Scanning electron microscope (SEM) observations of both materials highlighted the more homogeneous aspect of sodium bentonite, while calcium bentonite exhibited more void spaces in its structure. ... As revealed by TEM observations, the Ca-bentonite texture appears to be heterogeneous (Fig. 6). The material is mainly constituted of aggregates ...
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The spatial arrangement of sand grains and bentonite fabric at different hydration states was observed with environmental scanning electron microscopy (ESEM) and field emission scanning electron ...
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Furthermore, most observational studies are based on before-and-after images with little sense of the pace of crack closure. This paper reports a set of x-ray computerised tomography observations of a single artificial cylindrical hole, as a proxy for a crack, in consolidated, close-to-saturation bentonite samples, undergoing further hydration.
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Therefore, observations of the microstructure of compacted bentonite have been extensively performed using transmission electron microscopes (TEMs) and/or scanning electron microscopes (SEMs). Additionally, theoretical models for the microstructure of bentonite have been established (Pusch and Yong, 2006). However, further detailed knowledge of ...
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These observations on the chemically induced changes of the pore structure of the MX-80 B/S mixtures are in agreement with the findings in Mata (2003) who concluded that saline water has a significant influence on the macropores of bentonite-based mixture materials, whereas its effect on the micro-pores is not significant.
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The following conclusions were obtained through this study. (i) The swelling characteristics of sand-bentonite mixtures is dependent on the dry density and bentonite content of mixtures. (ii) From observation with the scanning electron microscope, we found that the voids of mixtures are filled up by the volume increase when bentonite absorbs water.
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and hydraulic conductivity of bentonite based buffer and backfill materials. They also observed the swelling behavior of bentonite by using scanning electron microscope which can control the temperature and vapor pressure around samples. From the observed results, it was found that the voids in the material were
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In fact, pores of such large size were not observed in the cryo-FIB–SEM observations on bentonite; our plunge frozen bentonite samples show no eutectic microstructure and they look similar to those of the high pressure frozen samples of Holzer et al. (2010). In particular, the cryo-SEM images of bentonite show the presence of very thin ...
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Clay has wide application in engineered barriers. However, it is prone to crack if moisture content decreases at most circumstances. This research aimed to microscopically study drying shrinkage and associated cracking of two different clays: kaolin and sodium-based bentonite, using optical microscope-Leica DM2700 M, under controlled condition.
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Article "Observation of swelling behavior of bentonite by new electron microscope." Detailed information of the J-GLOBAL is an information service managed by the Japan Science and Technology Agency (hereinafter referred to as "JST"). It provides free access to secondary information on researchers, articles, patents, etc., in science and technology, medicine and …
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Recently, transmission X-ray microscopy (TXM) has been employed in an attempt to resolve the three-dimensional structure of montmorillonite in water [34], [35].Although this technique allows the direct observation in the hydrated state, it is limited to a spatial resolution of 50–60 nm.This is therefore inappropriate to study the arrangements between montmorillonite …
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Download scientific diagram | Material properties of kaolin and bentonite from publication: Microscope observation of cracks of clay | Clay has wide application in engineered barriers. However, it ...
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Microscope observation of cracks of clay. Chen Liang 1, Yilin Gui 1 * and Cees van der Land 2. 1 Newcastle University, School of Engineering, Newcastle upon Tyne, United Kingdom ... kaolin and sodium-based bentonite, using optical microscope-Leica DM2700 M, under controlled condition. The samples used were cylindrical with 20mm in diameter and ...
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A dry polishing technique was used to form a smooth surface that well shows the original microstructure of bentonite ores, allowing petrographic discussion as in the observation of non-clayey rocks. Besides coarse quartz (probably pyroclastic origin), fine silica with grain sizes ranging from a few microns to submicron is widely observed in ...
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Bentonite occurrence has also been reported in Benue State, (Abdullahi, 1996) in Azara; Nasarawa State and Akiri Hill in Plateau state (Onaogu, 1996). Scanning electron microscopy is best suitable for observation of bentonite structure. The resolution is not good enough to allow observation of single clay mineral grains.
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The direct observation through membrane (DOTM) technique has been used to visualise the fouling on flat-sheet membranes in crossflow modules [6].This setup allows the visualisation of particles larger than 1 μm and consists of a microscope, a camera and a membrane module.The microscope objective lens is focussed on the permeate side of a …
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However, it is necessary to choose the appropriate bentonite from among many kinds of bentonite in the design of buffer and backfill materials. To do this, the writers have …
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The microstructural evolution and hydraulic conductivity of bentonite in NaCl solution is investigated by in situ laser scanning microscopy (LSM). Upon exposure to saline solution, the bentonite aggregate swells rapidly, followed by a longer period of more gradual swelling.
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Then, the microstructure of the bentonite was examined using scanning electron microscopy (SEM) both before and after conducting the expansion test. ... This observation suggests that the samples in the initial stage exhibit a slow expansion within a short duration upon contact with water; The sample undergoes rapid water absorption in the ...
