Clay mineral-containing nanocomposite hydrogels have been proven to have exceptional composition, properties, and applications, and consequently have attracted a significant amount of research effort over the past few years. The objective of this paper is to summarize and evaluate scientific advances in clay mineral-containing nanocomposite hydrogels in terms of their specific preparation, form...

Earth dam is a structure as homogeneous or non-homogeneous forms for raising water level or water supply. Earth dam consist of different parts that one of the main parts is clay core. Choosing an optimal non permeable core which causes reduction of seepage through dam body and also being stable is necessary. The objective of this research is to optimize the geometry of earth dam clay core such ...

The aim of this study was the preparation of polyethylene oxide (PEO)/clay nanocomposites using organoclay produced via micellar adsorption of cethyltrimethyl ammonium bromide (CTAB) and their characterisation by X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectra, and the investigation of certain mechanical properties of the composites. The results show that the basal dista...

A method of clay mineral sample preparation for electron microprobe analysis has been developed in which a film of clay plus 10-12 wt. % colloidal graphite is deposited on a porous ceramic disc using a specially designed suction device. Correction procedures are used to obtain quantitative elemental analyses representing the average chemical composition of the prepared sample. A statistical tec...

Bacteria are the most abundant and active organisms in marine sediments and are critical for nutrient cycling and as a food source to many benthic and pelagic organisms. Bacteria are found both as free-living cells and as particle-associated cells, which can make investigations of these communities difficult. We found that common procedures for extracting bacteria from sediments leave the bacte...

From 1995 to 1998, more than 90 percent of mid-range IPOs were charged underwriter fees, or spreads, of exactly seven percent, even though evidence suggests that economies of scale in the size of the offering should allow for lower fees. Chen and Ritter (2000) offer collusion as a possible explanation based on empirical analysis and observation. Alternatively, we investigate whether the spreads...

Clay content (fraction < 2 μm) is one of the most important soil properties. It controls soil hydraulic properties like wilting point, field capacity and saturated hydraulic conductivity, which in turn control the various fluxes of water in the unsaturated zone. In our study site, the Kairouan plain in central Tunisia, existing soil maps are neither exhaustive nor sufficiently precise for water...

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...

The clay and non-clay minerals have been identified by XRD analysis. The non-clay minerals include quartz, crystobalite, orthoclase, microcline, plagioclase, calcite, siderite and dolomite, and the clay minerals include kaolinite (52.39%), illite (36.39%) and illite-smectite mixed layer minerals (11.21%). Kaolinite is the most dominant component in the clay mineral assemblages. The clay mineral...

High density polyethylene (HDPE)/bamboo composites with different nanoclay and maleated polyethylene (MAPE) contents were fabricated by melt compounding. The compounding characteristics, clay dispersion, HDPE crystallization, and mechanical properties of the composites were studied. The equilibrium torque during compounding decreased with use of clay masterbatch and increased with the addition ...