the thermodynamic functions such as enthalpy (h), gibbs free energy (g) and entropy (s) ofpyrazole was theoretically studied at 5 different temperatures 25, 30, 35, 40 and 45°c by usinggussian o3, software. first, the structural optimization of isolated pyrazole was done in the gas phaseby appling the density functional theory (b3lyp) level with 3-21g, 6-31g and 6-31+g(d) basissets. moreover, v...

in this study, gas evolution in a vertical electrochemical cell is investigated numerically with a modified two-fluid model. the mathematical model involves solution of separate transport equation for the gas and liquid phases with an allowance to inter-phase transfer of mass and momentum. the governing equations are discreted via the finite volume technique and then are solved by the simple al...

Fundamental understanding of the goaf gas distribution in a gassy coal mine is necessary for developing effective goaf gas drainage strategies in the longwall coal mine. The goaf gas was subjected to the surface and body forces that were classified depending upon whether they acted on the surface area or the volume of the gas element. Of these forces, the body forces were more predominant in di...

Heat transfer phenomena in batch fluidized bed dryer have been studied and analyzed using three phase model including solid phase, interstitial gas phase and bubble phase based on Rizzi model. New correlations of heat transfer coefficient to surrounding and convection heat transfer coefficient between solid and interstitial gas are being proposed. In addition, some modifications have been d...

This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum...

In the continuous gas lift operation, compressed gas is injected into the lower section of tubing through annulus. The produced liquid flow rate is a function of gas injection rate and injection depth. All the equations to determine depth of injection assumes constant density for gas based on an average temperature of surface and bottomhole that decreases the accuracy of gas lift design. Also g...

We examine the development of a transient spiral arm in a disk galaxy made up of both gas and stars. To this end we have performed numerical simulations in a shearing sheet (basically a rectangular patch of a disc) that contains gas in the form of clouds behaving like Brahic’s (1977) sticky particles, and stars that appear as a background continuum providing the perturbation forces. These are c...

In this paper we compare the accuracy of a range of advanced density models for gas identification from sensor array signals. Density estimation is applied in the construction of classifiers through the use of Bayes rule. Experiments on real sensors data proved the effectiveness of the approach with an excellent classification performance. We compare the classification accuracy of four density ...