scholarly journals Characteristics of Pore and Fracture of Coal with Bursting Proneness Based on DIC and Fractal Theory

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5404
Author(s):  
Yutao Li ◽  
Yixin Zhao ◽  
Yaodong Jiang ◽  
Bo Zhang ◽  
Honghua Song ◽  
...  
Keyword(s):  
Fractal Theory ◽  
Geological Structure ◽  
Fracture Characteristics ◽  
X Ray ◽  
Structure Characteristics ◽  
Fracture Structure ◽  
Fractal Properties ◽  
Fractal Characteristics ◽  
Fracture Distribution ◽  
The Relationship

Coal is a complex heterogeneous and anisotropic material conformed with fractal characteristics. The pore and fracture characteristics have important influence on the dynamic disasters including rock burst and gas outburst, however, the relationship between them is not accurately investigated due to inadequate research method. The pore and fracture distribution of coal with different bursting proneness were obtained by comprehensive application of MIP, LTNAD, SEM, and X-ray CT, and then fractal theory and DIC were used to research the pore and fracture characteristics. The result indicated that the modification of MIP result by LTNAD result could effectively eliminate the adverse effect of coal matrix compressibility, exactly reflect the distribution of pore and fracture in coal, and the pore distribution of coal with different bursting proneness were quite different. Gray scale image from SEM and 3D reconstruction technology based on X-ray CT could show the geological structure, fracture structure, and pore structure characteristics of coal. The study of LTNAD, SEM, and X-ray CT showed that these methods complemented each other, the coal had fractal properties, and the fractal dimension value had a positive correlation with the bursting proneness of coal sample.

Application of Fractal Theory in Aggregate Gradation Research

2012 ◽  
Vol 204-208 ◽  
pp. 1923-1928
Author(s):  
Bo Tan ◽  
Rui Hua Yang ◽  
Yan Ting Lai
Keyword(s):  
Fractal Dimension ◽  
Fractal Theory ◽  
Asphalt Mixture ◽  
Fractal Dimensions ◽  
Aggregate Gradation ◽  
Structure Characteristics ◽  
Aggregate Distribution ◽  
Dimension Formula ◽  
Mass Fractal ◽  
Fractal Characteristics

The paper presents the fractal dimension formula of distribution of asphalt mixture aggregate diameter by the deducing mass fractal characteristics function. Taking AC-20 and SMA-20 as examples, selected 6 groups of representative grading curves within the grading envelope proposed by the present specification, and calculated their fractal dimensions. The asphalt mixture gradation has fractal dimension D (D∈(1,3)), and the fractal of continuous gradation is single while the fractal of gap-gradation shows multi-fractal with 4.75 as the dividing point. Fractal dimension of aggregate gradation of asphalt mixture reflect the structure characteristics of aggregate distribution, that is, finer is aggregate, bigger is the fractal dimension.

scholarly journals Review about the Application of Fractal Theory in the Research of Packaging Materials

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 860
Author(s):  
Qingshan Duan ◽  
Jiejie An ◽  
Hanling Mao ◽  
Dongwu Liang ◽  
Hao Li ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Theory ◽  
Inorganic Materials ◽  
Packaging Materials ◽  
Analysis Method ◽  
Characteristic Parameters ◽  
Fractal Characteristic ◽  
Fractal Characteristics ◽  
The Relationship

The work is intended to summarize the recent progress in the work of fractal theory in packaging material to provide important insights into applied research on fractal in packaging materials. The fractal analysis methods employed for inorganic materials such as metal alloys and ceramics, polymers, and their composites are reviewed from the aspects of fractal feature extraction and fractal dimension calculation methods. Through the fractal dimension of packaging materials and the fractal in their preparation process, the relationship between the fractal characteristic parameters and the properties of packaging materials is discussed. The fractal analysis method can qualitatively and quantitatively characterize the fractal characteristics, microstructure, and properties of a large number of various types of packaging materials. The method of using fractal theory to probe the preparation and properties of packaging materials is universal; the relationship between the properties of packaging materials and fractal dimension will be a critical trend of fractal theory in the research on properties of packaging materials.

scholarly journals Capillary Water Absorption and Micro Pore Connectivity of Concrete with Fractal Analysis

