The Experts below are selected from a list of 33117 Experts worldwide ranked by ideXlab platform
J F Diaz - One of the best experts on this subject based on the ideXlab platform.
-
Nanofiltration modeling: a comparative study of the salt filtration performance of a charged ceramic membrane and an organic nanofilter using the Computer Simulation Program nanoflux
Separation and Purification Technology, 2003Co-Authors: Xavier Lefebvre, Joh Palmeri, Christia Guizard, Philippe Amblard, J F Diaz, Roger Sandeaux, B Maleyre, P. David, Jacqueline Sandeaux, B. LamazeAbstract:Abstract The results of a detailed experimental and theoretical study of the rejection of single salts and multi-electrolyte mixtures by a loose ceramic TiO 2 (SCT Membralox®) membrane at the borderline between ultra- and nanofiltration (NF) are compared with similar results obtained using a tighter organic nanofilter (NF200). Theoretical ion rejection predictions for multi-electrolyte solutions are obtained by solving numerically the hindered transport extended Nernst–Planck (ENP) ion flux equations using our Computer Simulation Program, nanoflux , which incorporates electrostatic, steric, and hydrodynamic interactions and a new choice for ion size (bare crystal, or Pauling, radius). We find that, depending on the operating conditions, the looser ceramic nanofilter does not necessarily perform less well than the tighter organic one. We also examine how well the rejection of multi-electrolyte mixtures can be predicted by hindered electro-transport theory (HETT), using a database of single salt results, over a wide range of relative salt mole proportions and pH. Finally, we propose a combined experimental and theoretical method for characterizing, simulating, and optimizing the performance of charged nanofilters using the Computer Program nanoflux .
-
modeling of multi electrolyte transport in charged ceramic and organic nanofilters using the Computer Simulation Program nanoflux
Desalination, 2002Co-Authors: Joh Palmeri, Jacqueline Sandeau, R Sandeau, Xavie Lefebvre, Christia Guizard, Philippe Amblard, P. David, J F DiazAbstract:Abstract We present a comparative study of the filtration performance of one ceramic and two organic nanofilters. The results of a detailed experimental and theoretical investigation of the rejection of single salts (NaCl, NaNO3, and CaCl2) and multi-electrolyte mixtures (NaCl/CaCl2/HCl and NaNO3/NaCl/CaCl2) by a loose ceramic TiO2 nanofilter (Membralox SCT) are compared with similar results obtained using two organic nanofilters (Desal 5 and NF200). We modelion transport in nanoscale pores using a hybrid Hindered Electro-Transport Theory (HETT) that accounts for the charge and size of ions. Theoretical ion rejections for multi-electrolyte mixtures are obtained by solving numerically the Hindered Transport extended Nernst-Planck ion flux Eqs. using a Computer Simulation Program, NanoFlux, that we have developed to simulate transport in the nanofiltration range. The ion rejection in binary and ternary mixtures is reasonably well predicted by the theory, over a wide range of pH and relative salt mole fraction, from the single salt results, using an appropriate weighting and interpolation scheme.
Joh Palmeri - One of the best experts on this subject based on the ideXlab platform.
-
Nanofiltration modeling: a comparative study of the salt filtration performance of a charged ceramic membrane and an organic nanofilter using the Computer Simulation Program nanoflux
Separation and Purification Technology, 2003Co-Authors: Xavier Lefebvre, Joh Palmeri, Christia Guizard, Philippe Amblard, J F Diaz, Roger Sandeaux, B Maleyre, P. David, Jacqueline Sandeaux, B. LamazeAbstract:Abstract The results of a detailed experimental and theoretical study of the rejection of single salts and multi-electrolyte mixtures by a loose ceramic TiO 2 (SCT Membralox®) membrane at the borderline between ultra- and nanofiltration (NF) are compared with similar results obtained using a tighter organic nanofilter (NF200). Theoretical ion rejection predictions for multi-electrolyte solutions are obtained by solving numerically the hindered transport extended Nernst–Planck (ENP) ion flux equations using our Computer Simulation Program, nanoflux , which incorporates electrostatic, steric, and hydrodynamic interactions and a new choice for ion size (bare crystal, or Pauling, radius). We find that, depending on the operating conditions, the looser ceramic nanofilter does not necessarily perform less well than the tighter organic one. We also examine how well the rejection of multi-electrolyte mixtures can be predicted by hindered electro-transport theory (HETT), using a database of single salt results, over a wide range of relative salt mole proportions and pH. Finally, we propose a combined experimental and theoretical method for characterizing, simulating, and optimizing the performance of charged nanofilters using the Computer Program nanoflux .
