Fractal Feature of Microstructure of Porous Medium in Effective Stress

2013 ◽  
Vol 827 ◽  
pp. 394-399
Author(s):  
Hao Li
Keyword(s):  
Porous Medium ◽  
Fractal Dimension ◽  
Effective Stress ◽  
Fractal Geometry ◽  
Calculation Model ◽  
The Relationship ◽  
Pore Number

Basing on fractal geometry theory, establish fractal calculation model in effective stress, analyze and discuss the relationship between microstructure of porous medium and effective stress, reveal the influence law of the latter on the former. The results of the study show that the fractal calculation model of effective stress can describe the relationship between them. With the increase of effective stress, the fractal dimension of porous medium increases exponentially, porosity and pore number in porous medium decrease exponentially and mean radius of pore decreases.

scholarly journals A Fractal and Numerical Simulation Coupled Study of Fracture Network during Coal Mining Excavation

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Yanan Gao ◽  
Feng Gao ◽  
Man-chu Ronald Yeung
Keyword(s):  
Fractal Dimension ◽  
Fractal Geometry ◽  
Numerical Study ◽  
Fracture Network ◽  
Mining Engineering ◽  
Deformation Method ◽  
Discontinuous Deformation ◽  
Relationship Of ◽  
The Relationship ◽  
Rock Strata

This paper features a numerical study that is carried out by using discontinuous deformation method (DDA) and fractal geometry. The configurations of rock strata calculated by DDA were imported into a code that is written by using VC++ called “Fractal” to calculate the fractal dimension of the rock strata. As illustrated, a long wall mining case in China was presented. The relationship of the fractal dimension, excavation length, stress, and movement of strata were discussed. The evolution of fractal dimension can be considered as an index of instability or failure. The method proposed in this paper can be employed to predict the period weighting in long wall mining engineering.

Adsorption of etioporphyrin and Ni-etioporphyrin on a fractal silica

2001 ◽  
Vol 79 (5-6) ◽  
pp. 817-822 ◽  
Author(s):  
Josephine Mary Hill ◽  
Flora TT Ng
Keyword(s):  
Fractal Dimension ◽  
Heavy Oil ◽  
Fractal Geometry ◽  
Effective Size ◽  
Cross Sectional ◽  
Metal Compounds ◽  
X Ray ◽  
The Relationship ◽  
Ray Methods ◽  
Monolayer Coverage

Metal compounds are contaminants in heavy oil and must be removed using hydrodemetallization catalysts. To optimize the structure of hydrodemetallization catalysts it is useful to know the effective size of the metal compounds. To this end, fractal geometry has been used to determine the relationship between monolayer coverage and adsorbate size for silica by adsorbing a series of alcohols at 298 K. It was found that the silica had a fractal dimension of 2.923. Etioporphyrin and Ni-etioporphyrin were then adsorbed on the silica and their effective areas determined based on this fractal dimension. Cross-sectional areas of 4.58 and 14.8 nm2 were determined for etioporphyrin and Ni-etioporphyrin, respectively. The areas are larger than those determined by X-ray methods and likely reflect the fact that the porphyrins are solvated with solvent (cyclohexane) molecules.

scholarly journals Application of Fractal Geometry to Study the Geological Structure of the Zarin Plain (Plain Razak)

2014 ◽  
Vol 3 (11) ◽  
pp. 135-144
Author(s):  
Khadijeh Faridi Nia ◽  
Asghar Teymoorian ◽  
Mojtaba Babaei
Keyword(s):  
Fractal Dimension ◽  
Density Dependence ◽  
Fractal Geometry ◽  
Bouguer Anomaly ◽  
Geological Structure ◽  
Optimal Density ◽  
The Relationship ◽  
Rigid Shell

One of the most important steps to obtain the specified density Bouguer anomaly corrections for the topography of the page Bouguer is the most commonly used way in which the relationship between topography and Bouguer anomaly in the method assumes that topography of the rigid shell instead Isoztasi balance is maintained. The method to determine the density of Bouguer provided by fractal analyze these are the lowest density dependence the topography of the area is considered as the optimal density and the fractal relationship to the topography of the fractal dimension using the Bouguer anomaly.

