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Abstract: Separation of asphaltenes from three types of Iranian crude oils of different asphaltene contents, using asymmetric, ceramic monolith membranes with the pore sizes of 0.2μm and 50nm was investigated. The experiments were conducted in a batch filtration unit at a differential pressure of 200kPa and a temperature of 120°C. Two important operating parameters including flux of permeate and asphaltene rejection were monitored as a function of time. A decline in the flux of permeate and an increase in the asphaltene rejection occurred as a result of fouling the membrane. The flux of permeate did not exhibit a strong function of pore size and this phenomenon confirmed that fouling of the membrane was according to the formation of gel layer. [Copyright &y& Elsevier]

Abstract: We record and analyze small earthquakes around Tehran, Iran, using the permanent seismological network of the Institute of Geophysics of the University of Tehran and two temporary dense seismological networks installed for several weeks during 1999 and 2000. Regional seismicity is distributed throughout Central Alborz, extending from the Caspian Sea to the Iran Plain, with the highest level of activity east of Tehran related to the Mosha and to the Garmsar faults, which both dip northward and have had strong historical earthquakes. Our focal mechanisms, the first for these faults, confirm a left lateral strike slip motion. [Copyright &y& Elsevier]

The influence of manufacturing parameters such as compacting pressure, heat treatment and microstructure on the static and dynamic properties of Fe–1.75 Ni–1.5 Cu–0.5 Mo–0.6 C was investigated. Wear and fatigue tests were carried out on reciprocate wearing and tension compression mode, respectively. The results show that delamination wear mechanism of sintered steel is similar to that of conventional wrought or cast materials. But, in sintered material, open porosity acts as sites of generation and collection of wear debris or formation of subsurface cracks. Wear rate is decreased and fatigue strength is increased by heat treatment. [Copyright &y& Elsevier]