Investigate on Pore Structure Characteristics of Reactive Powder Concrete after High Temperatures

2012 ◽  
Vol 174-177 ◽  
pp. 1010-1014 ◽  
Author(s):  
Hong Bin Liu ◽  
Yang Ju ◽  
Kai Pei Tian ◽  
Jin Hui Liu ◽  
Li Wang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Pore Volume ◽  
Average Pore Size ◽  
Reactive Powder Concrete ◽  
Characteristic Parameters ◽  
Average Pore ◽  
Structure Characteristics ◽  
Temperature Levels ◽  
Reactive Powder

The pore structure characteristics of reactive powder concrete (RPC) were investigated by means of the mercury injection method at seven temperature levels, namely, 20°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, respectively. The characteristic parameters such as porosity, pore volume, average pore size and threshold aperture varied with temperatures were analyzed. The results indicate that the porosity, pore volume, threshold aperture and other characteristic parameters of RPC increased with the temperature increasing.

Effect of Heat-Treatment in Ar Atmosphere on Pore Structure of Carbonaceous Materials from Polysiloxane

2014 ◽  
Vol 602-603 ◽  
pp. 279-284
Author(s):  
Li Qun Duan ◽  
Chen Chen Zhang ◽  
Qing Song Ma ◽  
Zhao Hui Chen
Keyword(s):  
Heat Treatment ◽  
Pore Structure ◽  
Pore Size ◽  
Pore Volume ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Treatment Temperature ◽  
Carbonaceous Materials ◽  
Average Pore ◽  
Pore Size Distributions

Nanoporous carbonaceous materials derived from polysiloxane were first prepared by pyrolysis at 1300°C followed with hydrofluoric acid (HF) etching treatment. Their thermal stability of pore structure in inert condition was investigated in this paper by nitrogen adsorption technique in detail. The specific surface area (SSA) and pore volume (total pore volume, micropore volume, mesopore volume) decreased continually in the heat-treatment temperature range of 1000~1400°C. The average pore size almost kept the same with the raw sample. However, when the temperature exceeded 1400°C, the micropore interconnection began transforming to mesopore structure, which led to the decline of SSA and the increase of average pore size. Furthermore, the pore size distributions (PSDs) curves showed that heat-treatment had an advantage on the transition process of pore structure from disorder to regularity to some extent when heat-treated in the range 1000~1400°C for the most possible reason of relief of residue strain in the carbonaceous materials.

PORE STRUCTURE CHARACTERIZATION FOR A CONTINENTAL LACUSTRINE SHALE PARASEQUENCE BASED ON FRACTAL THEORY

Fractals ◽  
2019 ◽  
Vol 27 (01) ◽  
pp. 1940006 ◽  
Author(s):  
LEI ZHANG ◽  
XUEJUAN ZHANG ◽  
HAO CHAI ◽  
YAOCAI LI ◽  
YONGJIE ZHOU
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Pore Size ◽  
Clay Mineral ◽  
Mineral Content ◽  
Fractal Theory ◽  
Average Pore Size ◽  
Structure Characterization ◽  
Imaging Method ◽  
Average Pore

Fractal dimension is an important parameter in the evaluation of tight reservoirs. For an outcrop section of the Nenjiang formation in the Songliao Basin, China, the pore structure and pore fractal characteristics of shale parasequences were investigated using fractal theory. In addition, factors causing pore structure changes were analyzed using the results of low-temperature nitrogen adsorption and scanning electron microscope (SEM) experiments. Conducive to gas migration and secondary pores development such as dissolution, results showed that nanoscale pores dominated by fracture-like morphology and consequent good internal connectivity were observed in each pore size section within the target layer. Each parasequence is characterized by a sequential upward decrease of average pore size and an upward increase of total pore volume, with an increasing number of pores from 2[Formula: see text]nm to 50[Formula: see text]nm. Pores are isolated from each other, with poor connectivity and relatively complex composition of brittle minerals and clay minerals. Main components of the brittle minerals, quartz and feldspar, occur in 20–50% and higher clay mineral content ranging from 50% to 70%. In the parasequence cycle, clay mineral gradually decreases while the brittle mineral content increases. Fractal dimension is negatively correlated with clay mineral content and positively correlated with brittle mineral (quartz and feldspar) content. The fractal dimension calculated by the imaging method and the FHH method shows an upward increasing tendency in each of the parasequence cycles. This is as a result of different phenomena, varied sediment hydrodynamic forces leading to particle size differences and increased brittle minerals resulting in microcracks, therefore, the fractal dimension of the large pores (imaging method) increases upward in the parasequence. Simultaneously, with increased content and accompanied dissolution of brittle minerals causing an increase of small pores from base to top of the parasequence, the fractal dimension of the small pores (FHH method) grows.

