Research on Fractal Characteristics of Cement-Based Materials by Nitrogen Adsorption Method

2011 ◽  
Vol 415-417 ◽  
pp. 1545-1552 ◽  
Author(s):  
Ming Tang ◽  
Jing Qi Li
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Surface Area ◽  
Nitrogen Adsorption ◽  
Surface Characteristics ◽  
Adsorption Method ◽  
Surface Fractal Dimension ◽  
Surface Fractal ◽  
Cement Based Materials ◽  
Fractal Characteristics

In order to confirm the surface fractal dimension of the internal pore of complex porous materials by means of the FHH model and nitrogen adsorption method. Study the change rule on fractal characteristics of the pore of cement based materials further. The results shows that, surface area of the complex internal structure of cement based materials has the fractal characteristics observably. Testing and evaluating the fractal characteristics on surface area of the pore of cement-based materials is effective by nitrogen adsorption method. It is good for analyzing surface characteristics of pore structure further. Surface fractal dimension of pore structure and surface area have not good correlation. The characteristics and conclusion that quality fractal dimension of powder and surface area evaluating fineness of powder have not very good correlation is consistent.

Application of Fractal Theory on River Bed Form

2012 ◽  
Vol 212-213 ◽  
pp. 236-240 ◽  
Author(s):  
Yin Jun Zhou ◽  
Fei Li ◽  
Li Chen ◽  
Zhong Wu Jin ◽  
Jun Wang
Keyword(s):  
Fractal Dimension ◽  
Surface Area ◽  
Fractal Theory ◽  
Irregular Boundary ◽  
Surface Fractal Dimension ◽  
Surface Fractal ◽  
River Bed ◽  
Bed Form ◽  
Fractal Characteristics ◽  
River Pattern

Fractal theory is used to describe river bed form. Based on improvements in some aspects of Surface area – Scale Method, such as, estimation of surface area, boundary treatment and so on, the calculation method of surface fractal dimension with irregular boundary is obtained, and the new method has good application on the bed surface fractal dimension calculation. The fractal characteristics of river bed surface morphology are discussed by combination with river-pattern, river regime, river process and changes of BSD. BSD can be used to study some related problems, such as analysis of river regime, distinction of river pattern, calculation of river resistance and so on.

Research on the Pore Structure of Alkali-Slag Cement Stone Activated with Water Glass

2011 ◽  
Vol 194-196 ◽  
pp. 899-903 ◽  
Author(s):  
Juan He ◽  
Chang Hui Yang
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Water Glass ◽  
Fractal Theory ◽  
Cement Stone ◽  
Pore Surface ◽  
Slag Cement ◽  
Adsorption Method ◽  
Surface Fractal Dimension ◽  
Surface Fractal

In view of the phenomena that alkali-slag cement has high mechanical strength and good impermeability and they are closely related with the pore structure of cement stone,water glass was selected as the alkali activater, nitrogen adsorption method was adopted to study the pore structure of alkali-slag cement stone, while the pore surface fractal dimension was determined by fractal theory. The results show that the pore structure of alkali-slag cement stone posesses obvious fractal characters and that fits the Frenkel-Halsey-Hill(FHH) model quite well.So the pore surface fractal dimension can be used to synthetically evaluate the superior or inferior of the pore structure of cement stone.

Nano/Micro Pore Structure and Fractal Characteristics of Baliancheng Coalfield in Hunchun Basin

2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Coal Reservoir

The pore structure characteristic is an important index to measure and evaluate the storage capacity and fracturing coal reservoir. The coal of Baliancheng coalfield in Hunchun Basin was selected for experiments including low temperature nitrogen adsorption method, Argon Ion milling Scanning Electron Microscopy (Ar-SEM), Nuclear Magnetic Resonance (NMR), X-ray diffraction method, quantitative mineral clay analysis method. The pore structure of coal was quantitatively characterized by means of fractal theory. Meanwhile, the influences of pores fractal dimension were discussed with experiment data. The results show that the organic pores in Baliancheng coalfield are mainly plant tissue pores, interparticle pores and gas pores, and the mineral pores are corrosion pores and clay mineral pores. There are mainly slit pore and wedge-shaped pore in curve I of Low temperature nitrogen adsorption. There are ink pores in curve II with characteristics of a large specific surface area and average pore diameter. The two peaks of NMR T2 spectrum indicate that the adsorption pores are relatively developed and their connectivity is poor. The three peaks show the seepage pores and cracks well developed, which are beneficial to improve the porosity and permeability of coal reservoir. When the pore diameter is 2–100 nm, the fractal dimensions D1 and D2 obtained by nitrogen adsorption experiment. there are positive correlations between water content and specific surface area and surface fractal dimension D1, The fractal dimension D2 was positively and negatively correlated with ash content and average pore diameters respectively. The fractal dimensions DN1 and DN2 were obtained by using the NMR in the range of 0.1 μm˜10 μm. DN1 are positively correlated with specific surface area of adsorption pores. DN2 are positively correlated volume of seepage pores. The fractal dimension DM and dissolution hole fractal dimension Dc were calculated by SEM image method, respectively controlled by clay mineral and feldspar content. There is a remarkable positive correlation between D1 and DN1 and Langmuir volume of coal, so fractal dimension can effectively quantify the adsorption capacity of coal.

