Correlation between Pitch Impregnation Pressure and Pore Sizes of Graphite Block

This study aimed to investigate the effect of impregnation pressure on the decrease in porosity of impregnated bulk graphite. The correlation between pitch impregnation behavior and the pore sizes of the bulk graphite block was studied to determine the optimal impregnation pressure. The densities and porosities of the bulk graphite before and after pitch impregnation under various pressures between 10 and 50 bar were evaluated based on the Archimedes method and a mercury porosimeter. The density increased rates increased by 1.93–2.44%, whereas the impregnation rate calculated from the rate of open porosity decreased by 15.15–24.48%. The density increase rate and impregnation rate were significantly high when the impregnation pressures were 40 and 50 bar. Compared with impregnation pressures of 10, 20, and 30 bar, the minimum impregnatable pore sizes with impregnation pressures of 40 and 50 bar were 30–39 and 24–31 nm, respectively. The mercury intrusion porosimeter analysis results demonstrated that the pressure-sensitive pore sizes of the graphite blocks were in the range of 100–4500 nm. Furthermore, the ink-bottle-type pores in this range contributed predominantly to the effect of impregnation under pressure, given that the pitch-impregnated-into-ink-bottle-type pores were difficult to elute during carbonization.

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Investigation of the Porosity of Certain Iraqi Clay Deposits by Mercury Porosimeter

Baghdad Science Journal ◽

10.21123/bsj.6.1.163-172 ◽

2009 ◽

Vol 6 (1) ◽

pp. 163-172

Author(s):

Baghdad Science Journal

Keyword(s):

Pore Volume ◽

Pore Diameter ◽

Mercury Intrusion Porosimetry ◽

Narrow Range ◽

Volume Distribution ◽

Natural Clay ◽

Mercury Intrusion ◽

Clay Deposits ◽

Pore Area ◽

Mercury Porosimeter

Pore volume, pore diameter, and pore volume distribution of three of Iraqi natural clay deposites were measured using mercury intrusion porosimetry .The clays are white kaolin, colored kaolin, and bentonite .The results showed that the variation of the pore area of the clay deposites followed the following order :- Coloured Kaolin > White Kaolin > Bentonite While the pore volume may be arranged as in the following sequence:- White Kaolin > Coloured Kaolin >Bentonite Also , Bentonite exhibits the narrow range pore size distribution than the white and coloured kaolin.

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Pore Structure Damages in Cement-Based Materials by Mercury Intrusion: A Non-Destructive Assessment by X-Ray Computed Tomography

Materials ◽

10.3390/ma12142220 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2220 ◽

Cited By ~ 8

Author(s):

Xiaohu Wang ◽

Yu Peng ◽

Jiyang Wang ◽

Qiang Zeng

Keyword(s):

Computed Tomography ◽

Pore Structure ◽

High Mass ◽

X Ray ◽

Quantitative Evidence ◽

Mercury Intrusion ◽

Pore Size Distributions ◽

Cement Based Materials ◽

Before And After ◽

X Ray Computed

Mercury intrusion porosimetry (MIP) is questioned for possibly damaging the micro structure of cement-based materials (CBMs), but this theme still has a lack of quantitative evidence. By using X-ray computed tomography (XCT), this study reported an experimental investigation on probing the pore structure damages in paste and mortar samples after a standard MIP test. XCT scans were performed on the samples before and after mercury intrusion. Because of its very high mass attenuation coefficient, mercury can greatly enhance the contrast of XCT images, paving a path to probe the same pores with and without mercury fillings. The paste and mortar showed the different MIP pore size distributions but similar intrusion processes. A grey value inverse for the pores and material skeletons before and after MIP was found. With the features of excellent data reliability and robustness verified by a threshold analysis, the XCT results characterized the surface structure of voids, and diagnosed the pore structure damages in terms of pore volume and size of the paste and mortar samples. The findings of this study deepen the understandings in pore structure damages in CBMs by mercury intrusion, and provide methodological insights in the microstructure characterization of CBMs by XCT.

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Changes in Denitrification Potentials and Riverbank Soil Bacterial Structures along Shibetsu River, Japan

Applied and Environmental Soil Science ◽

10.1155/2018/2530946 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9

Author(s):

Yoshitaka Uchida ◽

Hirosato Mogi ◽

Toru Hamamoto ◽

Miwako Nagane ◽

Misato Toda ◽

...