-
modeling of multi electrolyte transport in charged ceramic and organic nanofilters using the Computer Simulation Program nanoflux
Desalination, 2002Co-Authors: Joh Palmeri, Jacqueline Sandeau, R Sandeau, Xavie Lefebvre, Christia Guizard, Philippe Amblard, P. David, J F DiazAbstract:Abstract We present a comparative study of the filtration performance of one ceramic and two organic nanofilters. The results of a detailed experimental and theoretical investigation of the rejection of single salts (NaCl, NaNO3, and CaCl2) and multi-electrolyte mixtures (NaCl/CaCl2/HCl and NaNO3/NaCl/CaCl2) by a loose ceramic TiO2 nanofilter (Membralox SCT) are compared with similar results obtained using two organic nanofilters (Desal 5 and NF200). We modelion transport in nanoscale pores using a hybrid Hindered Electro-Transport Theory (HETT) that accounts for the charge and size of ions. Theoretical ion rejections for multi-electrolyte mixtures are obtained by solving numerically the Hindered Transport extended Nernst-Planck ion flux Eqs. using a Computer Simulation Program, NanoFlux, that we have developed to simulate transport in the nanofiltration range. The ion rejection in binary and ternary mixtures is reasonably well predicted by the theory, over a wide range of pH and relative salt mole fraction, from the single salt results, using an appropriate weighting and interpolation scheme.
Yu-chu Yeh - One of the best experts on this subject based on the ideXlab platform.
-
Nurturing reflective teaching during critical-thinking instruction in a Computer Simulation Program
Computers & Education, 2004Co-Authors: Yu-chu YehAbstract:Nurturing reflective teaching and improving critical-thinking instruction are two important goals in teacher education, but these are only achievable when teachers-in-training are provided with opportunities for building professional knowledge and for exhibiting reflective teaching practices. A Computer Simulation Program (CS-TGCTS) was therefore developed here, and its effectiveness is explained in this study. From 149 preservice teachers participating in this study, a pretest-posttest control group design was defined by four student groups and two treatments. The central hypothesis was that increasing participants' self-awareness of teacher behaviors and enhancing mindful learning in professional knowledge would provoke reflective teaching and further bring about improvements in teacher behaviors. The findings support the hypothesis and suggest that the CS-TGCTS Simulation is an effective vehicle for improving preservice teachers' reflective teaching in critical-thinking instruction.
Yoshinobu Tanaka - One of the best experts on this subject based on the ideXlab platform.
-
Computer Simulation Program: Feed-and-Bleed Program
Ion Exchange Membranes, 2015Co-Authors: Yoshinobu TanakaAbstract:In a feed-and-bleed operation, a feeding solution is recycled between a circulation tank and an electrodialyzer continuously. The recycle rate is determined as desired from the targeted concentration changes of the desalted solution. An electrodialyzer and a circulation tank are the main units working in the feed-and-bleed process. The function of the electrodialyzer is computed based on the single-pass (continuous) Program ( Chapter 13 ), which is developed for the single-pass operation. The Computer Program of the feed-and-bleed operation consists of (1) the Program describing the function of the electrodialyzer and (2) the Program describing the function of the circulation tank. The function of the circulation tank is introduced from the mass balance in the tank. The performance of the process is computed by inputting the process specifications and operating conditions into the stand-alone Program and carried out trial-error-calculation.
-
Computer Simulation Program: Batch Program
Ion Exchange Membranes, 2015Co-Authors: Yoshinobu TanakaAbstract:The batch process is applicable for operating small- or middle-scale electrodialysis. An electrodialyzer and a circulation tank are the main units working in the batch process. The batch Program is divided into two steps expressing the function of the electrodialyzer (step 1) and that of the circulation tank (step 2). The 11 coefficients computed in step 1 are integrated into the spreadsheet with the equations developed in step 2. The computation in step 2 is carried out with the open/shut solution feeding operation with the use of common software (Excel) and ordinary hardware (Computer). The overall computations are not carried out with the standalone Program as developed in the single-pass and the feed-and-bleed processes. Saline water is desalinated to produce drinking water employing this batch Program.
-
Computer Simulation Program: Single-Pass (Continuous) Program
Ion Exchange Membranes, 2015Co-Authors: Yoshinobu TanakaAbstract:The single-pass (continuous) Program is the basis of the feed-and-bleed Program and the batch Program. This is because the single-pass Program describes the function of the electrodialyzer. This chapter describes the stand-alone single-pass Program established based on the principles of electrochemistry and electrodialysis experiments being supplied strong electrolyte solutions. Calculation is carried out in the spreadsheet with the use of common software (Excel) and ordinary hardware (Computer). The Program is integrated in Web sites. So, readers can operate the Program in the websites by inputting the source code, i.e., optional process specifications and operating conditions. The Program aims to function as a pilot plant operation. The single-pass Program is classified to (1) Constant current Program, (2) constant voltage Program, and (3) constant salt concentration Program. The process specifications and electrodialysis conditions are inputted into the Programs and the performance of the processes are computed with trial-and-error calculations.