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 892
Author(s):  
Xiangqun Ding ◽  
Xinyu Liang ◽  
Yichao Zhang ◽  
Yanfeng Fang ◽  
Jinghai Zhou ◽  
...  
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Fractal Theory ◽  
Mineral Admixtures ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Connectivity Probability ◽  
Fractal Characteristics ◽  
Different Diameters ◽  
The Relationship

This study focuses on the relationship between the complexity of pore structure and capillary water absorption of concrete, as well as the connection behavior of concrete in specific directions. In this paper, the water absorption of concrete with different binders was tested during the curing process, and the pore structure of concrete was investigated by mercury intrusion porosimetry (MIP). The results show that the water absorption of concrete with mineral admixtures is lower, mainly due to the existence of reasonable pore structure. The effect of slag on concrete modification is more remarkable comparing with fly ash. In addition, the analysis shows that the pore with different diameters has different fractal characteristics. The connectivity probability and water absorption of unidirectional chaotic pore are linearly correlated with the pore diameter of 50–550 nm, and the correlation coefficient reaches a very significant level, and detailed analysis was undertaken to interpret these results based on fractal theory.

scholarly journals A study on the effects of the fractal characteristics of aggregates on the mechanical behavior of cemented sand and gravel

2021 ◽  
Vol 71 (342) ◽  
pp. e250
Author(s):  
L. Guo ◽  
S. Li ◽  
L. Zhong ◽  
L. Guo ◽  
L. Wang ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Elastic Modulus ◽  
Fractal Theory ◽  
Peak Stress ◽  
Aggregate Gradation ◽  
Cemented Sand ◽  
Ordinary Concrete ◽  
Fractal Characteristics ◽  
Sand And Gravel ◽  
The Relationship

Owing to complex aspects of cemented sand and gravel (CSG), such as included unscreened aggregates, CSG properties differ from those of ordinary concrete. Fractal theory is introduced to study the effects of aggregate characteristics on CSG properties, quantifying aggregate gradation and shape. Numerical simulation and analyses show that: (1) improved aggregate gradation decreases the gradation fractal dimension and increases the CSG peak stress and elastic modulus; (2) more irregularly shaped aggregates increase the shape fractal dimension and decrease the CSG peak stress and elastic modulus; (3) the relationship quantified between aggregate characteristics and CSG mechanical properties provides a theoretical basis for aggregate allocation in engineering design and construction. Mixing artificial aggregates can improve aggregate gradation but reduces CSG performance. Appropriately blending artificial and on-site aggregates achieves optimal CSG performance; in this study, this is attained using 20% artificial aggregates added under standard gradation.

Study on Geological Structural Characteristics in Zhaoguan Mine Field

2012 ◽  
Vol 229-231 ◽  
pp. 2729-2732
Author(s):  
Mei Qiu ◽  
Long Qing Shi ◽  
Guo Rui Wang ◽  
Dong Jing Xu ◽  
Qi Sun
Keyword(s):  
Structural Characteristics ◽  
Fractal Theory ◽  
Research Area ◽  
Geological Structure ◽  
General Development ◽  
Geological Structures ◽  
Mine Field ◽  
Fractal Characteristics ◽  
Structure Complexity ◽  
Tectonic Features

Based on a great deal of geological data, we analyzed the geological tectonic features of Zhaoguan mine field. On the basis of the analytical method of traditional geology, the paper revealed the general development mechanism of geological structures of this research area. Combined with the fractal theory, and taking the calculation chart of reserve in coal seam as the foundation drawing, the faults and folds can be deeply studied to obtain their fractal characteristics with geological structure complexity in this area quantificationally evaluated.

