Friction and wear performances of magnesium alloy against steel under lubrication of rapeseed oil with S-containing additive

A S-containing additive, sulfuration modified rapeseed oil （named as SRO）, was prepared by chemical modification of rapeseed oil with sulfur compounds. The results indicate that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by formulating SRO into rapeseed oil lubricant. The friction coefficients and the wear volumes of magnesium alloy decrease with increasing contents of SRO. The surface lubricated with SRO-doped rapeseed oil was characterized by less wear as compared with that lubricated with neat rapeseed oil. The enhanced anti-wear and friction-reducing abilities of rapeseed oil by SRO in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of SRO and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.

An efficient method to extract DNA from refined rapeseed oil

Genetically modified oilseeds were used as processing raw material for edible oils. The protection of consumer rights to information as well as the genetically modified orgamisms （GMO） labe-ling polily required analytical methods to determine whether the oils contained genetically modified ingre-dient or not. Polymerase chain reaction （PCR） - based method was used commonly to determine the presence of GMOs. Adulteration attracted peoples concern also. Thus it was crucial that enough DNA ex-tracts can be obtained successfully from oil samples. For the purpose, three DNA extraction methods （modified emulsification method, the kits Wizard Magnetic DNA purification system for food and Nucleospin Food） ,were applied to 3 different grades of rapeseed oil samples. Those methods were compared by the amplification of Brassica napus reference gene CruA using real - time PCR. The results demonstra-ted that both the modified emulsification and the Nucleospin methods were able to extract enough DNA from refined oils. The modified emulsification method was superior to the kit of Nucleospin food due to smaller volume of required sample.

Evaluation of gas condensate reservoir behavior using velocity dependent relative permeability during the numerical well test analysis

Gas condensate is one of the most different fluids in reservoir simulation due to retrograde condensation in case of pressure reduction.In this kind of fluids,two phenomena named negative inertia and positive coupling,become significant in the high velocity zone around the wellbore.In this study,a modified black oil simulator is developed that take into account the velocity dependent relative permeability.Against the industrial simulator that assumes linear variation of transmissibilities by pressure,modified black oil nonlinear equations are solved directly without linearization.The developed code is validated by ECLIPSE simulator.The behavior of two real gas condensate fluids,a lean and a rich one,are compared with each other.For each fluid,simulations of PVT experiments are carried out to calculate black oil property applying Coats approach for gas condensate fluids.For both fluids,the proposed models for gas condensate velocity dependent relative permeability show different influence of velocity on relative permeability in the same conditions.Moreover,it is observed that higher flow rate of gas production leads to more condensate production during constant rate well testing.