Research on the Porosity and Pore Size of Spun-Bonded Fabrics Based on Matlab7.0 Image Processing Technology

2012 ◽  
Vol 601 ◽  
pp. 99-104 ◽  
Author(s):  
Ru Fang Yuan ◽  
Yong Yang Wang ◽  
Cheng Yan Zhu
Keyword(s):  
Image Processing ◽  
Pore Structure ◽  
Pore Size ◽  
Pore Volume ◽  
Average Pore Size ◽  
Filter Material ◽  
Test Method ◽  
Processing Technology ◽  
Filter Performance ◽  
Image Processing Technology

The image with high resolution was obtained through scanning the spun-bonded fabric, and processed with the help of Matlab7.0 software to calculate the pore structure of the spun-bonded fabric. On the basis of the relationship between number of pixels and area, the porosity and average pore size of spun-bonded fabric were analyzed; pore size and porosity were calculated by using the equation method and the air bubble test method as well. By comparing the data of the two methods, the correlation between them was gotten. Finally, it was shown that using the image processing technology to research the pore structure of spun-bonded fabric was a feasible way. There are various factors affecting the performance of textile filtering materials, and the porosity and pore size of the fabrics play an important role in filtration. As is known to all, fabric porosity and pore size are indicators to measure the size of fabric pore volume, one is the ratio of pore volume with the total fabric volume, and the other one refers to the average diameter of the holes in the textile filter material. They directly affect the permeability, the hydraulic conductivity of the fabric and the ability to prevent the particles getting through. Generally speaking, the bigger the porosity and pore size, the greater the permeability coefficient and the better the permeability of the filter material. Porosity and pore size directly affect the product's function and application. Therefore, the pore structure has a great impact on textile filter performance [1]. Nowadays, the formula method was generally used to calculate the porosity, and the bubble method was always used in testing pore size.

The Effect of the Freeze-Thaw Cycles in Nanometer Pores on the Cement Structure

2014 ◽  
Vol 488-489 ◽  
pp. 620-624
Author(s):  
Long Zhou ◽  
Xu Liang Hou ◽  
Zhong Ping Wang
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Average Pore Size ◽  
Pore Wall ◽  
Average Pore ◽  
Freeze Thaw ◽  
Changing Trends ◽  
Bet Method ◽  
Resistance Durability ◽  
20 Nm

The pore structure of cement-based materials is closely related to the freeze-thaw resistance durability. And this paper focused on nanometer pores to verify the connection of freeze-thaw cycles in the nanometer pores with the structure deterioration and to explore the stress in the pore wall during the freeze-thaw process. And BET method was adopted to analyze the pore structure of the cement and results indicated the changing trends of parameters such as the pore volume, average pore size and surface area of specimens. Moreover, pore size distribution presented prominent fluctuations of pore sizes in the range of 0 ~ 20 nm, while the changes on the scale of 20 ~ 100 nm were limited.

Development of a Collagen-Gag Copolymer Implant for the Study of Tendon Regeneration

1993 ◽  
Vol 331 ◽  
Author(s):  
L. K. Louie ◽  
I. V. Yannas ◽  
M. Spector
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Average Pore Size ◽  
Scar Tissue ◽  
Silicone Elastomer ◽  
Pore Channel ◽  
Average Pore ◽  
Pore Sizes ◽  
Tendon Regeneration ◽  
Channel Orientation

AbstractFollowing injuries resulting in a gap, tendons generally do not heal sufficiently because the defect does not fill with reparative tissue, or the resulting scar tissue is not functionally adequate. The objective of this study was to engineer a collagen-GAG (CG) copolymer to facilitate tendon regeneration. Previous work in our laboratory using similar porous resorbable analogs of extracellular matrix have led to regeneration of skin and peripheral nerve.Matrices with controlled pore structure were produced by adapting the manufacturing technique developed in our laboratory for grafts with cylindrical geometry. CG suspensions contained within silicone elastomer tubes were frozen and lyophilized in a controlled manner. Quantitative optical microscopy was used to determine the percent porosity, average pore size, and pore orientation of the matrices.The CG matrices, formed in silicone elastomer tubes, 3.8 mm in diameter, had average pore sizes ranging from 20 to 150 μm. his range of pore sizes was comparable to that obtained previously using a diameter of 1.5 mm.1 The average pore size did not appear to be strongly dependent on the tubing diameter. The homogeneity of the pore structure and the pore channel orientation could be controlled by adjusting the temperature of the bath used for freezing the CG suspension and the velocity with which the graft was immersed into the coolant bath.

