[1] To understand the aqueous history of Mars, it is critical to constrain the alteration mineralogy of the Martian surface. Previously published analyses of thermal infrared (l = 6–25 mm) remote sensing data of Mars suggest that dark regions have 15–20% clay minerals. However, near-infrared (l = 1–3 mm) spectral results generally do not identify widespread clay minerals. Thermal infrared detec...

Hiring and Firing Costs, Adverse Selection and Long-Term Unemployment * In this paper, we present a matching model with adverse selection that explains why flows into and out of unemployment are much lower in Europe compared to North America, while employment-to-employment flows are similar in the two continents. In the model, firms use discretion in terms of whom to fire and, thus, low quality...

This study investigates the removal of tungsten from simulated water using biopolymer coated particles (i.e. chitosan coated clay) and natural clay. The effects of initial tungsten concentration (from 20 to 500 ppm) and water pH (4, 5.5 and 6.4) on zeta potential and tungsten removal were studied for both chitosan coated clay and natural clay. It was found that the net surface charge of natural...

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to...

Deoxyribonucleic Acid (DNA) has been recently found to be an efficient renewable and environmentally-friendly flame retardant. In this work, for the first time, we have used waste DNA from fishing industry to modify clay structure in order to increase the clay interactions with epoxy resin and take benefit of its additional thermal property effect on thermo-physical properties of epoxy-clay nan...

Hybrids based on recycled high density polyethylene (RHDPE) and organic clay were made by melt compounding. The influence of blending method, compatibilizers, and clay content on clay intercalation and exfoliation, RHDPE crystallization behavior, and the mechanical properties of RHDPE/clay hybrids were investigated. Both maleated polyethylene (MAPE) and titanate could improve the compatibilizat...

A controlled greenhouse experiment was conducted to study the fraction, uptake and fixation of phosphorus (P) and potassium (K) in three soils with contrasting characteristics. The experiment was carried out in two phases, viz., sorghum-Sudangrass depletion and test crop experiment with maize with three levels of fertility status (depleted, original and fertilized with 40 mg kg-1 P and K) and t...

The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs) and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay-carbon nanotube-chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decrease...

The influence of clay preparation methods on the sorption and hydrolysis of carbaryl (1-naphthyl, N-methyl carbamate) by K+-saturated reference smectite SWy-2 was studied. Four methods were utilized: (1) The reference (or specimen) clay used as received was K+-saturated (hereafter referred to as whole clay). (2) High-speed centrifugation (3295g) of whole clay resulted in a pellet with three dis...