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Rongwen Xi - One of the best experts on this subject based on the ideXlab platform.
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author correction transient scute activation via a self stimulatory loop directs enteroendocrine Cell Pair specification from self renewing intestinal stem Cells
Nature Cell Biology, 2018Co-Authors: Jun Chen, Huanwei Huang, Rongwen Xi, Pin Huang, Renjie Jiao, Zhongsheng Yu, Na Xu, Chenhui WangAbstract:In the version of this Article originally published, the author had misnumbered the reference citations in the Methods, using numbers 1–14 instead of 46–59. These errors have now been corrected in all online versions of the Article.
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transient scute activation via a self stimulatory loop directs enteroendocrine Cell Pair specification from self renewing intestinal stem Cells
Nature Cell Biology, 2018Co-Authors: Jun Chen, Huanwei Huang, Rongwen Xi, Pin Huang, Renjie Jiao, Zhongsheng Yu, Na Xu, Chenhui WangAbstract:The process through which multiple types of Cell-lineage-restricted progenitor Cells are specified from multipotent stem Cells is unclear. Here we show that, in intestinal stem Cell lineages in adult Drosophila, in which the Delta-Notch-signalling-guided progenitor Cell differentiation into enterocytes is the default mode, the specification of enteroendocrine Cells (EEs) is initiated by transient Scute activation in a process driven by transcriptional self-stimulation combined with a negative feedback regulation between Scute and Notch targets. Scute activation induces asymmetric intestinal stem Cell divisions that generate EE progenitor Cells. The mitosis-inducing and fate-inducing activities of Scute guide each EE progenitor Cell to divide exactly once prior to its terminal differentiation, yielding a Pair of EEs. The transient expression of a fate inducer therefore specifies both type and numbers of committed progenitor Cells originating from stem Cells, which could represent a general mechanism used for diversifying committed progenitor Cells from multipotent stem Cells.
Namjo Jeong - One of the best experts on this subject based on the ideXlab platform.
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assessing the behavior of the feed water constituents of a pilot scale 1000 Cell Pair reverse electrodialysis with seawater and municipal wastewater effluent
Water Research, 2019Co-Authors: Kyosik Hwang, Haejun Jeong, Seungcheol Yang, Jiyeon Choi, Namjo JeongAbstract:Abstract Reverse electrodialysis (RED) has vast potential as a clean, nonpolluting, and sustainable renewable energy source; however, pilot-scale RED studies employing real waters remain rare. This study reports the largest RED (1000 Cell Pairs, 250 m2) with municipal wastewater effluent (1.3–5.7 mS/cm) and seawater (52.9–53.8 mS/cm) as feed solutions. The RED stack was operated at a velocity of 1.5 cm/s and the pilot plant produced 95.8 W of power (0.38 W/m2 total membrane or 0.76 W/m2Cell Pair). During operation of the RED, the inlet design of the stack, comprising thin spacers, and the water dissociation reaction at the cathode were revealed as vulnerabilities of the stack. Specifically, pressure drops at the fluid inlet parts had the most detrimental effects on power output due to clogged spacers around the inlet parts. In addition, precipitates resulting in inorganic fouling were inevitable during the water dissociation reaction due to significant potential generated by the stack in the cathode chamber. Na+ and Cl− accounted for the majority of ions transferred from seawater to wastewater effluent through ion exchange membranes (IEMs). Moreover, some divalent cations in seawater, Mg2+ and Ca2+, were also transferred to the wastewater effluent. Some organics with relatively low molecular weights in the wastewater effluent passed through the IEMs, and their hydrophobic properties elevated the specific UV absorbance (SUVA) level in the seawater.
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assessing the behavior of the feed water constituents of a pilot scale 1000 Cell Pair reverse electrodialysis with seawater and municipal wastewater effluent
Water Research, 2019Co-Authors: Kyosik Hwang, Haejun Jeong, Seungcheol Yang, Jiyeon Choi, Namjo JeongAbstract:Abstract Reverse electrodialysis (RED) has vast potential as a clean, nonpolluting, and sustainable renewable energy source; however, pilot-scale RED studies employing real waters remain rare. This study reports the largest RED (1000 Cell Pairs, 250 m2) with municipal wastewater effluent (1.3–5.7 mS/cm) and seawater (52.9–53.8 mS/cm) as feed solutions. The RED stack was operated at a velocity of 1.5 cm/s and the pilot plant produced 95.8 W of power (0.38 W/m2 total membrane or 0.76 W/m2Cell Pair). During operation of the RED, the inlet design of the stack, comprising thin spacers, and the water dissociation reaction at the cathode were revealed as vulnerabilities of the stack. Specifically, pressure drops at the fluid inlet parts had the most detrimental effects on power output due to clogged spacers around the inlet parts. In addition, precipitates resulting in inorganic fouling were inevitable during the water dissociation reaction due to significant potential generated by the stack in the cathode chamber. Na+ and Cl− accounted for the majority of ions transferred from seawater to wastewater effluent through ion exchange membranes (IEMs). Moreover, some divalent cations in seawater, Mg2+ and Ca2+, were also transferred to the wastewater effluent. Some organics with relatively low molecular weights in the wastewater effluent passed through the IEMs, and their hydrophobic properties elevated the specific UV absorbance (SUVA) level in the seawater.
