Papers by Keyword: Pore Distribution

Abstract: The escalating levels of atmospheric carbon dioxide (CO₂) emissions and the consequential threat of global warming necessitate urgent measures for CO₂ reduction. This study explores the development of CO₂ adsorbents from biomass, specifically charcoal derived from empty palm bunches, focusing on the impact of different activating agents and activation temperatures on their properties. The research methodology involves the hydrothermal carbonization of empty palm fruit bunches followed by activation using three different materials: potassium hydroxide (KOH), urea, and a combination of KOH and urea, at three distinct activation temperatures (180°C, 200°C, and 220°C). The investigation encompasses a comprehensive analysis of the functional groups and surface morphology through Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The findings demonstrate that the choice of activating agent and activation temperature significantly influences the characteristics of the resultant charcoal. Notably, higher activation temperatures lead to reduced lignin content and increased pore distribution. Among the various combinations, the KOH + Urea activating agent at 220°C exhibits the most favorable attributes, including the weakest lignin peak intensity and the highest pore distribution. In conclusion, this research underscores the potential of empty palm bunch charcoal as a promising CO₂ adsorbent, offering insights into optimized conditions for its production. This contributes to the ongoing global efforts to combat climate change by mitigating CO₂ emissions.

Abstract: From the viewpoint of effective utilization of industrial wastes and reduction of CO₂ emission, the use of concrete mixed with blast furnace slag and fly ash has been promoted. However, the durability of fly ash concrete using blast furnace slag cement has not been clarified enough. About chloride attack, the resistance against the penetration of chloride ions could be improved due to the dense pore structure formed by the synegetic effect of mixing both ground granulated blast-furnace slag and fly ash into concrete. In this study, resistance performance of concrete using both blast furnace slag cement and fly ash against chloride attack and carbonation was experimentally investigated. The relationship between such resistance performance and pore structure of the concrete was also examined. As a result, the combination of blast furnace slag cement and fly ash type II resulted in the decrease of pore volume over 50 nm in the diameter and reduction of the apparent diffusion coefficient of chloride ion, but the resistance performance against carbonation of the concrete was lower than the case of the normal fly ash concrete.

Abstract: Physico-chemical characteristics impact directly or indirectly the bioactive properties of biomaterials, it is then essential to correlate it with their effect in vivo. A panel of biomaterials available on the market, based on Hydroxyapatite (HA) and Tricalcium phosphate (β-TCP) is studied in terms of surface area, hydrophilicity, porosity, zeta potential, crystalline phases and density. This study highlights the dispersity of commercial calcium phosphates (CaP) properties, and demonstrates how the quality criteria required for such bone substitute based on biomimicry concept, whose pores distribution is certainly the more relevant, are often incompletely or not respected according to literature.

Abstract: The pore characteristics of saturated clay sourced from microstructure pictures in Pearl River Delta region of south China is analyzed considering the microstructure in different sample sections. The histogram statistics are compared with each other by pore data in terms of the size, the shape and the arrangement of link status. The repercussions of including the anisotropy ratio law of pore characteristics are focused to study saturated clay. It is found that the analysis considering anisotropy ratio results in consolidation by pore distribution based on saturated clay microstructure. The soil porosity of horizontal section was larger than that of vertical section. Vertical section status induced the directional property, and it would be presented directional probability entropy which is able to calculating the chaos of overall arrangement which is a lower value because of directional property.

Abstract: Base on the microscopic structure is characterized by anisotropy of microstructure that inherent in the process of saturated soft clay with sedimentary primary anisotropy or external force caused by induced anisotropy, biological changes along with the trend of the minimum potential energy. By studying the spindle rotation stress characteristics of the soil of the microscopic distribution, the pore characteristics of saturated clay sourced from microstructure pictures in Pearl River Delta region of south China is analyzed considering the microstructure in different stress conditions. Microstructure distribution of soft clay under conditions of section profiling variation including the anisotropy ratio law of pore characteristics are focused to study saturated clay. It is found that major-minor axis status induced the directional property of saturated soil in the process of consolidation by vacuum preloading. And porosity shapes factors which are small indicate directional property would be probability entropy which is able to calculating the chaos of overall arrangement, and it will be a lower value because of directional property. It is apparently inconsistent with the pore distribution of saturated clay which results from the cut section of different point of angle. And horizontal joint and large pore space constitute one of the saturated clay structure characteristic, which related to different pressures.

Abstract: The pore distribution of low silica sinter ore samples with different alkalinity was measured by pressure mercury, and the fractal characteristic of pore distribution was calculated with multifractal theory, then metallurgical properties were also obtained, finally, their connection among them was discussed. The results showed that the pore distribution has experienced a process from non-uniform to uniform with increasing alkalinity. When the alkalinity was 2.0, the spectral width Δα was minimum, multifractal structure was more uniform, fractal characteristics was better, in the meantime, the pore distribution was more uniform, and the pores were larger, which improved metallurgical properties. The results also showed that when the alkalinity was 2.0, its metallurgical properties was optimal.

Abstract: Experimental materials in this paper are taken from songyue temple and fawang temple which are both in henan province, X ray fluorescence analysis method is adopted to analysis the chemical ingredients of the historical bricks come from two temples respectively; strength of the bricks come from two temples are compared also; then a model of porous bodies connected parallel is established to reflect the pore distribution of material, the qualitative relationship between strength of material and porosity/pore distribution is derived; mercury intrusion method is used at last to get the porosity and pore microproperties of the historical bricks come from two temples, results show that porosity and microproperties of pores are important factors that affect the characteristics of historical brick material.

Abstract: In this study, the production of β-Si6-zAlzOzN8-z (z =3) powders by the carbothermal reduction and nitridation of kaolin (Al2O3.2SiO2.2H2O) of Turkish origin (Can-Canakkale) was carried out with different processing parameters. It was found that the morphology of the produced SiAlON powder was mixture of irregular and whisker like grains. Therefore this morphology is suitable for liquid metal infiltration since the powders are already high porous. The kaolin powder containing stoichiometric rate carbon black and 30 % charcoal were pressed and reacted under nitrogen flow (2 lt/min) between 1400-1475°C for 4 h. After a carbothermal reduction and nitridation (CRN) process, porous β- SiAlON ceramic was produced from natural kaolin. Residual carbon and charcoal in the produced ß-SiAlON ceramic were fired at 1000°C giving extra porosity. The porous ß-SiAlON ceramics were sintered under N2 atmosphere at 1550°C for 2 h to make preform for infiltration process. SEM image analyses were carried out to determine preform and pore morphology and XRD analysis were performed for phase transformation.