a modification of peng-robinson equation is described wherein in the parameter b is expressed as a linear function of temperature. the modified equation is then applied to a series of light hydrocarbons and refrigerants, and predicted values for vapor pressure, saturated vapor volume, saturated liquid volume and the heat of evaporation are compared with the corresponding experimental data. cons...

where u is a vector-valued function representing the velocity of the fluid, and p is the pressure. Note that the pressure depends in a non local way on the velocity u. It can be seen as a Lagrange multiplier associated to the incompressible condition (2). The initial value problem of the above equation is endowed with the condition that u(0, ·) = u0 ∈ L (R). Leray [11] and Hopf [6] had already ...

Gas phase polymerization of propylene was carried out in a semi-batch minireactor using a commercially supported Ziegler–Natta (ZN) catalyst. The influence of variables including monomer partial pressure, external electron donor, reaction temperature and time on the particle morphology and size distribution was investigated. Generally, more uniform fragmentation and particle densities were obta...

The thermal flow reversal reactor (TFRR) and catalytic flow reversal reactor (CFRR) can utilize the ventilation air methane (VAM) from coal mines effectively. The initial cold feed flow mass distribution uniformity in the monolith oxidation bed, the critical part of both reactors, has a great influence on the stability of methane oxidation process and conversation rate. So the emphases are put ...

A CFD technique for predicting the performance of axisymmetric packed bed filters has been developed. The effect on the pressure drop of a non-uniform voidage distribution within the filter bed has been modelled. A radial voidage distribution was derived from a predictive model based on a modified Mueller equation. The pressure loss through the bed was calculated from the Ergun equation, using ...

arterial blood gas parameters were analyzed in forty-nine healthy persons (31 males, 18 females) to detemine reference values fo these parameters and their relation to the time from last food intake to arterial puncture (t). the mean ± standard deviation of arterial oxygen pressure, arterial carbon dioxide pressure and ph at core body temperature were 84.4±7.0 mmhg (male: 83.0±6.5, female: 86.7...

We have read with much interest the recent article by Firstenberg et al. (1), which provides new insights into the comprehension of noninvasive assessment of transmitral pressure drop. In their Figure 2, the investigators display a graph demonstrating how the inclusion of inertial term in the pressure calculation allows an estimation of pressure drop across the mitral valve closely related to t...

We show that regular structures governed by an equation of state (EOS) or density variation such that the density at the surface does not vanish together with pressure (also known as self-bound regular structures) can not exist in the state of hydrostatic equilibrium. The only configuration which could exist in this regard is governed by homogeneous density distribution. Other structures which ...

This work is a primary achievement in studying the CO2 and N2–oil systems. To predict gas-liquid relative permeability curves, a Shan-Chen type multicomponent multiphase lattice Boltzmann model for two-phase flow through 2D porous media is developed. Periodic and bounce back boundary conditions are applied to the model with the Guo scheme for the external body force (i.e.,...

The elasticity mixed boundary values problems dealing with half-space contact are generally well resolved. A large number of these solutions are obtained by using the integral transformation method and methods based the integral equations. However, the problems of finite layer thicknesses are less investigated, despite their practical interests. This study resolves a quasi-stationary problem of...