A Study of the Cyclic Variations of the Enzyme and the Electrolyte Activity in Uterine and Oviducal Secretions during an Estrous Cycle of the Ewe

Uterine and oviducal fluids are necessary for capacitation of the spermatozoa and early embryonic development. The aim of the present study was to determine the effects of estrous cycle phases (follicular and luteal) on some biological parameters (enzymes, electrolytes and total proteins) in uterine and oviducal secretions of ewes. Oviducal and uterine fluids were collected, diluted and centrifuged. According to our results, concentrations of GPT, G6PDH, total proteins, K and Na were significantly (P

Micropolar Fluids Effects on the Dynamic Characteristics of Four-lobe Journal Bearing

Dynamic characteristics of a four-lobe journal bearing of micropolar fluids are presented. Lubricating oil containing additives and contaminants is modelled as micropolar fluid. The modified Reynolds equation is obtained using the micropolar lubrication theory and solving it by using finite difference technique. The dynamic characteristics in terms of stiffness, damping coefficients, the critical mass and whirl ratio are determined for various values of size of material characteristic length and the coupling number. The results show compared with Newtonian fluids, that micropolar fluid exhibits better stability.

Richtmyer-Meshkov Instability and Gas-Particle Interaction of Contoured Shock-Tube Flows: A Numerical Study

In this paper, computational fluid dynamics (CFD) is utilized to characterize a prototype biolistic delivery system, the biomedical device based on the contoured-shock-tube design (CST), with the aim at investigating shocks induced flow instabilities within the contoured shock tube. The shock/interface interactions, the growth of perturbation at an interface between two fluids of different density are interrogated. The key features of the gas dynamics and gas-particle interaction are discussed

Modeling of Catalyst Deactivation in Catalytic Wet Air Oxidation of Phenol in Fixed Bed Three-Phase Reactor

Modeling and simulation of fixed bed three-phase catalytic reactors are considered for wet air catalytic oxidation of phenol to perform a comparative numerical analysis between tricklebed and packed-bubble column reactors. The modeling involves material balances both for the catalyst particle as well as for different fluid phases. Catalyst deactivation is also considered in a transient reactor model to investigate the effects of various parameters including reactor temperature on catalyst deactivation. The simulation results indicated that packed-bubble columns were slightly superior in performance than trickle beds. It was also found that reaction temperature was the most effective parameter in catalyst deactivation.

A Study on the Effects of Thermodynamic Nonideality and Mass Transfer on Multi-phase Hydrodynamics Using CFD Methods

Considering non-ideal behavior of fluids and its effects on hydrodynamic and mass transfer in multiphase flow is very essential. Simulations were performed that takes into account the effects of mass transfer and mixture non-ideality on hydrodynamics reported by Irani et al. In this paper, by assuming the density of phases to be constant and Raullt-s law instead of using EOS and fugacity coefficient definition, respectively for both the liquid and gas phases, the importance of non-ideality effects on mass transfer and hydrodynamic behavior was studied. The results for a system of octane/propane (T=323 K, P =445 kpa) also indicated that the assumption of constant density in simulation had major role to diverse from experimental data. Furthermore, comparison between obtained results and the previous report indicated significant differences between experimental data and simulation results with more ideal assumptions.

Flow and Heat Transfer of a Nanofluid over a Shrinking Sheet

The problem of laminar fluid flow which results from the shrinking of a permeable surface in a nanofluid has been investigated numerically. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. A similarity solution is presented which depends on the mass suction parameter S, Prandtl number Pr, Lewis number Le, Brownian motion number Nb and thermophoresis number Nt. It was found that the reduced Nusselt number is decreasing function of each dimensionless number.