in this paper, the present state of knowledge about axial mixing in gasliquid reactors is reviewed. a brief outline of the methods for measuring residence time distribution(rtd)of various phases in a multiphase reactor is presented. this is followed by a short description of differential and stage-wise models for characterizing back mixing from rtd measurments. backmixing characteristics of som...

A method for the determination of total bile acids in human feces that is suitable for routine application is described and discussed. Bile acids are extracted from freezedried feces with acetic acid and toluene, in the presence of the i?ternal standard 23-nordeoxycholic acid. After saponification of the extract, bile acids and the internal standard are methylated and converted by mild chromic ...

quantum chemical calculations, based on density functional theory (dft) method, were performed on calix[4]arene and polychlorinated dibenzo-p-dioxins (pcdds) in gas and liquid phases for comparison purposes. the simulation results show the 1,2,3,4, 6,7,8,9-octachlorodibenzo-p-dioxin (ocdd) is quite a reactive dioxin. this paper attempts to examine the possibility of dioxin adsorption by calix[n...

In this work we propose an effective viscosity criterion for the stabilization of annular gas-liquid and liquid-particle flows and an inertial mechanism which drives waves into slugs in slugging gas-liquid flows. Annular flow is stable when the fluid having the higher effective viscosity occupies the core region and the lower viscosity fluid is the annulus. The eddy viscosity criterion is shown...

A liquid piston concept is proposed to improve the efficiency of gas compression and expansion. Because a liquid can conform to an irregular chamber volume, the surface area to volume ratio in the gas chamber can be maximized using a liquid piston. This creates near-isothermal operation, which minimizes energy lost to heat generation. A liquid piston eliminates gas leakage and replaces sliding ...

Gas-condensate reservoirs contain hydrocarbon fluids with characteristics between oil and gas reservoirs and a high gas-liquid ratio. Due to the large gas-liquid ratio, wellhead choke calculations using the empirical equations such as Gilbert may contain considerable error. In this study, using drill stem test (DST) data of a gas-condensate reservoir, coefficients of Gilbert equation was modifi...

4-Fluoropyrazole systems may be prepared by a single, sequential telescoped two-step continuous gas/liquid-liquid/liquid flow process from diketone, fluorine gas and hydrazine starting materials.

polycyclic aromatic hydrocarbons (pahs) which are toxic pollutants are released by various sources of urban combustion. ahvaz in iran with around a million population and the industrial and oil centers, has encountered air quality problems. samples of dibenzo (a,h) antheracen were collected from six stations in ahvaz particle and gas phase in summer 2010. dibenzo(a,h) antheracen were collected ...

In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two-phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, pre...