-Smectites synthesized from experiments at 5.5 GPa and 1500~ are of high quality, crystals are large at >10 p~m, and the 2:1 layers may have a homogeneous charge distribution. Smectite was exchanged with various cations (Na + , Li +, K +, Ca 2+, and Mg z+) and the hydration behavior of each sample was observed by an in situ powder X-ray diffraction method under precisely controlled relative hum...

In Part I macroscopic field equations of mass, linear and angular momentum, energy, and the quasistatic form of Maxwell’s equations for a multiphase, multicomponent medium were derived. Here we exploit the entropy inequality to obtain restrictions on constitutive relations at the macroscale for a 2-phase, multiple-constituent, polarizable mixture of fluids and solids. Specific emphasis is place...

-A high-charge smectite from Arizona [cation-exchange capacity (CEC) = 120 meq/100 g] and a low-charge smectite from Wyoming (CEC = 90 meq/100 g) were used to prepare homoionic tetramethylammonium (TMA)-clay complexes. The adsorption of benzene, toluene, and o-xylene as vapors by the dry TMA-clays and as solutes from water by the wet TMA-clays was studied. The adsorption of the organic vapors b...

-Chemical analysis by X-ray fluorescence (XRF) and calculated structural formulae of clay-size fractions of smectites from Cretaceous bentonites and illitic clays from Cretaceous, Devonian, and Ordovician bentonites and Jurassic and Permian sandstones indicate the nature and extent of various types of ionic substitution. The determination of tetrahedral (A1, Si) and octahedral (A1, Mg, Fe) comp...

347 Soil Sci. Soc. Am. J. 72:347-354 doi:10.2136/sssaj2007.0081 Received 22 Feb. 2007. *Corresponding author ([email protected]). © Soil Science Society of America 677 S. Segoe Rd. Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any informatio...

Introduction: Visible and near-IR (VNIR) spectral data for the martian surface obtained from orbit by the MRO-CRISM and OMEGA instruments are interpreted as having spectral signatures of H 2 O/OH-bearing phases, including smectites and other phyl-losilicates, sulfates, and high-SiO 2 phases [e.g., 1-4]. Interpretations of martian spectral signatures are based on and constrained by spectra that ...