Advanced Materials Research Vols. 560-561

Abstract: In this study, the sorption of Cu(II) ions in aqueous solutions of Zeolite NaA by performing batch kinetic sorption experiments. The equilibrium kinetic data were analyzed using the pseudo-second-order kinetic model. A comparison was made of the linear least-squares method and nonlinear method of the widely used pseudo-second-order kinetic model for the sorption of Cu(II) ions of Zeolite . Four pseudo-second-order kinetic linear equations are discussed. Kinetic parameters obtained from the four kinetic linear equations using the linear method differed but they were the same when using the non-linear method. Kinetic parameters obtained from four kinetic linear equations using the linear method differed. Equation type 1 pseudo-second-order kinetic model very well represented the kinetic of the adsorption Cu(II) ions by Zeolite NaA. Equation type 4 exhibited the worst fit. Present investigation showed that the non-linear method may be a better way to determine the kinetic parameters.

Abstract: Flash point is one of the most important variables used to characterize fire and explosion hazard of liquids. This paper predicts the flash point of binary partially miscible aqueous mixtures by using the flash point prediction model of Liaw et al. handling non-ideal behavior through liquid phase activity coefficients evaluated with UNIFAC-type models, which do not need experimentally regressed binary parameters. Validation of this entirely predictive model is conclusive with the experimental data over the entire flammable composition range. Overall, the proposed method predicted the experimental data very well. Potential application for this approach concerns the classification of flammable liquid mixtures in the implementation of GHS.

Abstract: The natural convection of nanofluids in a two-dimensional enclosure is numerically simulated with Fluent software. The effect of copper particle concentration and Grashof number on heat transfer properties is investigated. The results indicate that the suspended copper nanoparticles substantially increase the heat transfer rate at any given Grashof number, and the heat transfer rate of the nanofluid increases remarkably with the mass fraction of nanoparticles. For a given initial Grashof number, as the mass fraction increases, the velocity components of nanofluid increase as a result of an increase in the energy transport through the fluid. In addition, the intensity of the streamline increase with the increases of the Grashof number, which indicate the heat transfer properties are enhanced. The heat transfer process is dominant with the heat exchange at low Gr, while the heat transfer process is dominant with the natural convection at high Gr.

Abstract: For a case of constant-rate liquid production from a single well centered in a horizontal, homogeneous-acting, isopachous, and infinite reservoir, based on fundamentals of fluid flow in porous media the bottom hole flowing pressure never stabilize. In the process of field well testing, however, pressure values measured by the pressure gauge which has a definite resolution value will not change after a period, so the bottom hole flowing pressure can be considered to be stabilized. According to this situation, through theoretical derivation, a stabilized time formula is firstly proposed, by which the time after which the bottom hole flowing pressure measured with a pressure gauge will be stabilized can be calculated, and the stabilized time for a given pressure gauge is in direct proportion to the liquid producing rate, but in inverse proportion to the resolution ratio of the pressure gauge. Applied the stabilized time formula, a new formula of detectable radius can be derived, by which the effect of resolution of the pressure gauge can be considered. Secondly, the time after which the value of the pressure gauge measured in the bottom hole of the observation well starts to change during interference testing is obtained, and the time is related to the fluid flow rate and the distance between the producing well and the observation well. The conclusion can be applied as a reference in the design process of working system during well testing.