in this study, different contents of nano-silica, 2 wt.%, 4 wt.% and 6 wt.%, have been added to bitumen tomodify the physical, mechanical and rheological properties of warm mix asphalt (wma). wma iscontaining 2 wt.% of sasobit (mixture of long-chain hydrocarbons). various quality control tests have beencarried out to characterize the modified bitumen and wma. the rheological investigations show...

Russian ( Acipenser gueldenstaedtii), Persian ( A. persicus) and Siberian ( A. baerii) sturgeons are closely related 'Ponto-Caspian' species. Investigation of their population structure is an important problem, the solution of which determines measures for conservation of these species. According to previous studies, 'baerii-like' mitotypes were found in the Caspian Sea among 35% of Russian stu...

BACKGROUND AND OBJECTIVES The US Environmental Protection Agency has suggested faecal enterococci as the primary bacterial indicators. Of more importance is their direct correlation with swimmer-associated gastroenteritis in recreation water quality monitoring. In contrast to other seawater bodies with 3.5% salinity, the recreational waters in the southern coast of the Caspian Sea possess its o...

this study was carried out to investigate the occurrence of potentially pathogenic species of vibrio in sea water and estuarine environments of the caspian sea in the golestan province of iran. a total of 127 water samples from coastal waters as well as from river and estuaries were collected and analyzed by culture, during april and september 2001. following prompt centrifugation, the resuspen...

In fiber concretes, microcracks in the boundary area between the cement paste and the surface of aggregates or fibers are higher. Natural and artificial pozzolans can be used for reinforcing this area. In this research, the combination of glass fiber, zeolite, and nano silica particles were used in lightweight self-compacting concrete containing scoria. Fiber volume fractions between 0% to 1.5%...

Many parameters are influenced by the diffusion of chloride on concrete in marine environments and these can affect concrete quality. In this study, the effect of water to cement ratio of 0.35, 0.40 and 0.45 on corrosion resistance and compressive strength of reinforced concrete was evaluated. Moreover, different percentages of micro silica (SiO2) including 5, 7.5 and 10% were utilized, in orde...

demonstration of the geomorphological factors in setting the legal regime of the caspian seaintroduction:the caspian sea is the largest water basin which enclosed by land within eurasia continent. the caspian sea is unique in many reasons: the large deposits of oil and gas, valuable fishery resources; including 90% of the world’s stock of sturgeon, important transportation routes; connecting th...