No abstract

No abstract

The electrical capacitance at 70 c/s to 300 kc/s of physically adsorbed water on o(-Fe203 is constant within the monolayer volume but rises abruptly at low frequencies with the onset of a second layer. This behaviour suggests that the first layer of physically adsorbed water is immobile, but that succeeding layers are mobile. Characteristic relaxation frequencies obtained from Cole-Cole arc plots increase smoothly from 10 c/s to 10 kc/s at B.E.T. coverages of three or higher. Three intermediate stages in the build-up of the adsorbed water film are suggested : an immobile layer of physically adsorbed water doubly hydrogen bonded to the underlying hydroxyl layer, a more loosely held second layer of water on the average singly hydrogen bonded, and finally ordered ice-like layers. Dielectric activation energies calculated from the temperature dependence of the characteristic frequency give further evidence for a structured adsorbate. At 2+ layers, the activation energy is 16 kcal/mol, a value near that characteristic of dipole rotation in bulk ice. With increased coverage, the activation energy increases toward 25 kcal/mol, suggestive of increased interaction between adsorbate dipoles.

This paper examines sediment transport, sedimentation and properties of suspended matter and sediments in the Raša River estuary, a small, rock‐bounded, microtidal, low‐wave‐energy karstic estuary in the north‐eastern Adriatic. The Raša River is characterized by large variation in water flow and variable load of mineral particles. More than 90% of this load is brought into the estuary as fine‐grained suspended matter, consisting of only 24–36% of carbonates, the rest being clays. Sedimentation occurs at the salt wedge, resulting in a prograding estuarine delta. Salt‐induced flocculation is the predominant process of sediment deposition. The Raša estuary is infilling with sediment, and classifies as a disequilibrium estuary. We propose a modification of Cooper's (1993) classification scheme to include river‐dominated, disequilibrium estuaries, with the Raša River as an example.

No abstract