Dynamic measurements of hydrate based gas separation in cooled silica gel

Mingjun Yang,Yongchen Song,Lanlan Jiang,Xiaojing Wang,Weiguo Liu,Yuechao Zhao,Yu Liu,Shanrong Wang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

Hydrate based gas separation is a promising method for carbon dioxide capture. The purpose of thisstudy is to analyze hydrates formation and dissociation characters when gas mixture flows throughcooled silica gel. The additives mixture (THF/SDS) was used to saturate the silica gel partly, and gasmixture (CO2/H2) was injected into it to form hydrates. Magnetic resonance imaging (MRI) images wereobtained using fast spin echo multi-slice pulse sequence. Hydrates saturations were calculatedquantitatively using MRI data. The experimental results showed that the optimal initial solutionsaturation was 34.2% in this investigation. The gas component was analyzed to assess the separationefficiency. For hydrates dissociation processes at 1 atmospheric pressure, CO2 concentrations increasedobviously. Half of the six cycles showed that more than 85.00 mol% CO2 contained in the capture gas, andthe lowest CO2 concentration was 64.83 mol%. Hydrate blockages appeared frequently, which restrictedthe contact of gas and solution and caused the incomplete transformations of residual solution tohydrates. It was a key restricted factor for hydrate based CO2 capture.

Compound heterozygous mutations of NDUFV1 identified in a child with mitochondrial complex I deficiency

Tang Xiaojun,Xu Wuhen,Song Xiaozhen,Ye Haiyun,Ren Xiang,Yang Yongchen,Zhang Hong,Wu Shengnan,Lan Xiaoping 한국유전학회 2022 Genes & Genomics Vol.44 No.6

Background: Mitochondrial complex I deficiency (MCID) is the most common biochemical defect identified in childhood with mitochondrial diseases, mainly including Leigh syndrome, encephalopathy, macrocephaly with progressive leukodystrophy, hypertrophic cardiomyopathy and myopathy. Objective: To identify genetic cause in a patient with early onset autosomal recessive MCID. Methods: Trio whole-exome sequencing was performed and phenotype-related data analyses were conducted. All candidate mutations were confirmed by Sanger sequencing. Results: Here we report a child of Leigh syndrome presented with global developmental delay, progressive muscular hypotonia and myocardial damage. A missense mutation c.118C > T (p.Arg40Trp) and a previously reported mutation c.1157G > A (p.Arg386His) in NDUFV1 have been identified as compound heterozygous in the patient. The mutation p.Arg386His is closely associated with the impairment of 4Fe-4S domain and this mutation has been reported pathogenic. The c.118C > T mutation has not been reported in ClinVar and HGMD database. In silico protein analyses showed that p.Arg40 is highly conserved in a wide range of species, and the amino acid substitution p.Trp40 largely decreases the stability of NDUFV1. In addition, the mutation has not been detected in the Asian populations and it was predicted to be deleterious by numerous prediction tools. Conclusion: This research expands the mutation spectrum of NDUFV1 and substantially provides an early and accurate diagnosis basis of MCID, which would benefit subsequently effective genetic counseling and prenatal diagnosis for future reproduction of the family.

Hydrogen Bonding Analysis of Hydroxyl Groups in Glucose Aqueous Solutions by a Molecular Dynamics Simulation Study

Cong Chen,Wei Zhong Li,Yongchen Song,Lin Dong Weng,Ning Zhang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

Molecular dynamics simulations have been performed to investigate hydrogen bonding characteristics of hydroxyl groups in glucose aqueous solutions with different concentrations. The hydrogen bonding abilities and strength of different O and H atom types have been calculated and compared. The acceptor/donor efficiencies have been predicted and it has been found that: (1) O2-HO2 and O3-HO3 are more efficient intramolecular hydrogen bonding acceptors than donors; (2) O1-HO1, O4-HO4 and O6-HO6 are more efficient intramolecular hydrogen bonding donors than acceptors; (5) O1-HO1 and O6-HO6 are more efficient intermolecular hydrogen bonding acceptors than donors while hydroxyl groups O2-HO2 and O4-HO4 are more efficient intermolecular hydrogen bonding donors than acceptors. The hydrogen bonding abilities of hydroxyl groups revealed that: (1) the hydrogen bonding ability of OH2-Hw is larger than that of hydroxyl groups in glucose; (2) among the hydroxyl groups in glucose, the hydrogen bonding ability of O6-HO6 is the largest and the hydrogen bonding ability of O4-HO4 is the smallest; (3) the intermolecular hydrogen bonding ability of O6-HO6 is the largest; (4) the order for intramolecular hydrogen bonding abilities (from large to small) is O2-HO2, O1-HO1, O3-HO3, O6-HO6 and O4-HO4.