scholarly journals Study on the fractal model of water immersed collapse of Soft Rock

2020 ◽  
Vol 19 (3) ◽  
pp. 486-491
Author(s):  
Lujun Ding ◽  
◽  
Yuhong Liu
Keyword(s):  
Fractal Dimension ◽  
Fractal Geometry ◽  
Water Immersion ◽  
Soft Rock ◽  
Fractal Model ◽  
Engineering Practice ◽  
Rock Disintegration ◽  
Water Swelling ◽  
The Relationship ◽  
Development And Evolution

Soft rock is a common rock mass in engineering, one of its characteristics is water swelling and disintegration. In this paper, the nonlinear fractal geometry is introduced and the correlation fractal dimension is used to study the characteristics of slate disintegration, based on the laboratory test of water immersion disintegration, the method of quality fractal dimension is used to solve the fractal dimension of the disintegration of slate, and the change of fractal dimension is used to reflect the characteristics of the softening and disintegration of slate when encountering water. The experimental results show that the fractal model can be used to fully understand the development and evolution of rock disintegration process, and to quantitatively link the relationship between rock expansion and disintegration. The conclusion has guiding significance for engineering practice.

DERIVATION OF PERMEABILITY–PORE RELATIONSHIP FOR FRACTAL POROUS RESERVOIRS USING SERIES–PARALLEL FLOW RESISTANCE MODEL AND LATTICE BOLTZMANN METHOD

Fractals ◽  
2014 ◽  
Vol 22 (03) ◽  
pp. 1440005 ◽  
Author(s):  
BAOYU WANG ◽  
YI JIN ◽  
QING CHEN ◽  
JUNLING ZHENG ◽  
YIBO ZHU ◽  
...  
Keyword(s):  
Porous Medium ◽  
Fractal Dimension ◽  
Pore Size ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Flow Resistance ◽  
Resistance Model ◽  
Porous Reservoirs ◽  
Boltzmann Method ◽  
The Relationship

Permeability of porous reservoirs plays a significant role in engineering and scientific applications. In this study, we investigated the relationship between pore size fractal dimension (Df) and its porosity, as well as that between Dfand the pore structure parameters, and consequentially developed an algorithm to generate pore spaces with arbitrary fractal dimension characterizing the pore size distribution. Using the series–parallel flow resistance model and lattice Boltzmann method (LBM) in combination, we then systematically analyzed the effects of physical properties on the fluid flows in two-dimensional (2D) context, and quantitatively derived a permeability–pore relationship for fractal porous media. The new relationship shows that: (i) the permeability of a fractal porous medium is proportional to the square of its maximum pore size λmax; (ii) the larger the fractal dimension Dfof a pore space, the smaller the flow resistance of the porous medium; (iii) porosity φ to the power of (4 - Df)/(2 - Df) is proportional to the permeability of a porous medium; (iv) similar to the Kozeny–Carman (KC) equation, the tortuosity τ has its square inversely proportional to the permeability; more importantly, it is found to be a function of porosity approximately satisfying the relationship τ = φDf-2in a fractal porous medium. Moreover, we demonstrated that the newly derived fractal permeability–pore relationship is equivalent to KC equation and Poiseuille's law respectively, at Df= 1 and Df= 2.

Optimal Density Determination of Bouguer Anomaly Using Fractal Analysis (Case of study: Charak area,IRAN)

2005 ◽  
Vol 1 (1) ◽  
pp. 21-24
Author(s):  
Hamid Reza Samadi
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Geometry ◽  
Host Rock ◽  
Bouguer Anomaly ◽  
Research Area ◽  
Density Difference ◽  
Optimal Density

In exploration geophysics the main and initial aim is to determine density of under-research goals which have certain density difference with the host rock. Therefore, we state a method in this paper to determine the density of bouguer plate, the so-called variogram method based on fractal geometry. This method is based on minimizing surface roughness of bouguer anomaly. The fractal dimension of surface has been used as surface roughness of bouguer anomaly. Using this method, the optimal density of Charak area insouth of Hormozgan province can be determined which is 2/7 g/cfor the under-research area. This determined density has been used to correct and investigate its results about the isostasy of the studied area and results well-coincided with the geology of the area and dug exploratory holes in the text area

scholarly journals Influence of Selected Model Parameters on the Electromagnetic Levitation Melting Efficiency

