Carbon dioxide(CO_2) is greenhouse gas which originates primarily as a main combustion product of biogas and landfill gas. To separate this gas, an inside coated thin film composite(TFC) hollow fiber membrane was deve...Carbon dioxide(CO_2) is greenhouse gas which originates primarily as a main combustion product of biogas and landfill gas. To separate this gas, an inside coated thin film composite(TFC) hollow fiber membrane was developed by interfacial polymerization between 1,3–cyclohexanebis–methylamine(CHMA) and trimesoyl chloride(TMC). ATR-FTIR, SEM and AFM were used to characterize the active thin layer formed inside the PSf hollow fiber. The separation behavior of the CHMA-TMC/PSf membrane was scrutinized by studying various effects like feed gas pressure and temperature. Furthermore, the influence of CHMA concentration and TMC concentration on membrane morphology and performance were investigated. As a result, it was found that mutually the CHMA concentration and TMC concentration play key roles in determining membrane morphology and performance. Moreover, the CHMA-TMC/PSf composite membrane showed good CO_2/CH_4 separation performance. For CO_2/CH_4 mixture gas(30/70 by volume) test, the membrane(PD1 prepared by CHMA 1.0% and TMC 0.5%) showed a CO_2 permeance of 25 GPU and the best CO_2/CH_4 selectivity of 28 at stage cut of 0.1. The high CO_2/CH_4 separation performance of CHMA-TMC/PSf thin film composite membrane was mostly accredited to the thin film thickness and the properties of binary amino groups.展开更多
Social media users attracted the attention of scholars at home and abroad.This paper conducted a detailed literature review and prposed an analytical framework to define and conceptualize social media users on the ＂A...Social media users attracted the attention of scholars at home and abroad.This paper conducted a detailed literature review and prposed an analytical framework to define and conceptualize social media users on the ＂Actual Man＂ theory of Marxism.Furthermore, the paper generalizes three research levels, including the individual level,the gruop level and the materialism level.This study can improve understanding of the users＇ behavior in the social media virtue world as well as provide references for advanced researehe~展开更多
An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by ...An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by surface waves. The water supplied into the test tubes is periodically disturbed by fluctuating a silicon tube before the test section with a speaker and the wavy films absorb the oxygen filled in the tubes. Imposing the periodic disturbance enhances the gas absorption and the enhancement has a maximum at around 20-30 Hz, where the gas absorption is 20-30% higher. Mass transfer coefficients obtained with five tubes agree well with those obtained with single tube. Two-dimensional numerical simulations have also been conducted for gas absorption by wavy film and the enhancement mechanism of the gas absorption is discussed.展开更多
基金Supported by the National Research Council of Science&Technology(NST)grant by the Korea government(MSIP)(No.CRC-15-07-KIER)
文摘Carbon dioxide(CO_2) is greenhouse gas which originates primarily as a main combustion product of biogas and landfill gas. To separate this gas, an inside coated thin film composite(TFC) hollow fiber membrane was developed by interfacial polymerization between 1,3–cyclohexanebis–methylamine(CHMA) and trimesoyl chloride(TMC). ATR-FTIR, SEM and AFM were used to characterize the active thin layer formed inside the PSf hollow fiber. The separation behavior of the CHMA-TMC/PSf membrane was scrutinized by studying various effects like feed gas pressure and temperature. Furthermore, the influence of CHMA concentration and TMC concentration on membrane morphology and performance were investigated. As a result, it was found that mutually the CHMA concentration and TMC concentration play key roles in determining membrane morphology and performance. Moreover, the CHMA-TMC/PSf composite membrane showed good CO_2/CH_4 separation performance. For CO_2/CH_4 mixture gas(30/70 by volume) test, the membrane(PD1 prepared by CHMA 1.0% and TMC 0.5%) showed a CO_2 permeance of 25 GPU and the best CO_2/CH_4 selectivity of 28 at stage cut of 0.1. The high CO_2/CH_4 separation performance of CHMA-TMC/PSf thin film composite membrane was mostly accredited to the thin film thickness and the properties of binary amino groups.
文摘Social media users attracted the attention of scholars at home and abroad.This paper conducted a detailed literature review and prposed an analytical framework to define and conceptualize social media users on the ＂Actual Man＂ theory of Marxism.Furthermore, the paper generalizes three research levels, including the individual level,the gruop level and the materialism level.This study can improve understanding of the users＇ behavior in the social media virtue world as well as provide references for advanced researehe~
基金This work supported by Japan Society for the Promotion of Science (Project No. 13650232).
文摘An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by surface waves. The water supplied into the test tubes is periodically disturbed by fluctuating a silicon tube before the test section with a speaker and the wavy films absorb the oxygen filled in the tubes. Imposing the periodic disturbance enhances the gas absorption and the enhancement has a maximum at around 20-30 Hz, where the gas absorption is 20-30% higher. Mass transfer coefficients obtained with five tubes agree well with those obtained with single tube. Two-dimensional numerical simulations have also been conducted for gas absorption by wavy film and the enhancement mechanism of the gas absorption is discussed.
