as compared to raw HMX. Nano-HMX particles were dense spherical, maintaining β-HMX crystal form. In addition, they had much lower impact sensitivity. However, the apparent activation energy as well as thermal decomposition temperature of nano-HMX particles was decreased, attributing to the reduced probability for hotspot generation. Especially when the shearing time was 7 h, the activation energy was markedly decreased.

Spatial Variability of Soil Particle-Size Distribution Heterogeneity in Farmland

2018 ◽  
Vol 61 (2) ◽  
pp. 591-601
Author(s):  
Jilong Liu ◽  
Lingling Zhang ◽  
Qiang Fu ◽  
Gaoqi Ren ◽  
Lu Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Spatial Variability ◽  
Soil Properties ◽  
Size Distribution ◽  
Soil Particle ◽  
Soil Particle Size ◽  
Multi Scale ◽  
Soil Particle Size Distribution ◽  
Single Scale

Abstract. The objective of this research was to reveal the spatial variability of soil particle-size distribution heterogeneity. The farmland (48 m × 48 m) used in this study is located in the black soil region of northeast China and was divided into sixty-four 6 m × 6 m squares for sampling. The soil particle-size distribution was measured with a Mastersizer 2000. Soil particle-size distribution heterogeneity, the spatial variability of soil particle-size distribution heterogeneity, and the relationships between soil particle-size distribution heterogeneity and the clay, silt, and sand contents were studied by applying multifractal, geostatistical, and joint multifractal methods, respectively. The soil particle-size distribution had multifractal characteristics. Local information causing soil particle-size distribution heterogeneities were mainly low values of soil particle-size distribution; heterogeneities from the low-value side of the particle-size distribution were larger than those from the high-value side of the particle-size distribution. In the different soil layers, the degree of variation in soil particle-size distribution heterogeneities was moderate, with spatial correlation ranges of 37.82 m and moderate spatial dependences. At the single scale and multi-scale, the impacts of the clay, silt, and sand contents on the soil particle-size distribution heterogeneity changed with soil layer depth. The clay, silt, and sand contents had different degrees of influence on the spatial variability of soil particle-size distribution heterogeneity at the single scale and multi-scale. Multi-scale analysis could better reveal the degrees of influence of the above soil properties on the spatial variability of soil particle-size distribution heterogeneity. The results of this study enrich the knowledge of the spatial variability of soil properties and provide a reference and additional information for the quantitative characterization of soil particle-size distribution heterogeneity and soil management in this research area. Keywords: Geostatistics, Multifractal analysis, Relationship, Soil property.

scholarly journals Using Multi-Fractal and Joint Multi-Fractal Theories to Characterise the Spatial Variability of Soil Particle Size Distribution in an Underground Coalmine Area

2021 ◽  
Author(s):  
Sijia Li ◽  
Jinman Wang ◽  
Jiarui Zhang ◽  
Min Zhang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Spatial Variability ◽  
Size Distribution ◽  
Coal Mining ◽  
Spatial Correlation ◽  
Land Reclamation ◽  
Mining Area ◽  
Fractal Method ◽  
Coal Mining Subsidence

Abstract Underground coal mining leads to serious surface deformation, which negatively affects the physical properties of soils Soil particle size distribution (PSD) is one of the most basic soil physical characteristic that influences other important properties such as soil hydraulics and thermodynamics. Understanding the spatial variability of the soil PSD in subsided land can provide targeted guidance for land reclamation. In this study, we conducted a quantitative study on the spatial variability of the soil PSD in the Pingshuo mining area on the Loess plateau, Shanxi Province in China, and explored the effects of subsidence and reclamation on the soil PSD. A plot experiment, including one unmined plot (UMP), one subsided plot (SUP), and one reclaimed plot (RCP), was performed in Anjialing No.3 underground coal mine in the, Pingshuo mining area. Four multi-fractal parameters of the soil PSD—D(0), D(1), Δα(q), and Δf(α)—were analyzed at the three sample sites. The joint multi-fractal method was carried out to analyze the spatial correlation of the soil PSD to further reveal the impacts of coal mining subsidence and land reclamation on the soil PSD. The multi-fractal method can reflect the local non-uniformity and heterogeneity of the soil PSD, while the joint multi-fractal approach can illustrate the correlation of the soil PSD between different soil depths. The range and spatial variability of the soil PSD increased due to coal mining subsidence and the impact of subsidence on the spatial disturbance of the surface soil PSD was greater than that of the deeper layers. The spatial correlation of clay in subsided land was larger than those of unmined land and reclaimed land, whereas, for silt and sand, the correlation was smaller. Land reclamation decreased the spatial variability of the soil PSD, which was near that of the unmined land after reclamation.

scholarly journals Evaluation of particle size distribution of granular blasting materials based on the fractal theory

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988156 ◽  
Author(s):  
Jiejie Ji ◽  
Qiang Yao ◽  
Faming Wu ◽  
Hongtao Li
Keyword(s):  
Particle Size ◽  
Fractal Dimension ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Evaluation Method ◽  
Fractal Theory ◽  
Distribution Model ◽  
Uniformity Coefficient ◽  
Functional Relationships ◽  
Fine Grain

The particle size distribution of granular blasting materials has a vital influence on the filling quality of earth-rockfill dams. The engineering experience-based method used to evaluate the particle size distribution has shortcomings at both the theoretical and practical aspects. This article proposes a new evaluation method based on the fractal theory. Grading sieve tests on granular materials, mass fractal analysis of particle size distribution, and a probability distribution model test of the characteristic parameters are used to revise the functional relationships between the fractal dimension D and the uniformity coefficient/curvature coefficient ( Cu/ Cc) of the grading curve. The feasibility of using D to evaluate the particle size distribution and the optimal fine grain content is then analyzed and determined. According to the results, the geometric shapes of the granular blasting materials have fractal characteristics, and their particle size distribution has a fractal distribution. The ranges of D where the rockfill and transition materials have a good particle size distribution are D = 2.254–2.529 and D = 2.358–2.559, corresponding to optimal fine grain content of 1.953%–11.805% and 10.268%–23.123%, respectively. Fractal dimension has a solid theoretical basis and strong practical applicability as an evaluation index for the particle size distribution of granular blasting materials.

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