Oil change interval evaluation of civilian cars in urban traffic condition

In this study, it is tried to establish a theoretical model based on oil oxidation stability to evaluate the motor oil life. Five civilian cars and five motor oils were taken to eight road tests. The road tests contained two experiments taken in two test cars with the same car model, synthetic motor oil and test time, and three experiments taken in one test car with the same mineral oil to study the reliability and repeatability of the proposed method. The change characteristics of oxidation onset temperature, total acid number, and kinematic viscosity of test oils were analyzed. A theoretical model was established with the oxidation onset temperature and column chromatography method. The results showed the established theoretical model has the potential to quantitatively determine the remaining service time and operation mileage of the test oils with high accuracy and reliability. The test synthetic oils are able to operate approximately 11,000–13,000 km in 534–686 days in the typical urban traffic condition of China. The test mineral oils are capable of operating approximately 8200 km with 40 km/day or capable of operating 5723 km in 410 days. The proposed approach can provide some reference for end-users to drain their motor oil reasonably.

Preparation and Performance of Zr(Ca)-Al-O-N Composites by Reaction Sintering of Al-ZrO2(Ca) in N2 Atmosphere

Zr(Ca)-Al-O-N composites were prepared with ZrO2(Ca) (i.e Ca-PSZ, d50 < 10 μm) and Al powder (d50 =7.5 μm, 29 μm, and 62 μm) as raw materials by in situ reaction sintering in N2 atmosphere at 1600 °C. Phase constiturion of the composites was affirmed by XRD and SEM-EDS, and effect of grain size and content of Al powder on sintering performance of the composites was investigated, and oxidation characteristic of the composites were analysed by measure increasing weight of oxidation. The results showed that major phases of the composites composed of (t+c)-ZrO2, ZrN, ZrAl3O3N and CaAl12O19, and Al powder of 5 wt% - 7 wt% d50 =7.5 μm and 3 wt% - 5 wt% d50 =29 μm were suitable for preparation of the composites and bendiing strength of its samples sintered at 1600 °C had 60-90MPa. In atmosphere, oxidation onset temperature of Zr(Ca)-Al-O-N composites were approximately 550 °C, and the end temperature of its oxidening were approximately 950 °C. Treating with antioxidation is a key for application of Zr(Ca)-Al-O-N composites.

Thermooxidative stability of polymethyl methacrylate containing nanoparticles of silica/titania and silica/zirconia

The influence of silica/titania and silica/zirconia nanoparticles on thermooxidative degradation of PMMA was studied by non-isothermal thermogravimetry. Kinetic parameters describing the length of the oxidation induction periods were obtained from the treatment of the dependence of oxidation onset temperature on heating rate. Using these parameters, the protection factors of nanoparticles have been calculated. It was found that SiO2/TiO2 nanoparticles increase the thermooxidation stability of PMMA where the stabilizing effect, expressed as the protection factor, depends on temperature only slightly. The stabilizing effect of SiO2/ZrO2 is much stronger than that of SiO2/TiO2 and decreases with increasing temperature.

Synthesis and Catalytic Activity Studies of V/K/Ca and V/Ks/Ce Based Catalysts for Diesel Soot Oxidation

The catalysts based on V/K/Ca and V/Ks/Ce systems for diesel soot catalytic oxidation were synthesized onto the porous alumina substrates. Both catalyst systems showed a good catalytic oxidation activity. The V/K/Ca system exhibited the lowest oxidation onset temperature (OOT) of about 359oC with a composition of V/K/Ca =1:1:0.1 where the V and Ca and/or K elements could form a kind of amorphous phase that determined the catalytic activity. The V/Ks/Ce system displayed the lowest OOT of about 350oC with a composition of V/Ks/Ce = 1:2:0.1 where the K2SO4 and K5V2O3(SO4)4 phases could contribute most to the catalytic activity.