in this study argillic horizons in calcareous soils of a semiarid region, with xeric and mesic soil moisture and temperature regimes, in the west of urmia lake were studied. thus, a toposequence in different physiographic positions including piedmont plains, plateau, hills and mountains was investigated. in each land type, three soil profiles were dug and described and their morphological prope...

Clay fractions in soils from a transect of the Mazama ash deposit (6600-yr-old) contained more than 80% amorphous material. Instrumental neutron activation analysis was used to compare the trace element composition of the soil clay with the unweathered volcanic glass. The clay fractions had only 10% as much Na as the volcanic glass. Conversely, the rare earth element concentrations were about t...

We investigated the mineralogy of basalt weathering rinds and fresh basaltic rocks using visible/near-infrared (VNIR) (λ=0.4– 2.5 μm) and thermal emission (λ=6–30 μm) spectroscopy to 1) constrain the effects of chemical weathering on rock spectra, and 2) further understand the context of infrared spectra ofMars,whichmay contain evidence for weathered rocks and particulates derived from them. VN...

different amounts of nanoclay were incorporated into the acrylic resin matrix at 0, 1, 3, and 5 wt.% loadings. the coatings were applied on low carbon steel plates. optical microscopy, sedimentation test, transmission electron microscopy, and x-ray diffraction were employed to investigate the dispersion of nanoclay in matrix. the corrosion resistance of coatings was evaluated by electrochemical...

In this study, nanocomposite coatings based on polyurethane cerium nitrate montmorillonite (MMT) were prepared, applied on carbon steel substrates, and investigated. The nanocomposite coatings were successfully prepared by the effective dispersing of nanoparticles in polyurethane resin by mechanical and sonication processes. The state of dispersion, dissolution, and incorporation were character...

This research compared the influence of (1) dissolution of iron oxides and (2) alteration of electrostatic interactions on the mobilization of colloids in a clayand iron oxidecoated sand obtained from an Atlantic Coastal Plain aquifer in which colloids have been found suspended only in anoxic groundwater. The sediment was flushed with solutions of varying ionic strength, pH, and reductant and s...

The micromorphology and elemental composition of celestobarite crystals in a duripan from central Australia are examined. These crystals are flabellate (fan-shaped), have a Ba/Sr ratio of 11.1, and are up to 50 p.m in size. The location of the celestobarite crystals within silicified roots and in close association with calcite and clay coatings indicates that these celestobarite crystals are au...

micromorphology is the branch of soil science that is concerned with the description, interpretation and, to an increasing extent, the measurement of components, features and fabrics in soils at microscopic level. the advantage of micromorphology is that, in micromorphological studies the soils are studied in their natural and undisturbed form and so, one can follow the processes that take plac...

Highly loaded polymer/clay nanocomposites with layered structures are emerging as robust fire retardant surface coatings. However, time-intensive sequential deposition processes, e.g. layer-by-layer strategies, hinders obtaining large coating thicknesses and complicates an implementation into existing technologies. Here, we demonstrate a single-step, water-borne approach to prepare thick, self-...