Keyword(s):

Bacterial Community ◽

Inorganic Nitrogen ◽

Anaerobic Incubation ◽

Community Structures ◽

Bacterial Response ◽

Glucose Carbon ◽

Soil Ecosystems ◽

Increase Rate ◽

Before And After ◽

C And N

Riverbank soil ecosystems are important zones in terms of transforming inorganic nitrogen (N), particularly nitrate (NO3−-N), in soils to nitrous oxide (N2O) gases. Thus, the gasification of N in the riverbank soil ecosystems may produce a greenhouse gas, N2O, when the condition is favourable for N2O-producing microbes. One of the major N2O-producing pathways is denitrification. Thus, we investigated the denitrification potentials along Shibetsu River, Hokkaido, Japan. We sampled riverbank soils from eight sites along the Shibetsu River. Their denitrification potentials with added glucose-carbon (C) and NO3−-N varied from 4.73 to 181 μg·N·kg−1·h−1. The increase of the denitrification after the addition of C and N was negatively controlled by soil pH and positively controlled by soil NH4+-N levels. Then, we investigated the changes in 16S rRNA bacterial community structures before and after an anaerobic incubation with added C and N. We investigated the changes in bacterial community structures, aiming to identify specific microbial species related to high denitrification potentials. The genus Gammaproteobacteria AeromonadaceaeTolumonaswas markedly increased, from 0.0 ± 0.0% to 16 ± 17%, before and after the anaerobic incubation with the excess substrates, when averaged across all the sites. Although we could not find a significant interaction between the denitrification potential and the increase rate of G. AeromonadaceaeTolumonas, our study suggested that along the Shibetsu River, bacterial response to added excess substrates was similar at the genus level. Further studies are needed to investigate whether this is a universal phenomenon even in other rivers.

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A Bayesian Analysis of the Inversion of the SARS-COV-2 Case Rate in the Countries of the 2020 European Football Championship

10.20944/preprints202108.0111.v2 ◽

2021 ◽

Author(s):

Luca Casini ◽

Marco Roccetti

Keyword(s):

Bayesian Analysis ◽

Linear Model ◽

Generalized Linear Model ◽

Piecewise Regression ◽

Increase Rate ◽

Before And After ◽

Case Rate ◽

European Football

While Europe was beginning to deal with the resurgence of COVID-19 due to the Delta variant, the European football championship took place, June 11 - July 11, 2021. We studied the inversion in the decrease/increase rate of new SARS-COV-2 infections in the countries of the tournament, investigating the hypothesis of an association. Using a Bayesian piecewise regression with a Poisson Generalized Linear Model, we looked for a changepoint in the timeseries of the new SARS-COV-2 cases of each country, expecting it to appear not later than two to three weeks after the date of their first match. The two slopes, before and after the changepoint, were used to discuss the reversal from a decreasing to an increasing rate of the infections. For 17 out of 22 countries (77%) the changepoint came on average 14.97 days after their first match [95% CI 12.29 to 17.47]. For all those 17 countries, the changepoint coincides with an inversion from a decreasing to an increasing rate of the infections. Before the changepoint, the new cases were decreasing, halving on average every 18.07 days [95% CI 11.81 to 29.42]. After the changepoint, the cases begin to increase, doubling every 29.10 days [95% CI 14.12 to 49.78]. This inversion in the SARS-COV-2 case rate, happened during the tournament, provides evidence in favor of a relationship

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Composition Materials With Metal Matrix Condensed from the Vapor Phase

Journal of Material Science and Technology Research ◽

10.31875/2410-4701.2021.08.4 ◽

2021 ◽

Vol 8 ◽

pp. 24-29

Author(s):

N.I. Grechanyuk ◽

V.G. Grechanyuk ◽

A.F. Manulyk

Keyword(s):

Porous Materials ◽

Vapor Phase ◽

Metal Matrix ◽

Open Porosity ◽

Deposition Temperature ◽

Second Phase ◽

Pore Sizes ◽

Phase Concentration ◽

Composition Materials ◽

Condensed Materials

In this article, the present-day problems of microporous condensed materials obtained from the vapor phase are discussed. The pore sizes are regulated by the amount of the second phase concentration and the deposition temperature. The oxides, fluorides, and sulfides can be used as the second phase and non-removable inclusions. The open porosity can be regulated from 0% to 50 %of the porosity and with average porose sizes of 0.1 to 8 µm. The condensed micro-porous materials can be deposited in coating form or the form of massive bulk sheet materials with a thickness of up to 6 mm and a diameter of 1m.

