جستجوی مقالات مرتبط با کلیدواژه « bulk density » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

Static Young’s Modulus is a measure of reservoir rock stiffness and is best determined by experimental studies on cores. However, the experimental procedures are demanding with considerable cost. On the other hand, a dynamic Young’s modulus can easily be estimated from readily available petrophysical data. The static young’s modulus can easily be obtained from the dynamic counterpart by empirical relationships. This research attempts to use AI techniques to predict Static Young’s modulus. Two thousand three hundred fifty data sets were collected from several wells in the Middle East with sandstone and limestone lithology and used to build an AI model. Each data set contains static Young’s Modulus as a function of the bulk density, shear wave arrival time, and compressional wave arrival time. An artificial neural network (ANN) model was developed to predict the static young’s modulus with high accuracy of R2 = 0.999 and AARE of 0.028%. The proposed model was validated with measured reservoir rock data and was compared with four different correlations. The results showed that the model provided the highest coefficient of determination (R2) and the lowest standard deviation.

In this work, the interaction between a polystearylmethacrylate (Mn = 8,900 g mol-1, Xn = 26, Ð = 1.1) and modified methylaluminoxane 12 (MMAO-12) co-catalyst is studied using different spectroscopic methods. The effect of this oxygen-donor additive was measured by the changes in the bulk density of the raw polyethylene, which resulted increased respect to those obtained in blank reactions. A decrease in the activity was also observed as a penalty for the improvement of the bulk density, enhancing the possibility of reducing fouling. The coordination of the carbonyl oxygen groups of polystearylmethacrylate to aluminum (III) centers is confirmed by 1H-NMR and FTIR studies, and by a simple semi-empirical computational calculation. A method for obtaining a tri-component co-catalyst mixture is described using the methyl-bridging capacity of trimethylaluminum and its Lewis acidity to get the polystearylmethacrylate and MMAO-12 linked together. This robust adduct introduces a hierarchy over the PE chain growing, leading to higher bulk densities for PE beads (0.43 g cm-3) concerning blank reactions (0.26 g cm-3).

In this work, phosphate bonded refractory was developed using magnesium potassium phosphate cement and its physical, mechanical and thermal properties were evaluated. Cement was prepared from caustic calcined magnesium oxide with addition of mono potassium phosphate. Characterisation of cement was done by XRD and SEM to examine the change in phase and morphology which occurs after hydration of magnesium potassium phosphate cement which is in the form of struvite phase. To evaluate the physical, mechanical and thermal properties, refractory samples were casted and subsequently dried and fired at temperatures range of 1300°C to 1500°C. Then the bulk density, apparent porosity and crushing strength were analysed. It was found that the properties of chemical bonded refractory are better than convectional calcium alumina cement bonded refractory.The refractory specimens sintered at 1400oC, were analyzed for thermal and mechanical properties. They exhibited better wear resistance at both room temperature and at high temperature (1000oC). Properties of calcium alumina bonded refractory were also studied and compared with those made from magnesium potassium phosphate bonding. It is observed that the developed refractories are better in terms of wear resistance and thermal expansion. This indicates that the developed magnesium potassium phosphate bonding can be a good approach for fabricating refractories where high temperature resistance and wear resistance are required.