Catalytic Oxidation of Toluene with Ozone Over the Ru-Mn/Desilicated Nanoporous H-Zeolite Socony Mobil-5 at Room Temperature

2021 ◽  
Vol 21 (7) ◽  
pp. 3868-3871
Author(s):  
Jihee Kim ◽  
Jung Eun Lee ◽  
Abid Farooq ◽  
Sang Chai Kim ◽  
Sang-Chul Jung ◽  
...  
Keyword(s):  
Pore Size ◽  
Catalytic Oxidation ◽  
Surface Area ◽  
Removal Efficiency ◽  
Pore Volume ◽  
Bimetallic Catalysts ◽  
Room Temperature ◽  
Average Pore Size ◽  
Average Pore ◽  
Zeolite Support

In this study, the effect of Ru-Mn bimetallic catalysts in combination with a zeolite support on the removal of toluene in the presence of ozone at room temperature was investigated. Desili-cated HZSM-5 (DZSM) was fabricated and applied as a Ru-Mn support for the removal of toluene (100 ppm) in the presence of ozone (1000 ppm) at room temperature. The surface area, pore volume, and average pore size of Ru-Mn with a DZSM support (RuMn/DZSM) were measured and compared with those of Ru-Mn/HZSM-5 (RuMn/HZSM). The pore size of RuMn/DZSM (69 Å) was much larger than that of RuMn/HZSM-5 (5.5 Å). In addition, the pore volumes of RuMn/DZSM and RuMn/HZSM were 0.64 and 0.25 cm3/g, respectively. Furthermore, the ratios of Mn3+/Mn4+ and Ovacancy/Olattice of RuMn/DZSM were larger than those of RuMn/HZSM-5. The removal efficiency of toluene of RuMn/DZSM was higher than that of RuMn/HZSM due to its larger pore volume, pore size, and the increased ratios of Mn3+/Mn4+ and Ovacancy/Olattice.

scholarly journals Synthesis and mechanism of aluminum silicate mesoporous materials by F108 template

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhijun Ma ◽  
Jing Gao ◽  
Xingyuan Weng ◽  
Shuai Yang ◽  
Kai Peng
Keyword(s):  
Pore Size ◽  
Sodium Hydroxide ◽  
Surface Area ◽  
Mesoporous Materials ◽  
Pore Volume ◽  
Average Pore Size ◽  
Molar Ratio ◽  
Aluminum Silicate ◽  
Synthetic Material ◽  
Average Pore

Abstract Aluminosilicate mesoporous materials were synthesized using F108 template (polyethylene glycol-polypropylene glycolpolyethylene glycol) at a concentration of 0.034 g/ml and the molar ratio of Al2O3 to SiO2 was 0.09. The products were then characterized using nitrogen adsorption/desorption tests, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The effects of various crystallization temperatures as well as sodium hydroxide concentrations on the average diameter, pore volume, surface area, and morphology of the synthetic material were analyzed. Results showed that a sodium hydroxide concentration of 11 mol/L and a crystallization temperature of 130 °C produced a synthetic material with regular pore size and homogeneous arrangement including a specific surface area of 137.62 m2/g, an average pore volume of 0.27 cm3/g, along with an average pore size of 15.33 nm.

scholarly journals The Leachate Release and Microstructure of the Sewage Sludge under the Anaerobic Fermentation

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Yiqie Dong ◽  
Haijun Lu ◽  
Jixiang Li ◽  
Changhong Wang
Keyword(s):  
Sewage Sludge ◽  
Mass Loss ◽  
Pore Structure ◽  
Pore Size ◽  
Ph Value ◽  
Anaerobic Fermentation ◽  
Average Pore Size ◽  
Average Pore ◽  
Adsorption Amount ◽  
Endothermic Valley

Pollutant release, pore structure, and thermal effect of sewage sludge during anaerobic fermentation were investigated. Results showed that the pH value firstly declined and then increased during anaerobic fermentation. The BOD5and organics of sewage sludge declined, and the BOD5of samples which was originally neutral declined as much as 53.6%. The micropore of samples was relatively developed. The biggest adsorption amount was 69.2 cm3/g. The average pore size was enlarged about 16.0–19.8% under anaerobic fermentation. There existed endothermic valley during heating procedure of 0–200∘C because of the dehydration, and the mass loss was 60.9–72.5%. The endothermic valley of the sample fluctuated at the 14th day in the anaerobic fermentation. During the heating procedure of 200–600∘C, there existed exothermal peaks because of the oxidation and burning of the organics. The curve of sample which was originally neutral had comparatively large endothermic valley and exothermal peak.