2021 ◽  
Vol 11 (9) ◽  
pp. 3827
Author(s):  
Blazej Nycz ◽  
Lukasz Malinski ◽  
Roman Przylucki
Keyword(s):  
Electromagnetic Levitation ◽  
Optimization Methods ◽  
Calculation Model ◽  
Model Parameters ◽  
Starting Point ◽  
Low Efficiency ◽  
The Relationship ◽  
Reactive Metals ◽  
Electromagnetic Levitation Melting ◽  
Metal Melting

The article presents the results of multivariate calculations for the levitation metal melting system. The research had two main goals. The first goal of the multivariate calculations was to find the relationship between the basic electrical and geometric parameters of the selected calculation model and the maximum electromagnetic buoyancy force and the maximum power dissipated in the charge. The second goal was to find quasi-optimal conditions for levitation. The choice of the model with the highest melting efficiency is very important because electromagnetic levitation is essentially a low-efficiency process. Despite the low efficiency of this method, it is worth dealing with it because is one of the few methods that allow melting and obtaining alloys of refractory reactive metals. The research was limited to the analysis of the electromagnetic field modeled three-dimensionally. From among of 245 variants considered in the article, the most promising one was selected characterized by the highest efficiency. This variant will be a starting point for further work with the use of optimization methods.

Research on the hydrographic survey cycle for updating navigational charts

2021 ◽  
pp. 1-13
Author(s):  
Jing Duan ◽  
Xiaoxia Wan ◽  
Jianan Luo
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Calculation Model ◽  
Impact Factors ◽  
Factors Affecting ◽  
Material Resources ◽  
Hydrographic Survey ◽  
Survey Planning ◽  
The Impact ◽  
The Relationship

Abstract Due to the vast ocean area and limited human and material resources, hydrographic survey must be carried out in a selective and well-planned way. Therefore, scientific planning of hydrographic surveys to ensure the effectiveness of navigational charts has become an urgent issue to be addressed by the hydrographic office of each coastal state. In this study, a reasonable calculation model of hydrographic survey cycle is established, which can be used to make the plan of navigational chart updating. The paper takes 493 navigational charts of Chinese coastal ports and fairways as the research object, analyses the fundamental factors affecting the hydrographic survey cycle and gives them weights, proposes to use the BP neural network to construct the relationship between the cycle and the impact factors, and finally establishes a calculation model of the hydrographic survey cycle. It has been verified that the calculation cycle of the model is effective, and it can provide reference for hydrographic survey planning and chart updating, as well as suggestions for navigation safety.

scholarly journals Development of Back-calculation Model for Aggregate Gradation Determination Using Fractal Theory

2018 ◽  
Vol 159 ◽  
pp. 01006
Author(s):  
Bagus Hario Setiadji ◽  
Supriyono ◽  
Djoko Purwanto
Keyword(s):  
Fractal Dimension ◽  
Fractal Theory ◽  
Asphalt Mixture ◽  
Fractal Dimensions ◽  
Calculation Model ◽  
Careful Consideration ◽  
Upper And Lower Bounds ◽  
Aggregate Gradation ◽  
Fractal Characteristic ◽  
Fractal Characteristics

Several studies have shown that fractal theory can be used to analyze the morphology of aggregate materials in designing the gradation. However, the question arises whether a fractal dimension can actually represent a single aggregate gradation. This study, which is a part of a grand research to determine aggregate gradation based on known asphalt mixture specifications, is performed to clarify the aforementioned question. To do so, two steps of methodology were proposed in this study, that is, step 1 is to determine the fractal characteristics using 3 aggregate gradations (i.e. gradations near upper and lower bounds, and middle gradation); and step 2 is to back-calculate aggregate gradation based on fractal characteristics obtained using 2 scenarios, one-and multi-fractal dimension scenarios. The results of this study indicate that the multi-fractal dimension scenario provides a better prediction of aggregate gradation due to the ability of this scenario to better represent the shape of the original aggregate gradation. However, careful consideration must be observed when using more than two fractal dimensions in predicting aggregate gradation as it will increase the difficulty in developing the fractal characteristic equations.

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