Fractal Research in Metal Material Fracture Invalidation

2013 ◽  
Vol 703 ◽  
pp. 8-11
Author(s):  
Li Hui Guo ◽  
Wan Qiang Hu
Keyword(s):  
Fractal Theory ◽  
Engineering Application ◽  
Metal Material ◽  
Fractal Models ◽  
Metal Fracture ◽  
Fractal Characteristics ◽  
Material Fracture ◽  
Reasonable Description ◽  
Relationship Of ◽  
The Relationship

Though there are a lot of rules and models for metal material fracture, it makes lots of troubles for engineering application, because of the lacking of reasonable description of fracture principle and change law. This article discusses some basic problems of applying fractal geometry to fracture research, mainly including sectional fractal characteristics and measurement, the relationship of fractal dimension and fracture toughness, and some kinds of metal fractal models. At last, application of fractal theory in metal fracture is stated.

scholarly journals Fractal Properties of Pore Distribution of Electrospun Nanofiber Membrane

2020 ◽  
pp. 96-105
Author(s):  
Bai Chun- Yu ◽  
Chen Ying ◽  
Liu Yong ◽  
Shi Luo- Yi ◽  
Chen Ru- Dong
Keyword(s):  
Fractal Dimension ◽  
Flow Resistance ◽  
Fractal Theory ◽  
Pore Width ◽  
Electrospun Nanofiber ◽  
Nanofiber Membrane ◽  
Average Pore ◽  
Fractal Properties ◽  
Width Distribution ◽  
The Relationship

Due to the complex and chaotic characteristics of elecrtospun nanofiber membrane, fractal theory is a suitable mathematical framework. Using the fractal theory, Matlab and other computer software in Mathematics, the fractal properties of pore distribution of elecrtospun nanofiber membrane and the relationship between the fractal dimension and the physical properties of nonwovens are studied. Thirty samples were produced by using polyvinyl alcohol (PVA)on the DXES-01 automatic electrostatic spinning machine; BMP images of 30 samples were obtained by TM-1000 table scanning electron microscope; The scanning electron micro-scope images were grayed by digital image processing technology, and the average pore width of the samples was further calculated by Matlab software from the gray value matrix; G-P algorithm is used to calculate the fractal dimension of pore width distribution; The relationship between air flow resistance and the fractal dimension of pore width distribution of electrospun nanofiber membrane was analyzed. Finally, the correlation fractal dimension of the average pore width of electrospun nanofiber membrane has a quadratic function relation with the air flow resistance; The correlation fractal dimension of the average pore width obtained is consistent with the fractal dimension of porosity obtained by Ting Wang under the meaning of the relative error less than 10%is the same.

Hubungan antara Luas Lesi pada Foto Toraks Penderita TB Paru Dewasa yang Memiliki Riwayat Diabetes Melitus dengan Indeks Massa Tubuh di Rumah Sakit Hasan Sadikin Bandung

2016 ◽  
Vol 1 (3) ◽  
pp. 138-144
Author(s):  
Ina Edwina ◽  
Rista D Soetikno ◽  
Irma H Hikmat
Keyword(s):  
Chest Radiograph ◽  
Chi Square ◽  
Pulmonary Tb ◽  
X Ray ◽  
Consecutive Sampling ◽  
Close Relationship ◽  
Chi Square Test ◽  
Chest X Ray ◽  
The Relationship ◽  
Diabetes Melitus

Background: Tuberculosis (TB) and diabetes mellitus (DM) prevalence rates are increasing rapidly, especially in developing countries like Indonesia. There is a relationship between TB and DM that are very prominent, which is the prevalence of pulmonary TB with DM increased by 20 times compared with pulmonary TB without diabetes. Chest X-ray picture of TB patients with DM is atypical lesion. However, there are contradictories of pulmonary TB lesion on chest radiograph of DM patients. Nutritional status has a close relationship with the morbidity of DM, as well as TB.Objectives: The purpose of this study was to determine the relationship between the lesions of TB on the chest radiograph of patients who su?er from DM with their Body Mass Index (BMI) in Hasan Sadikin Hospital Bandung.Material and Methods: The study was conducted in Department of Radiology RSHS Bandung between October 2014 - February 2015. We did a consecutive sampling of chest radiograph and IMT of DM patients with clinical diagnosis of TB, then the data was analysed by Chi Square test to determine the relationship between degree of lesions on chest radiograph of pulmonary TB on patients who have DM with their BMI.Results: The results showed that adult patients with active pulmonary TB with DM mostly in the range of age 51-70 years old, equal to 62.22%, with the highest gender in men, equal to 60%. Chest radiograph of TB in patients with DM are mostly seen in people who are obese, which is 40% and the vast majority of lesions are minimal lesions that is equal to 40%.Conclusions: There is a signifcant association between pulmonary TB lesion degree with BMI, with p = 0.03

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