-
Encyclopedia of Membrane Science and Technology - Mass Transport in Ion‐Exchange Membranes
Encyclopedia of Membrane Science and Technology, 2013Co-Authors: Yoshinobu TanakaAbstract:Irreversible thermodynamics is the fundamental principle that expresses the mass transport across ion-exchange membranes. The overall mass transport equation is developed with electrodialysis experiments and applied to discuss the performance of an electrodialyzsis process. The Computer Simulation Program is developed using fundamental principles of electrodialysis. Performance of saline water desalination is computed by inputting electrodialyzer specifications and operating conditions. Mechanism of concentration polarization is discussed based on the mass transport across a boundary layer formed on an ion-exchange membrane. Mechanism of the water dissociation reaction is discussed based on electric potential generated by ion-exchange groups in the membrane. Keywords: ion-exchange membrane electrodialysis; irreversible thermodynamics; mass transport; Computer Simulation Program; saline water desalination; concentration polarization; boundary layer; limiting current density; water dissociation; ion-exchange group
-
Development of a Computer Simulation Program of batch ion-exchange membrane electrodialysis for saline water desalination
Desalination, 2013Co-Authors: Yoshinobu TanakaAbstract:Abstract A Computer Simulation Program is developed to predict the desalinating performance of a constant voltage feed-and-bleed electrodialysis process, inputting membrane characteristics, electrodialyzer specifications and electrodialytic conditions. A salt solution is supplied to a one-stage or a two-stage process to produce drinking water. Energy consumption for ion transport and limiting cell voltage in both processes are equivalent. In order to operate the two-stage process effectively, the cell pair number in the first stage should be the same to that in the second stage. Current density in the two-stage process becomes larger than that in the one-stage process because salt concentration in the first stage in the two-stage process is increased. Thus, the cell pair number integrated in the two-stage process is reduced compared to that in the one-stage process for producing the same amount of drinking water. Water recovery of the two-stage process is larger than that in the one-stage process because the cell pair number (thus solution feed to concentrating cells in the two-stage process) is reduced compared to that in the one-stage process.
Christia Guizard - One of the best experts on this subject based on the ideXlab platform.
-
Nanofiltration modeling: a comparative study of the salt filtration performance of a charged ceramic membrane and an organic nanofilter using the Computer Simulation Program nanoflux
Separation and Purification Technology, 2003Co-Authors: Xavier Lefebvre, Joh Palmeri, Christia Guizard, Philippe Amblard, J F Diaz, Roger Sandeaux, B Maleyre, P. David, Jacqueline Sandeaux, B. LamazeAbstract:Abstract The results of a detailed experimental and theoretical study of the rejection of single salts and multi-electrolyte mixtures by a loose ceramic TiO 2 (SCT Membralox®) membrane at the borderline between ultra- and nanofiltration (NF) are compared with similar results obtained using a tighter organic nanofilter (NF200). Theoretical ion rejection predictions for multi-electrolyte solutions are obtained by solving numerically the hindered transport extended Nernst–Planck (ENP) ion flux equations using our Computer Simulation Program, nanoflux , which incorporates electrostatic, steric, and hydrodynamic interactions and a new choice for ion size (bare crystal, or Pauling, radius). We find that, depending on the operating conditions, the looser ceramic nanofilter does not necessarily perform less well than the tighter organic one. We also examine how well the rejection of multi-electrolyte mixtures can be predicted by hindered electro-transport theory (HETT), using a database of single salt results, over a wide range of relative salt mole proportions and pH. Finally, we propose a combined experimental and theoretical method for characterizing, simulating, and optimizing the performance of charged nanofilters using the Computer Program nanoflux .
-
modeling of multi electrolyte transport in charged ceramic and organic nanofilters using the Computer Simulation Program nanoflux
Desalination, 2002Co-Authors: Joh Palmeri, Jacqueline Sandeau, R Sandeau, Xavie Lefebvre, Christia Guizard, Philippe Amblard, P. David, J F DiazAbstract:Abstract We present a comparative study of the filtration performance of one ceramic and two organic nanofilters. The results of a detailed experimental and theoretical investigation of the rejection of single salts (NaCl, NaNO3, and CaCl2) and multi-electrolyte mixtures (NaCl/CaCl2/HCl and NaNO3/NaCl/CaCl2) by a loose ceramic TiO2 nanofilter (Membralox SCT) are compared with similar results obtained using two organic nanofilters (Desal 5 and NF200). We modelion transport in nanoscale pores using a hybrid Hindered Electro-Transport Theory (HETT) that accounts for the charge and size of ions. Theoretical ion rejections for multi-electrolyte mixtures are obtained by solving numerically the Hindered Transport extended Nernst-Planck ion flux Eqs. using a Computer Simulation Program, NanoFlux, that we have developed to simulate transport in the nanofiltration range. The ion rejection in binary and ternary mixtures is reasonably well predicted by the theory, over a wide range of pH and relative salt mole fraction, from the single salt results, using an appropriate weighting and interpolation scheme.