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Effects of Neutron, Ion and Proton Irradiation on Nano-Indentation Hardness of RPV Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.999.39 ◽

2020 ◽

Vol 999 ◽

pp. 39-46

Author(s):

Cheng Liang Li ◽

Guo Gang Shu ◽

Jing Li Yan ◽

Wei Liu ◽

Yuan Gang Duan

Keyword(s):

Proton Irradiation ◽

Indentation Hardness ◽

Irradiation Embrittlement ◽

Irradiation Hardening ◽

Nano Indentation ◽

Rpv Steel ◽

Hardness Tests ◽

Increase Rate ◽

Before And After ◽

Reactor Pressure

The irradiation embrittlement damage of reactor pressure vessel (RPV) steel is one of its primary failure mechanisms. In this work, neutron, ion and proton irradiation experiments were carried on the same commercial RPV steels with the same irradiation fluence under the same temperature of 292°C. Then the nano-indentation hardness tests were performed on the RPV steel before and after irradiation. The results show that the irradiation hardening effects are observed by means of nano-indentation technique under the above three irradiations, and the hardening features are basically the same. While the max variation and increase rate are obviously different between those irradiations. It is found that the main reason of the above differences are caused by different energies of irradiation energetic particles, resulting in different types and quantities of defects. The conclusions in this paper are helpful to select and compare different irradiation experiments to the research of RPV steels irradiation embrittlement damage.

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Characterization of cordierite-mullite ceramics prepared from natural raw materials

Acta Chimica Slovaca ◽

10.2478/acs-2013-0001 ◽

2013 ◽

Vol 6 (1) ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Abdulmula Ali Albhilil ◽

Martin Palou ◽

Jana Kozánková

Keyword(s):

Thermal Shock Resistance ◽

Raw Materials ◽

X Ray Diffraction ◽

X Ray ◽

Mercury Intrusion ◽

Before And After ◽

Shock Resistance ◽

Quenching Method ◽

Mullite Ceramics

Abstract Series of six cordierite-mullite ceramics were synthesized via solid state reaction at various temperatures from 1250 °C for pure cordierite to 1500 °C for pure mullite. Then the samples were submitted to the test of thermal shock resistance based on cycling heating-quenching procedure. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Mercury intrusion porosimeter (MIP) have been used to characterize the samples before and after cycling heating-quenching method. Sample 6 was broken after 35 heating-quenching cycles, while the five other reminded stable. The refractoriness of samples is found to be higher than that of commercial ones. XRD shows that heating-quenching procedure has led to crystallization of cordierite and mullite phases. Apart from sample 6, the pore structure is stable with slight consolidation. The microstructure images confirm the results of XRD and MIP showing crack in sample 6 only, but compact and larger particles resulting from crystal growth in other samples due to the repeated action of heating.

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Investigation on the pore characteristics of coal specimens with bursting proneness

Scientific Reports ◽

10.1038/s41598-019-52917-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Yutao Li ◽

Yaodong Jiang ◽

Bo Zhang ◽

Honghua Song ◽

Wenbo Dong ◽

...

Keyword(s):

Uniaxial Compression ◽

Nitrogen Adsorption ◽

Pore Characteristics ◽

Pore Connectivity ◽

Mercury Intrusion ◽

Compression Failure ◽

Pore Compressibility ◽

Before And After ◽

Compressibility Coefficient ◽

Insight Into

Abstract To achieve further insight into the pore characteristics, the coal specimens with different bursting proneness before and after uniaxial compression failure are tested and compared in this paper. The data of mercury intrusion test is corrected by that of low-temperature nitrogen adsorption and desorption test (LTNAD). The pore size distribution and pore volume of specimens are obtained. The pore compressibility coefficient is determined based on the fractal dimension of pore. Scanning electron microscope (SEM) and computed tomography (CT) are combined to evaluated the pore connectivity. The value of pore compressibility coefficient of specimens with high bursting proneness is larger than that of medium bursting proneness. It means more compressibility and abrupt failure under stress. The researches of both SEM and CT indicate that the pore connectivity of specimens with medium bursting proneness is better. The results show that great differences exist in the pore characteristics of specimens with high and medium bursting proneness, and uniaxial compression failure exacerbates the complexity of pore characteristics.

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