scholarly journals PEMANFAATAN LIMBAH SEKAM PADI MENJADI SILIKA GEL

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Prima Astuti Handayani ◽  
Eko Nurjanah ◽  
Wara Dyah Pita Rengga
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Silica Gel ◽  
Pore Volume ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Rice Hull ◽  
Rice Hull Ash ◽  
Average Pore ◽  
Ft Ir

<p>Sekam padi merupakan salah satu sumber penghasil silika terbesar, berpotensi sebagai bahan pembuatan silika gel. Abu sekam padi mengandung silika sebanyak 87%-97% berat kering. Sintesis silika gel dari abu sekam padi dilakukan dengan mereaksikan abu sekam padi menggunakan larutan NaOH 1N pada suhu 800C selama 1 jam dan dilanjutkan dengan penambahan larutan asam hingga pH=7. Gel yang dihasilkan selanjutnya didiamkan selama 18 jam kemudian dikeringkan pada suhu dikeringkan menggunakan oven pada suhu 800C hingga beratnya konstan. Hasil percobaan diperoleh bahwa silika gel dengan penambahan CH3COOH menghasilkan yield yang lebih besar dibandingkan penambahan HCl. Berdasarkan analisis FT-IR silika gel yang diperoleh memiliki gugus Si-O-Si dan gugus Si-OH. Silika gel dengan penambahan HCl memiliki surface area sebesar 65,558 m2/g, total pore volume 0,1935 cc/g, dan average pore size sebesar 59,0196 Å. Sedangkan silika gel dengan penambahan CH3COOH memiliki surface area sebesar 9,685 m2/g, total pore volume 0,02118 cc/g, dan average pore size sebesar 43,7357Å. Silika gel dengan penambahan<br />CH3COOH memiliki kemampuan menyerap kelembaban udara yang lebih baik dibanding silika gel dengan penambahan HCl.</p><p> </p><p>Rice hull ash (RHA) is one of the biggest source of silica, potential for sintesis silica gel. RHA contains silica as many as 87 % -97 %. Synthesis of silica gel from rice hull ash was done by reaction using NaOH solution at temperature 800C for 1 hour and followed by the addition of an acid solution until pH=7. The gel were rested with time aging 18 hour, and then dried using oven at temperature 800C until constant weigh. The results obtained that the silica gel with the addition of CH3COOH produce higher yields than the addition of HCl. Based on FT-IR analysis, silica gel has a group of silanol (Si-`OH) and siloxan (Si-O-Si) group. Silica gel with the addition of HCl has a surface area 65,558 m2/g, a total pore volume 0,1935 cc/g, and average pore size 59,0196 Å. While the silica gel with the addition of CH3COOH has a surface area 9.685 m2/g, a total pore volume 0,02118 cc/g, and average pore size 43,7357 Å. Silica gel with the addition of CH3COOH<br />has the ability to absorb humidity better than silica gel with the addition of HCl.</p>

Study on Environmental Materials with Pore Size and Photocatalytic Activity of Porous TiO2-Al2O3 Photocatalyst

2013 ◽  
Vol 700 ◽  
pp. 67-70 ◽  
Author(s):  
Rui Ma ◽  
Wen Jie Zhang
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Pore Size ◽  
Pore Volume ◽  
Average Pore Size ◽  
Sol Gel ◽  
Total Pore Volume ◽  
Degradation Process ◽  
Order Kinetic ◽  
Average Pore

A novel porous TiO2-Al2O3 composite as a kind of environmental material was prepared by sol-gel method. The pore size distribution is not even in the whole pore size range. When pore size is 7.049 nm, the maximum pore volume of the material is 0.06627 cm3·g-1. The average pore size for the material is 14.56 nm and the total pore volume is 0.3945 cm3·g-1, as calculated from BJH method. Photocatalytic degradation of methyl orange can be regarded as following first order kinetic reaction. After 90 min of reaction, methyl orange degradation on the material was 77.0% and the total dye decoloration rate was 95.1%, containing both adsorption and photocatalytic degradation. The intensities of both peaks in visible and UV regions decreased sharply during photocatalytic degradation process.

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