Kyosik Hwang - One of the best experts on this subject based on the ideXlab platform.
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assessing the behavior of the feed water constituents of a pilot scale 1000 Cell Pair reverse electrodialysis with seawater and municipal wastewater effluent
Water Research, 2019Co-Authors: Kyosik Hwang, Haejun Jeong, Seungcheol Yang, Jiyeon Choi, Namjo JeongAbstract:Abstract Reverse electrodialysis (RED) has vast potential as a clean, nonpolluting, and sustainable renewable energy source; however, pilot-scale RED studies employing real waters remain rare. This study reports the largest RED (1000 Cell Pairs, 250 m2) with municipal wastewater effluent (1.3–5.7 mS/cm) and seawater (52.9–53.8 mS/cm) as feed solutions. The RED stack was operated at a velocity of 1.5 cm/s and the pilot plant produced 95.8 W of power (0.38 W/m2 total membrane or 0.76 W/m2Cell Pair). During operation of the RED, the inlet design of the stack, comprising thin spacers, and the water dissociation reaction at the cathode were revealed as vulnerabilities of the stack. Specifically, pressure drops at the fluid inlet parts had the most detrimental effects on power output due to clogged spacers around the inlet parts. In addition, precipitates resulting in inorganic fouling were inevitable during the water dissociation reaction due to significant potential generated by the stack in the cathode chamber. Na+ and Cl− accounted for the majority of ions transferred from seawater to wastewater effluent through ion exchange membranes (IEMs). Moreover, some divalent cations in seawater, Mg2+ and Ca2+, were also transferred to the wastewater effluent. Some organics with relatively low molecular weights in the wastewater effluent passed through the IEMs, and their hydrophobic properties elevated the specific UV absorbance (SUVA) level in the seawater.
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assessing the behavior of the feed water constituents of a pilot scale 1000 Cell Pair reverse electrodialysis with seawater and municipal wastewater effluent
Water Research, 2019Co-Authors: Kyosik Hwang, Haejun Jeong, Seungcheol Yang, Jiyeon Choi, Namjo JeongAbstract:Abstract Reverse electrodialysis (RED) has vast potential as a clean, nonpolluting, and sustainable renewable energy source; however, pilot-scale RED studies employing real waters remain rare. This study reports the largest RED (1000 Cell Pairs, 250 m2) with municipal wastewater effluent (1.3–5.7 mS/cm) and seawater (52.9–53.8 mS/cm) as feed solutions. The RED stack was operated at a velocity of 1.5 cm/s and the pilot plant produced 95.8 W of power (0.38 W/m2 total membrane or 0.76 W/m2Cell Pair). During operation of the RED, the inlet design of the stack, comprising thin spacers, and the water dissociation reaction at the cathode were revealed as vulnerabilities of the stack. Specifically, pressure drops at the fluid inlet parts had the most detrimental effects on power output due to clogged spacers around the inlet parts. In addition, precipitates resulting in inorganic fouling were inevitable during the water dissociation reaction due to significant potential generated by the stack in the cathode chamber. Na+ and Cl− accounted for the majority of ions transferred from seawater to wastewater effluent through ion exchange membranes (IEMs). Moreover, some divalent cations in seawater, Mg2+ and Ca2+, were also transferred to the wastewater effluent. Some organics with relatively low molecular weights in the wastewater effluent passed through the IEMs, and their hydrophobic properties elevated the specific UV absorbance (SUVA) level in the seawater.
Yoshinobu Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Electric Power Generation with Reverse Electrodialysis
Journal of Membrane Science and Research, 2017Co-Authors: Yoshinobu TanakaAbstract:The computer simulation program of a practical scale reverse electrodialysis process has been developed based on the program for saline water electrodialysis. The program is applied to compute the performance of an industrial-scale reverse electrodialysis stack (effective membrane area S = 1 m × 1 m = 1 m2, Cell Pair number N = 300 Pairs). The stack operatingconditions are optimized. Seawater and brackish water are supplied to compute the overall membrane Pair characteristics, ion and solution flux across a membrane Pair, ion transport efficiency, generation efficiency, electric current leakage, stack electric resistance, stack voltage, external current, electric power, power density, pressure drop, limiting current density, and etc. When seawater (35000 ppm) and brackish water (1000 ppm) are used, the maximum power density is 0.85 W/m2 (15 °C), 1.10 W/m2 (25 °C) and 1.35 W/m2 (35 °C). Membrane electric resistance is less than brackish water electric resistance. Electric current leakage increases the electric power generation of the RED unit. Limiting current density is very large, so the unit is operated stably. By arranging 12 stacks, a small-scale reverse electrdialysis plant (N= 12×300 = 3600 Pairs) is assembled. The plant is operated to compute the performance changing external electric resistance.
