the neat bitumen, an oil refining by-product, has its own inherent weakness under long-time loading at low and high temperatures. these performance limitations of neat bitumen have led researchers to modify its physical andmechanical properties. according to several studies, polymers can be used to modify the properties of bitumen. due to much lower production costs and aiming to reduce environ...

it has been known for years that microbial surface active agents have a wide range of applications not only in oil spill environment but also in many industries. their properties including: (i) changing surface active phenomena, such as lowering of surface and interfacial tensions, (ii) wetting and penetrating actions, (iii) spreading, (iv) hydrophylicity and hydrophobicity actions, (v) microbi...

the polymeric and non-polymeric petrochemical wastes are environmentally unfavorable materials. we have to found a way to reuse these wastes in a safe manner. in styrene-butadiene rubber (sbr) production plant two major wastes are produced one is a fine rubber powder and the other is recycled n-methyl pyrrolidone (nmp). in high-density polyethylene (hdpe) production plant also a low molecular w...

scattering of an incoming wave train by a discontinuity at the upper surface of the ocean over a uniform porous bottom of finite depth is considered here in the framework of linearized water wave theory. by employing residue calculus method, the reflection and transmission coefficient are obtained. these coefficients are computed numerically for different values of the porosity parameter g and ...

due to performance grade  )pg) zonation of different parts in iran and poor properties of 60/70 penetration grade bitumens for pavement applications, suitable  polymer modifed  bitumen was  produced.  to  fulfll  this  purpose, different pmbs samples were produced using 60/70 penetration grade bitumen and  various  percentages  of vb  (20  and  25%), with  different  percentages  of  sbs calpre...

in the 1970 s, regulations in some counries forced usersof heavy residue to limit pollutant emissions at industrial sites, also forced producers to up grade their heavy products for export and domestic use. for this reason iran as a producer, exporter and consumer has to develop mew upgrading processes.the most common processes for upgrading heavy oil are catalytic processes, but existence of h...

The vacuum residue fraction of petroleum, comprising material with a normal boiling point of over 524°C, is a complex mixture of components with a wide range of molecular weight and chemical structure. The emphasis in process development and design for conversion of the vacuum residue fraction has tended to focus on the chemistry of the feed and the cracked products, and to some extent the chem...