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Interaction Between Soil Particles and Soil Solution
Published in Shingo Iwata, Toshio Tabuchi, Benno P. Warkentin, Soil-Water Interactions, 2020
Shingo Iwata, Toshio Tabuchi, Benno P. Warkentin
Entropy values have been obtained for other zeolites using the same techniques (Johnson et al., 1983, 1985). The average standard molar entropies of zeolitic water are shown in Table 2.7, together with the amounts of zeolitic water, the cation exchange capacities estimated from the chemical compositions and the entropies of liquid water, ice and water vapor at 25°C. The cation exchange capacities are very large, and the zeolitic water contents are low. The entropy values of heulandite and analcime are considerably larger than those of natrolite and scolecite. Though the authors did not discuss the differences, the larger cation exchange capacities of the latter may be the reason. Furthermore, it is interesting that the entropy values of natrolite (Na2Al2Si3·2H2O) and scolecite (CaAl2Si3O10·3H2O) are identical, while the counter ion is different. Zeolitic water is held in the very small channels of zeolite with a diameter of the order of several angstroms. This means that a zeolitic water molecule in a channel is under a large potential field due to intermolecular forces acting between the channel wall and the water molecule. In addition, the water molecule is adsorbed by a counter ion coexisting there, and may have a chemical interaction with an oxygen atom on the wall.
Thermal Properties of CSPMs
Published in Yu. I. Aristov, Nanocomposite Sorbents for Multiple Applications, 2020
The effective heat capacity of water in the hydrated composite was found to be close to that for mineral zeolites containing molecular water—analcime NaAlSi2O6·H2O [17] and paranatrolite Na2Al2Si3O10·3H2O [18]—and sufficiently differs from that for bulk water and ice (Fig. 10.3). The effective heat capacity of water in the hydrated composite is larger than the heat capacity of bulk ice and is significantly smaller than that of liquid water. Hence, the water molecules in the salt dihydrate are more mobile than in the bulk ice.
Online quality control of aggregates based on the measurement of magnetic susceptibility
Published in Vladimir Litvinenko, Topical Issues of Rational Use of Natural Resources 2019, 2019
C. Weigel, K.C. Vogler, A. Ploch, H. Tudeshki
The open pit mining in a nepheline basalt is typical for mining operations in alkali basalt, which often have a problem with structural stability in the form of sunburn. This effect is caused by feldspar representatives such as nepheline and leucite, which only occur in SiO2-sub-saturated alkaline rocks. The water absorption of the rock results from the hydrothermal over weathering formation of minerals of the zeolite group (analcime) from primary magmatic nepheline. This is accompanied by a volume increase of up to 5%. The increase in volume results in the loss of structure of the rock. With this rock, the applicability of the magnetic susceptibility method is limited and must be supplemented by other measuring methods (Weigel et al. 2019).
Synergic effect of some waste pozzolans on the mechanical and shielding properties of geopolymer concretes
Published in Radiation Effects and Defects in Solids, 2023
Barış Bayrak, Ali Öz, Esra Kavaz, Gökhan Kaplan, Oğuzhan Çelebi, Haluk Görkem Alcan, Abdulkadir Cüneyt Aydın
Similar images were obtained for QP as seen in Figure 15. Air voids of approximately 50 µm in size were observed in the M3 mixture. Relatively larger air voids were observed as MK reduced machinability. Map cracks of 1 µm width were observed in the geopolymer matrix. These cracks were observed especially in the regions where the QP was separated from the matrix. The spherical particle structure of QP caused its surface to be smooth. Therefore, the strength of the matrix is considerably reduced. The MK used in the M3 mixture caused the formation of analcime (NaAlSi2O6·H2O) in the matrix. Analcime is a zeolitic geopolymerization product. Similar findings were also observed in the XRD analysis. Analcime is formed by the reaction of especially clay compounds in an alkaline environment.