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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.
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mass transport and energy consumption in ion exchange membrane electrodialysis of seawater
Journal of Membrane Science, 2003Co-Authors: Yoshinobu TanakaAbstract:Abstract The theory of ionic transport processes in ion-exchange membrane electrodialysis system was developed. The fundamentals in this theory is expressed by the overall mass transport equation of ions and a solution across a membrane Pair. The equation includes overall transport number λ , overall diffusion coefficient μ , overall electro-osmotic coefficient φ and overall osmotic coefficient ρ . These parameters indicate the characteristics of an ion-exchange membrane Pair placed in an electrolyte solution containing more than two kinds of ions. These parameters were measured by the electrodialysis of seawater. Parameters λ , μ and φ were expressed by empirical functions of ρ . These functions facilitate the simulation of the electrodialytic process. Parameter ρ was found to have the relation to non-equilibrium parameter; filtration coefficient L p . The formulas were obtained in order to express various aspects such as the transport of ions and solutions across membranes, electrolyte concentration in both a desalting and concentrating Cell, desalting ratio of a desalted solution and current efficiency. Ionic constituents in a concentrated solution were also measured by the seawater electrodialysis. The relationship between current density and the equivalent ratio of ions in a concentrated solution was expressed by empirical formulas. Thereby, the concentration of Na + , K + , Mg 2+ , Ca 2+ , Cl − and SO 4 2− ions in a concentrated solution was estimated. The voltage applied to a Cell Pair is known to be related to electrical resistance and membrane potential. The electrical resistance of solutions in a Cell Pair was determined by the specific resistance measurement of electrolyte solutions. The direct current electrical resistance of membranes in a Cell Pair was measured by the seawater electrodialysis. The effect of concentration polarization on the voltage applied to a Cell Pair is seen in the direct current resistance of the membrane. Energy consumption during the process of seawater electrodialysis was evaluated using the function of the voltage applied to a Cell Pair. The energy consumption, the limiting current density and the saturation current density are discussed on the basis that the current density and solution velocity (electrolyte concentration) in desalting Cells are distributed in an electrodialyzer.
Desmond F Lawler - One of the best experts on this subject based on the ideXlab platform.
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treatment of model inland brackish groundwater reverse osmosis concentrate with electrodialysis part ii sensitivity to voltage application and membranes
Desalination, 2014Co-Authors: Shane W Walker, Desmond F LawlerAbstract:Abstract The objective of this research was to investigate the sensitivity of electrodialysis performance to variations in voltage application and membranes when treating brackish water reverse osmosis concentrate waste. Synthetic BWRO concentrates from Arizona and Texas of 7890–14,800 mg/L total dissolved solids were prepared with poly-phosphonate antiscalants. Experimentation was performed using a laboratory-scale electrodialyzer with two sets of membranes (AMV-CMV and PCSA-PCSK) with a nominal transfer area of 64 cm 2 per membrane. Flow, pressure, conductivity, temperature, and pH were measured continuously, and periodic samples were analyzed for specific anion and cation concentrations. The BWRO concentrates were successfully treated with stack voltage applications of 0.5–1.5 V/Cell-Pair for salinity removal ratios up to 99% with current density less than 500 A/m 2 . This paper highlights that (1) the specific energy consumption was proportional to the applied voltage and equivalent concentration separated ( i.e. , approximately 0.03 kW h/m 3 per Volt/Cell-Pair applied per meq/L separated); (2) lower voltage applications decreased the relative separation rate of sulfate compared to chloride; and (3) water transport by electro-osmosis was independent of voltage application or resulting current densities, while it is affected by the ion exchange membranes.
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treatment of model inland brackish groundwater reverse osmosis concentrate with electrodialysis part i sensitivity to superficial velocity
Desalination, 2014Co-Authors: Shane W Walker, Desmond F LawlerAbstract:Abstract The objective of this research was to investigate the sensitivity of electrodialysis performance to variations in hydraulic flow when treating brackish water reverse osmosis (BWRO) concentrate waste. A synthetic BWRO concentrate from Arizona of 7890 mg/L total dissolved solids was prepared with poly-phosphonate antiscalants, and desalinated with a laboratory-scale electrodialyzer with 10 Cell-Pairs and a transfer area of 64 cm 2 per membrane. Flow, pressure, conductivity, temperature, and pH were measured continuously, and periodic process samples were analyzed by ion chromatography and inductively coupled plasma-optical emission spectrometry for anion and cation concentrations, respectively. The BWRO concentrate was successfully treated with a stack voltage application of 1.0 V/Cell-Pair and current densities less than 280 A/m 2 for salinity removal ratios up to 99% (without precipitation). The superficial velocities were controlled in a range of 1.2 to 4.8 cm/s, which corresponded to Reynolds numbers of 10 to 40. This paper shows the polarization parameter (ranging from 2.0 to 3.6 A/m 2 per meq/L) as a function of Reynolds number and removal ratio, and, at maximum sensitivity, the polarization parameter was proportional to Reynolds number raised to the 0.132 power.