Surface fractal dimension of microporous carbon fibres by nitrogen adsorption

1991 ◽  
Vol 87 (1) ◽  
pp. 179 ◽  
Author(s):  
Katsumi Kaneko ◽  
Mutsumi Sato ◽  
Takaomi Suzuki ◽  
Yoko Fujiwara ◽  
Keiko Nishikawa ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Nitrogen Adsorption ◽  
Microporous Carbon ◽  
Carbon Fibres ◽  
Surface Fractal Dimension ◽  
Surface Fractal

scholarly journals An Investigation of Fractal Characteristics of Marine Shales in the Southern China from Nitrogen Adsorption Data

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jian Xiong ◽  
Xiangjun Liu ◽  
Lixi Liang
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Southern China ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Mean Value ◽  
Relative Pressure ◽  
Pore Surface ◽  
Adsorption Sites ◽  
Fractal Characteristics

We mainly focus on the Permian, Lower Cambrian, Lower Silurian, and Upper Ordovician Formation; the fractal dimensions of marine shales in southern China were calculated using the FHH fractal model based on the low-pressure nitrogen adsorption analysis. The results show that the marine shales in southern China have the dual fractal characteristics. The fractal dimensionD1at low relative pressure represents the pore surface fractal characteristics, whereas the fractal dimensionD2at higher relative pressure describes the pore structure fractal characteristics. The fractal dimensionsD1range from 2.0918 to 2.718 with a mean value of 2.4762, and the fractal dimensionsD2range from 2.5842 to 2.9399 with a mean value of 2.8015. There are positive relationships between fractal dimensionD1and specific surface area and total pore volume, whereas the fractal dimensionsD2have negative correlation with average pore size. The larger the value of the fractal dimensionD1is, the rougher the pore surface is, which could provide more adsorption sites, leading to higher adsorption capacity for gas. The larger the value of the fractal dimensionD2is, the more complicated the pore structure is, resulting in the lower flow capacity for gas.

Experimental Study on Coal Pore Characteristic Based on Cryogenic Liquid Nitrogen Method

2013 ◽  
Vol 341-342 ◽  
pp. 345-350 ◽  
Author(s):  
Wei Min Cheng ◽  
Xiao Qiang Zhang ◽  
Rui Zhang ◽  
Gang Wang
Keyword(s):  
Pore Structure ◽  
Surface Area ◽  
Liquid Nitrogen ◽  
Pore Volume ◽  
Single Point ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Cryogenic Liquid ◽  
Adsorption Method ◽  
Point Total

In view of pore distribution in coal, this paper applies BJH method that is based on the cylinder theory and adopts cryogenic liquid nitrogen adsorption method to carry out experimental investigation on pore structure of No.3U coal seam in Sanhekou Coalmine, obtaining the fact that pore structure of No.3U coal is complicated, the cool pores are mostly flask pores, others are the parallel plate pores with one end closed and the cylinder pores with one end closed; According to the distribution of BJH pore volume and pore surface area, ultramicropores with apertures less than 10 nm are among the most; Then obtain the average BET specific surface area, the distribution of BJH pore volume and pore area, average single-point total pore volume and most probable pore .etc, which conducive to a better understanding of the micropores characteristic of coal.

SURFACE FRACTAL DIMENSION OF BENTONITE AND ITS APPLICATION IN CALCULATION OF SWELLING DEFORMATION

2014 ◽  
Vol 21 (05) ◽  
pp. 1450074 ◽  
Author(s):  
G. S. XIANG ◽  
Y. F. XU ◽  
H. JIANG
Keyword(s):  
Fractal Dimension ◽  
Nitrogen Adsorption ◽  
Fractal Model ◽  
Diffuse Double Layer ◽  
Osmotic Swelling ◽  
Overburden Pressure ◽  
Surface Fractal Dimension ◽  
Surface Fractal ◽  
Deformation Test ◽  
Deformation Tests

The correlation between the void ratio of swelled montmorillonite and the vertical overburden pressure can be expressed as [Formula: see text]. The surface fractal dimension D s of five bentonites were estimated from the swelling deformation tests according to this fractal correlation. The reliability of surface fractal dimension obtained from the swelling deformation test was confirmed by nitrogen adsorption test, with identical values of surface fractal dimension obtained from both tests. The surface fractal dimension can also be used to estimate the swelling deformation of bentonite, after calculating the swelling coefficient K from the parameters of diffuse double layer (DDL) model in the osmotic swelling phase. Comparison of the model predictions with a number of experimental results on swelling deformation of both Na dominant and Ca dominant bentonites suggests that the surface fractal model works excellent in the cases tested.

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