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Number of results: 5
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Abstract

Microporous carbon molecular sieves of extremely narrow pore size distribution were obtained by carbonization of a novel raw material (Salix viminalis). The precursor is inexpensive and widely accessible. The pore capacity and specific surface area are upgradable by H3PO4 treatment without significant change of narrowed PSD. The dominating pore size indicates that these molecular sieves are a potential competitor to other nanoporous materials such as opened and purified carbon nanotubes.

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Authors and Affiliations

Jerzy Łukaszewicz
Krzysztof Zieliński
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Abstract

The objective of this study is to analyze effect of ground granulated blast furnace slag (GGBFS) in concrete on the pore structure, this research will contribute to the knowledge regarding the use of GGBFS as a cementitious material in terms of the future reference and potential improvement to the properties of concrete. To this aim, on the one hand a control specimens (CS) and another samples with 40% and 60% of GGBFS as replacement cement with moist cured at 20oC, 27oC, and cured at site. The compressive strength and the Mercury intrusion porosimetry (MIP) test were done. The result indicates that the strength of concrete with GGBFS at early ages tend to be lower in comparison with the CS. However, the GGBFS reaction plays important roles at the later ages. The samples cured at higher temperature produce higher strength value. The total pore volume (TPV) of the concrete use GGBFS decreases with increasing age.
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Authors and Affiliations

Abdul Chalid
1

  1. Senior Lectures Post Graduate of Civil Eng. Sangga Buana University, Jalan Surapati No. 189 Bandung-West Java 40123, Indonesia
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Abstract

The paper presents research on the influence of grain size of selected coals and their structural parameters on the diffusion coefficient and methane sorption isotherms. Two coals from Polish hard coal mines, differing in the coal rank, were tested. Sorption isotherms for methane were determined. An unconventional sequence of pressures 0→0.1→0→0.5→0→1.5 MPa was employed to assess the speed of achieving sorption equilibrium at different pressures. The studies of CH4 accumulation kinetics were performed on various grain classes of the tested coals. Both the sorption capacity of coal and the diffusion coefficient proved to be highly sensitive to the experimental methodology. Critical measurement parameters in terms of determining the diffusion coefficient concerning the assumptions of the Crank model were indicated. The influence of the equivalent radius of coal grain on the process kinetics was demonstrated. The stepwise pressure increase factor was examined in the context of minimising the impact of sorption isotherm non-linearity on the results. The importance of the width of the grain class of coals was determined to reduce their maceral inhomogeneities. These factors are the most common reason that makes it difficult to quantitatively compare diffusion coefficient values.
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Authors and Affiliations

Katarzyna Kozieł
1
ORCID: ORCID
Aleksandra Gajda
1
ORCID: ORCID
Marta Skiba
1
ORCID: ORCID
Norbert Skoczylas
2
ORCID: ORCID
Anna Pajdak
1
ORCID: ORCID

  1. Strata Mechanics Research Institute of the Polish Academy of Sciences, 27 Reymonta Str., 30-059 Kraków, Poland
  2. AGH University of Kraków, Facu lty of Geology, Geoph ysics and Environmental Protection,al. Mick iewicza 30, 30-059 Kraków, Poland
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Abstract

In this study, a SUS316L membrane having double layered pore structures was fabricated, and the pore characteristics were analyzed after coating with a spherical powder and a flake-shaped powder on a disk-shaped SUS316L support using a wet powder spraying process. The thickness of the coated layer was checked using an optical microscope, and air permeability was measured using a capillary flow porometer. When the coating amount was similar, the fine porous layer prepared using flake powder was thicker and showed higher porosity. In the case of a similar thickness, the case of using flake powder was half of the amount of spherical powder used. Therefore, it was confirmed that it is possible to manufacture a metal membrane having a high filter efficiency even with a small coating amount when using the flake powder.
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Authors and Affiliations

Min-Jeong Lee
1 2
ORCID: ORCID
Hyeon-Ju Kim
1
ORCID: ORCID
Manho Park
3
ORCID: ORCID
Jung-Yeul Yun
1
ORCID: ORCID

  1. Korea Institute of Materials Science (KIMS), Metal Powder Department, Changwon 51508, Republic of Korea
  2. Pusan National University Department of Materials Science and Engineering, Republic of Korea
  3. R&D Center, ASFLOW Co. Ltd, Suwon, Republic of Korea
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Abstract

In this study, a flake-shaped metal powder was coated on a tube shaped pre-sintered 316L stainless steel support using a wet powder spraying process to fabricate a double pore structure, and the pore characteristics were analyzed according to coating time and tube rotation speed. The thickness of the coated layer was checked via optical microscopy, and porosity was measured using image analysis software. Air permeability was measured using a capillary flow porometer. As a result of the experiment, the optimal rotation speed of the support tube was established as 200 rpm. When the rotation speed was fixed, the coating thickness and the coating amount of the double pore structure increased as the coating time increased. The porosity of the double pore structure was increased due to the irregular arrangement of the flake-shaped powder. The air permeability of the double pore structure decreased with increasing fine pore layer thickness.
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Authors and Affiliations

Min-Jeong Lee
1 2
ORCID: ORCID
Yu-Jeong Yi
1 2
ORCID: ORCID
Hyeon-Ju Kim
1
ORCID: ORCID
Manho Park
3
ORCID: ORCID
Jungwoo Lee
2
ORCID: ORCID
Jung-Yeul Yun
1
ORCID: ORCID

  1. Korea Institute of Materials Science (KIMS), Metal Powder Department, Changwon, 51508, Republic of Korea
  2. Pusan National University, Department of Materials Science and Engineering, Busan, 46241, Republic of Korea
  3. R&D Center, ASFLOW Co. Ltd, Hwasung, 16648, Republic of Korea

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