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The bentonite was mixed with sand at bentonite ratios (dry wt%) of 30 % and 100 % (no sand blend), ... Microscope observation. The SEM micrographs of the middle and bottom parts of the specimens immersed in the alkaline solutions are shown in Fig. 12. Aggregations of montmorillonite were observed in each part of the specimens under all conditions.
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Direct observation (DO) technique allowed the visualisation of fouling deposition and removal in real time and in a non-invasive manner. The DO setup was relatively simple and featured a crossflow hollow fibre membrane module, a microscope and a
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2008. Direct observation (DO) technique allowed the visualisation of fouling deposition and removal in real time and in a non-invasive manner. The DO setup was relatively simple and featured a crossflow hollow fibre membrane module, a microscope and a video camera.
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la bentonite compacte sous gonflement libre sont étudiées lors du mouillage et du séchage. Pour l'observation de la microstructure, on utilise la porosimétrie à intrusion de mercure (MIP) et le …
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We first presented a 3-D microscope observation by a confocal laser scanning microscope (CLSM) of bentonite to specify local geometrical characteristics. Second, we …
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Colloids and Surfaces A: Physicochem. Eng. Aspects 262 (2005) 14–22 ESEM observations of compacted bentonite submitted to hydration/dehydration conditions G. Montes-H a,∗, Y. Geraud b, J. Duplay a, T. Reuschlé c a UMR 7517 ULP-CNRS, CGS 1, Rue Blessig, F-67084 Strasbourg, France UMR 7516 ULP-EOST, IPG 1, Rue Blessig, F-67084 Strasbourg, France …
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Article "Observation of swelling behavior of bentonite by new electron microscope." Detailed information of the J-GLOBAL is an information service managed by the Japan Science and …
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These bentonite layers can effectively prevent groundwater from flowing into the waste-holding canister and isolate it from the surrounding ... Environmental scanning electron microscope (ESEM) observations were performed (Sun et al., ... (intra-aggregate pores). This observation is corroborated by a number of results from the literature, ...
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Bentonite is considered a great candidate as an adsorbent material for heavy metal ions such as Pbin aqueous solution due to its typically elevated surface ... All observations of Arctic warming can be accounted for as consequences of these flows of warm water to the Arctic. ... Current Microscopy Contributions to Advances in Science and ...
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Environmental Scanning Electron Microscope (ESEM) was used for microstructure observation, the primary advantage of this technique compared to conventional Scanning Electron Microscope (SEM) being that the ESEM does not require the soil sample to be initially lyophilized (Doehne and Stulik, 1990). Four samples were observed at ESEM: powder ...
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This research aimed to microscopically study drying shrinkage and associated cracking of two different clays: kaolin and sodium-based bentonite, using optical microscope-Leica DM2700 …
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Microscope observation of cracks of clay Chen Liang1,Yilin Gui1,*, Cees van der Land2 1Newcastle University, School of Engineering, ... In the laboratory, kaolin and bentonite powder are
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The natural bentonite exhibits a specific surface area of 23.5 m 2 /g and a CEC value of 47.7 mEq/100 g and displays a higher adsorption capacity of all heavy metals in both single and …
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Transmission and scanning electron micrographs of Umiat bentonite revealed thin, mica-like grains with irregular shapes. Most of the bentonite showed electron diffraction ring patterns, …
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Liang, Chen, Gui, Yilin, & van der Land, Cees (2019) Microscope observation of cracks of clay. In Ibraim, Erdin & Tarantino, Alessandro (Eds.) Proceedings of the 7th International Symposium on Deformation Characteristics of Geomaterials (IS-Glasgow 2019) (E3S Web of Conferences, Volume 92). ... kaolin and sodium-based bentonite, using optical ...
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Bentonite, with primary component of montmorillonite, is the most used material for the preparation of water-based drilling fluid in the petroleum industry [5], [6]. ... (XRD), and scanning electron microscope (SEM) observation provides the understanding related to the interaction between bentonite particles and filtration reducers. This study ...
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Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were used to observe the surface microscopic morphology of the original and alkaline-corroded bentonite.
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(ii) From observation with the scanning electron microscope, we found that the voids of mixtures are filled up by the volume increase when bentonite absorbs water.
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The bentonite surfaces were studied using a thorough scanning electron microscopy exploration and analysed using an energy-dispersive X-ray detector (SEM-EDX). ... SEM observations allow defining morphologies at the μm size range, such as the aggrupation of particles to form aggregates. ... Bentonite is a cornerstone barrier for the isolation ...
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Bentonite and bentonite/sand mixtures are selected primarily because of their low hydraulic permeability in a saturated state. This ensures that diffusion will be the dominant transport mechanism ...
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This research aimed to microscopically study drying shrinkage and associated cracking of two different clays: kaolin and sodium-based bentonite, using optical microscope …
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