In this study, linearized transport pore model (LTPM) is applied for modeling nanofiltration (NF) membrane separation process. This modeling approach is based on the modified extended Nernst-Planck equation enhanced by Debye-Huckel theory to take into account the variations of activity coefficient especially at high salt concentrations. Rejection of single-salt (NaCl) electrolyte is inve...

the aim of this research is to simulate oil spill behavior in the persian gulf due to the wind andtidal currents. this is achieved by coding an oil spill mathematical model consisting of several major submodels including hydrodynamic model, oil slick dynamic model and oil weathering model. the base of all of them is eulerian approach and they are coupled together to simulate spill incident in t...

ion channels are naturally occurring pores through the proteins that regulate the passage of ions and thus maintain the concentration of ions inside and outside the cell. the ion channels control many physiological functions and they can show selectivity for a specific ion. ion channels are mostly observed in nerve cells and muscle cells. the influx of ions into cells can be regulated by a gate...

the present sought to draw a comparison between model predictive control performance and two other controllers named simple pi and selective pi in controlling large-scale natural gas transport networks. a nonlinear dynamic model of representative gas pipeline was derived from pipeline governing rules and simulated in simulink® environment of matlab®. control schemes were designed to provide a s...

In this study, the techno-economic analysis of lignocellulosic biomass conversion to electricity in a small scale power plant was conducted. The proposed process is based on the thermal pathway of electricity production from a carbon content feed. Woods, forest and agricultural residues were considered as the biomass feed, which are available extensively in Iran. Besides, the process benefits n...

Differential scanning calorimetry (DSC), temperature programmed desorption mass spectrometry (TPD-MS) and small angle neutron scattering (SANS) were used to investigate CO2 uptake by the Wyodak coal. Adsorption of carbon dioxide on Wyodak coal was studied by DSC. The exotherms evident at low temperatures are associated with the uptake of CO2 suggesting that carbon diox...

In a recent Opinion paper, Wegner (Journal of Experimental Botany 65, 381–392, 2014) adapts a concept developed for water flow in animal tissues to propose a model, which can explain the loading of water into the root xylem against a difference in water potential (Ψ) between the xylem parenchyma cell (more negative Ψ) and the xylem vessel (less negative Ψ). In this model, the transport of water...

We examine the trans-Pacific transport of mercury using a global chemical transport model. Using existing anthropogenic inventories, the model reproduces the observed Hg/CO ratio in Asian long-range transport events observed at a surface site in Okinawa, Japan and Mount Bachelor, Oregon, with an underestimate of 18-26% in the ratio. This is in contrast with previous studies that inferred a fact...

In a recent Opinion paper, Wegner (Journal of Experimental Botany 65, 381-392, 2014) adapts a concept developed for water flow in animal tissues to propose a model, which can explain the loading of water into the root xylem against a difference in water potential (Ψ) between the xylem parenchyma cell (more negative Ψ) and the xylem vessel (less negative Ψ). In this model, the transport of water...

flow and sediment transport processes are different and more complex in coarse-bed rivers than in sand-bed rivers. the main goal of the present study is to evaluate different modes of sediment transport using different hydrometric and hydraulic methods, and to address the major uncertainties. four river reaches were selected as representatives of coarse-bed rivers in the northwest of iran. a se...