The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Michael D. Higgins - One of the best experts on this subject based on the ideXlab platform.
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Inherited correlation in Crystal Size distribution: COMMENT
Geology, 2002Co-Authors: Bruce D. Marsh, Michael D. HigginsAbstract:The results and conclusions in the recent paper by [Pan (2001)][1] are based on an inadequate understanding of the concept and measurement of population density and the fundamentals of the method of Crystal Size distributions. Not only does Pan perform his example calculations incorrectly, which
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measurement of Crystal Size distributions
American Mineralogist, 2000Co-Authors: Michael D. HigginsAbstract:Studies of Crystal Size distributions (CSD) can reveal much about how rocks solidify and under what conditions. Data from two-dimensional sections can be readily acquired at many different scales, from electron microscope images, thin sections, slabs, outcrops, and so on, but the conversion to true, three-dimensional values is complex. The widely used Wager method does not have a good theoretical basis and does not give accurate results. A modification of the Saltikov correction method is proposed here that is more accurate and can account for different Crystal shapes and fabrics. Population densities determined by this method differ by factors of 0.02 to 100 from those determined by the Wager method. Published CSDs determined using other methods can be recalculated if the Crystal shape and fabric parameters can be estimated. The method has been incorporated into a new program, CSDCorrections.
Ting Y. Lee - One of the best experts on this subject based on the ideXlab platform.
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Transient Crystallization and Crystal Size Distribution of Zeolite A
Chemical Engineering Science, 1993Co-Authors: Wen H. Chen, Ting Y. LeeAbstract:The transient Crystallization and the Crystal Size distribution of zeolite A have been correlated successfully by a set of modified population balance equations. The zeolite A Crystal growth reaction under hydrothermal synthesis condition without any hydrodynamic influence was shown to be the controlling step. Experimental results from nucleation to the completion of Crystallization as well as the corresponding Crystal Size distributions were presented. Both reaction and mass transfer mechanisms were studied and compared.
Jonas Hedlund - One of the best experts on this subject based on the ideXlab platform.
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yield of gasoline range hydrocarbons as a function of uniform zsm 5 Crystal Size
Catalysis Communications, 2011Co-Authors: Ali A Rownaghi, Fateme Rezaei, Jonas HedlundAbstract:Abstract Uniform ZSM-5 nanoCrystals were syntheSized by a single-templating procedure. The samples were then characterized by a variety of physical techniques such as XRD, SEM, BET, ICP and TPD. The dehydration of methanol over syntheSized ZSM-5 zeolite was studied in a fixed-bed continuous flow reactor at 370 °C and WHSV of 2.6 gg −1 h under ambient pressure. The effect of Crystal Size of zeolite catalysts on product distribution in methanol dehydration reaction was investigated. Good correlation was observed between catalytic performance, product distribution and Size of ZSM-5 Crystals. It was found that the decrease in Crystal Size significantly influences light olefins (ethylene and propylene) and paraffins (C 1 –C 4 ) selectivity in methanol dehydration reaction. Furthermore, nanoCrystal ZSM-5 showed long-term catalytic stability compared with conventional ZSM-5 provided that the reaction activity is strongly dependent on the Crystal Size in methanol dehydration process. The results indicated that Crystal Size significantly affects the catalyst lifetime and hydrocarbon distributions in product stream. Based on the obtained results, it is concluded that the use of uniform ZSM-5 nanoCrystals improves the yield of propylene and alkyl aromatics in methanol conversion reaction at mild conditions.
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Silicalite-1 membranes with small Crystal Size
Studies in Surface Science and Catalysis, 2004Co-Authors: Charlotte Andersson, Jonas Hedlund, Fredrik Jareman, Johan SterteAbstract:Abstract Silicalite-1 membranes with small Crystal Size were prepared using a multiseeding method, were the support was repeatedly seeded and exposed to a short hydrothermal treatment up to five times. The films were characterized using SEM, single gas permeation, porosimetry and mixture separation experiments. Films with three or four layers were of high quality i.e with minor defects according to the porosimetry experiments but showed poor separation of binary mixtures. This result may be attributed to the small Crystal Size and/or large amount of grain boundaries in the films.
Yucheng Pan - One of the best experts on this subject based on the ideXlab platform.
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Inherited correlation in Crystal Size distribution
Geology, 2001Co-Authors: Yucheng PanAbstract:Crystal Size distribution analysis has been applied extensively to chemical engineering and geosciences. Here I show that Crystal Size distribution analysis is based on the inherited correlation of −3ln( L ) versus L , where L is Crystal Size and is therefore flawed. All features and problems of Crystal Size distribution analysis, including why it has seemingly produced reasonable results, can be explained by this inherited correlation with modifications from Crystal mass and shape.
Yue-biao Zhang - One of the best experts on this subject based on the ideXlab platform.
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Diverse Crystal Size effects in covalent organic frameworks.
Nature communications, 2020Co-Authors: Lei Wei, Lin Liang, Shawn X. Yin, Jing Niu, Huadong Xue, Xiaoge Wang, Junliang Sun, Yue-biao ZhangAbstract:Crystal Size effect is of vital importance in materials science by exerting significant influence on various properties of materials and furthermore their functions. Crystal Size effect of covalent organic frameworks (COFs) has never been reported because their controllable synthesis is difficult, despite their promising properties have been exhibited in many aspects. Here, we report the diverse Crystal Size effects of two representative COFs based on the successful realization of Crystal-Size-controlled synthesis. For LZU-111 with rigid spiral channels, Size effect reflects in pore surface area by influencing the pore integrity, while for flexible COF-300 with straight channels, Crystal Size controls structural flexibility by altering the number of repeating units, which eventually changes sorption selectivity. With the understanding and insight of the structure-property correlation not only at microscale but also at mesoscale for COFs, this research will push the COF field step forward to a significant advancement in practical applications. Crystal Size effects are of vital importance to understand various properties and functions of a material but have not been reported for Covalent Organic Frameworks (COFs). Here, the authors report a Crystal-Size-controlled synthesis of two COFs and look into different Crystal Size effects.