The Experts below are selected from a list of 462639 Experts worldwide ranked by ideXlab platform
Guillermo Reglero - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature and Density on the performance of micropacked columns in supercritical fluid chromatography
Journal of Chromatography A, 1994Co-Authors: Elena Ibáñez, Javier Tabera, Marta Herraiz, Guillermo RegleroAbstract:Abstract The effects on the efficiency of micropacked columns in supercritical fluid chromatography (SFC) of Density at fixed temperature and of temperature at fixed Density were investigated. The variation of the retention and resolution achievable for a given pair of solutes with the mobile Phase Density under different isothermal conditions was also studied. The linear velocity was varied using several flow restrictors of different lengths and inner diameters. The column type investigated was characterized by an inside diameter of
Ali J. Chamkha - One of the best experts on this subject based on the ideXlab platform.
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Hydromagnetic free convection of a particulate suspension from a permeable inclined plate with heat absorption for non-uniform particle-Phase Density
Heat and Mass Transfer, 2003Co-Authors: Hasan M. Ramadan, Ali J. ChamkhaAbstract:The problem of steady, laminar, free convection flow of a particulate suspension over an infinite, permeable, inclined, and isothermal flat plate in the presence of a transverse magnetic field and fluid heat absorption effects is studied numerically. The problem accounts for particulate viscous effects which are absent from most two-Phase models. An analytical solution is developed for the particle-Phase Density distribution and numerical solutions for the velocity and temperature profiles of both Phases are obtained by using an implicit and iterative finite-difference method. A parametric study illustrating the influence of the magnetic field, heat absorption effects and particle loading is conducted. The obtained results for velocity, temperature and skin-friction coefficients for both Phases as well as the Nusselt number are illustrated graphically to show the features of the solution.
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Two-Phase free convection flow over an infinite permeable inclined plate with non-uniform particle-Phase Density
International Journal of Engineering Science, 1999Co-Authors: Hasan M. Ramadan, Ali J. ChamkhaAbstract:Abstract Continuum equations governing steady, laminar, free convection flow of a particulate suspension over an infinite, permeable, inclined and isothermal flat plate are studied. The equations account for particulate viscous and diffusive effects which are absent from most two-Phase fluid-particle models. An analytical solution is developed for the particle-Phase Density distribution. However, the velocity and temperature distributions of both the fluid and particle Phases are solved numerically by an implicit finite-difference method. These distributions along with the skin-friction coefficients of both Phases and the Nusselt number are illustrated graphically for various parametric conditions.
Jinyue Yan - One of the best experts on this subject based on the ideXlab platform.
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Impacts of thermo-physical properties of gas and liquid Phases on design of absorber for CO2 capture using monoethanolamine
International Journal of Greenhouse Gas Control, 2016Co-Authors: Worrada Nookuea, Yuting Tan, Eva Thorin, Jinyue YanAbstract:Abstract Absorption of CO 2 with aqueous amines in post-combustion capture is characterized as a heat and mass transfer processes with chemical reaction, which is sensitively affected by the thermo-physical properties of fluids. In order to optimize the design of the absorber of CO 2 capture process, in this paper, the impacts of thermo-physical properties on the column design were investigated. Furthermore, the property impacts on the capital cost of the absorber unit were also identified and analyzed. Results show that the gas Phase Density has the most significant effect on the column diameter. Underestimation of the gas Phase Density of 10% may result in an increase of about 6% of the column diameter. For the packing height, the liquid Phase Density has the most significant effect. 10% underestimation of the liquid Phase Density may result in an increase of 8% of the packing height. Moreover, the effect from the liquid Phase viscosity is also significant. For the annual capital cost, the liquid Phase Density also shows the most significant effect. Underestimation of the liquid Phase Density of 10% leads to the cost overestimation of $1.4 million for the absorption column for a 400 MW coal-fired power plant. Therefore, the development of the flue gas Density model and liquid Phase Density and viscosity models of the aqueous amine solution with CO 2 loading should be prioritized.
G H Roshani - One of the best experts on this subject based on the ideXlab platform.
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A high performance gas–liquid two-Phase flow meter based on gamma-ray attenuation and scattering
Nuclear Science and Techniques, 2017Co-Authors: G H Roshani, E NazemiAbstract:The ability to precisely estimate the void fraction of multiPhase flow in a pipe is very important in the petroleum industry. In this paper, an approach based on our previous works is proposed for predicting the void fraction independent of flow regime and liquid Phase Density changes in gas–liquid two-Phase flows. Implemented technique is a combination of dual modality densitometry and multi-beam gamma-ray attenuation techniques. The detection system is comprised of a single energy fan beam, two transmission detectors, and one scattering detector. In this work, artificial neural network (ANN) was also implemented to predict the void fraction percentage independent of the flow regime and liquid Phase Density changes. Registered counts in three detectors and void fraction percentage were utilized as the inputs and output of ANN, respectively. By applying the proposed methodology, the void fraction was estimated with a mean relative error of less than just 1.2480%.
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identification of flow regime and estimation of volume fraction independent of liquid Phase Density in gas liquid two Phase flow
Progress in Nuclear Energy, 2017Co-Authors: G H Roshani, E Nazemi, M M RoshaniAbstract:Abstract Changes of fluid properties, especially Density, strongly affect the performance of radiation-based multiPhase flow meter and could cause error in volume fraction measuring. One solution in such situations is continuous recalibration of the system, which is a difficult and long time task. In this study, a new methodology is presented for identifying flow regime and estimating the void fraction in gas-liquid flows independent of liquid Phase Density changes. The approach is based on gamma-ray attenuation and scattering combined with artificial neural networks (ANNs). The detection system uses a fan beam geometry, comprised of one 137 Cs source and three NaI(Tl) detectors. Two of these three detectors were implemented to measure transmitted photons and the third one was used to measure scattered photons. Also, four ANNs were used in this study, the first one for identifying the flow regime independent of liquid Phase Density changes and the other three ANNs for predicting void fraction independent of liquid Phase Density changes. Using this methodology, three flow regimes of annular, stratified and bubbly were correctly distinguished in liquid Phase Density changes range of 0.735–0.980 g/cm 3 and void fraction was predicted with a mean relative error (MRE) of less than 4.3%.
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a radiation based hydrocarbon two Phase flow meter for estimating of Phase fraction independent of liquid Phase Density in stratified regime
Flow Measurement and Instrumentation, 2015Co-Authors: E Nazemi, G H Roshani, S A H Feghhi, Saeid Setayeshi, Gholipour R PeyvandiAbstract:Abstract The fluid properties strongly affect the performance of radiation-based multiPhase flow meter. By changing the fluid properties (especially Density), recalibration is necessary. In this study, a method was presented to eliminate the dependency of multiPhase flow meter on liquid Phase Density in stratified two Phase horizontal flows. At the first step the position of the scattering detector was optimized in order to achieve highest sensitivity. Several experiments in optimized position were done. Counts under the full energy peak of transmission detector and total counts of scattering detector were applied to the Radial Basis Function neural network and the void fraction percentage was considered as the neural network output. Using this method, the void fraction was predicted independent of the liquid Phase Density change in stratified regime of gas–liquid two-Phase flows with mean relative error percentage less than 1.2%.
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void fraction prediction in two Phase flows independent of the liquid Phase Density changes
Radiation Measurements, 2014Co-Authors: E Nazemi, S A H Feghhi, G H RoshaniAbstract:Abstract Gamma-ray densitometry is a frequently used non-invasive method to determine void fraction in two-Phase gas liquid pipe flows. Performance of flow meters using gamma-ray attenuation depends strongly on the fluid properties. Variations of the fluid properties such as Density in situations where temperature and pressure fluctuate would cause significant errors in determination of the void fraction in two-Phase flows. A conventional solution overcoming such an obstacle is periodical recalibration which is a difficult task. This paper presents a method based on dual modality densitometry using Artificial Neural Network (ANN), which offers the advantage of measuring the void fraction independent of the liquid Phase changes. An experimental setup was implemented to generate the required input data for training the network. ANNs were trained on the registered counts of the transmission and scattering detectors in different liquid Phase densities and void fractions. Void fractions were predicted by ANNs with mean relative error of less than 0.45% in Density variations range of 0.735 up to 0.98 gcm−3. Applying this method would improve the performance of two-Phase flow meters and eliminates the necessity of periodical recalibration.
Eric P. Wallis - One of the best experts on this subject based on the ideXlab platform.
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Molecular simulation of the vapor-liquid equilibrium of methanethiol + propane mixtures
Fluid Phase Equilibria, 1997Co-Authors: Rupal Agrawal, Eric P. WallisAbstract:We have used the Gibbs ensemble Monte Carlo (GEMC) method to calculate the vapor-liquid equilibrium properties for pure propane and methanethiol as well as their mixtures. We used two different potential-energy surfaces to describe the propane and methanethiol molecules. The results show that the simple site-site potential-energy surfaces work well for the pure components by optimizing the parameters to reproduce the liquid-Phase Density at the normal boiling point. For mixtures, the site-site potential-energy surface predicts the liquid-Phase densities fairly well, but is not accurate enough to give quantitative results for the vapor-Phase mole fraction for this system.