Density measurement and equal density temperature of CO2+brine from Dagang - formation from 313 to 363 K

Yi Zhang,Weiwei Jian,Yangchun Zhan,Yongchen Song,Mingjun Yang,Jiafei Zhao,Yu Liu,Weiguo Liu,Yong Shen 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Densities of CO2+Dagang - formation brine solution were measured by a magnetic suspension balance(MSB) in the pressure range from (10 to 18) MPa, at the temperatures from (313.15 to 363.15) K and CO2 mass frac-tions at 0, 0.0101, 0.0198 and 0.0299. The experimental results revealed that the solution densities increased linearlywith the increasing pressure and CO2 concentration, while decreasing with the increasing temperatures in the experi-mental range. When the temperature increased from (313.15 to 363.15) K, the slopes of the densities versus (vs.) CO2mass fractions decreased from (0.193 to 0.106) g·cm−3. A correlation equation was developed based on thermody-namic theory and experimental data. The absolute average deviation between the correlation equation and the experi-mental data was 0.05%, and the maximum deviation was 0.37% for the density of CO2+water/brine solution in com-mon geological storage conditions. According to the density of CO2 - free brine and apparent molar volume of CO2 inbrine, the equal density temperature (Te) of CO2+Dagang brine solution was obtained at 464.67 K when pressure is10MPa, which means that the density of brine dissolved with CO2 will be less than that of CO2-free brine when thetemperature is higher than 464.67 K at 10MPa. In this work the formation temperature of the Dagang oilfield reser-voir is from 313.15 K to 363.15 K, which is lower than the equal density temperature. Therefore, the safety of CO2 stor-age in Dagang oilfield reservoir can be guaranteed.

Analysis of the 3D Zone of Flow Establishment from a Ship's Propeller

Wei-Haur Lam,Gerard Hamill,Desmond Robinson,Srinivasan Raghunathan,Yongchen Song 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.4

In the present study an experimental investigation of the time-averaged velocity and turbulence intensity distributions from a ship’s propeller, in “bollard pull” condition (zero speed of advance), is reported. Previous studies have focused mainly on the velocity profile of not a rotating ship propeller but a plain jet. The velocity profile of a propeller is investigated experimentally in this study. The velocity measurements were performed in laboratory by using a Laser Doppler Anemometry (LDA). The measurements demonstrated two-peaked ridges velocity profile with a low velocity core at the centre within the near wake. The two-peaked ridges combined to be one-peaked ridge at 3.68 diameters downstream indicating the end of the zone of flow establishment. The study provides useful information from a rotating ship’s propeller rather than a simplified plain jet to researchers investigating flow velocity generated from a propeller and probably resulting local scouring.

WHY PACKAGE TOURS FALL IN POPULARITY:EVIDENCE FROM CHINA’S OUTBOUND TOURISM MARKET

Yong Chen,Markus Schuckert,Haiyan Song,Kaye Chon 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.2

This study develops a model of the market life cycle of package tours, explaining that such tours inherently have low tourist satisfaction which results in a decrease in market share. The model is based on the proposition that tourist satisfaction depends on the extent to which their preferences are fulfilled at the destination, which in turn is determined by their knowledge of its attributes. An analysis of data on China’s outbound tourism market from 1993 to 2010 shows that as tourist satisfaction at the destination increases, the market share of inclusive package tours declines. This suggests that tourist satisfaction can predict tourists’ subsequent choice of a package tour. As tourist satisfaction increases due to the improved information in the market, such package tours will be gradually substituted for independent travel or entirely new packages, or replaced by travel to a new destination.

WHY PACKAGE TOURS FALL IN POPULARITY:EVIDENCE FROM CHINA’S OUTBOUND TOURISM MARKET

Yong Chen,Markus Schuckert,Haiyan Song,Kaye Chon 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.7

This study develops a model of the market life cycle of package tours, explaining that such tours inherently have low tourist satisfaction which results in a decrease in market share. The model is based on the proposition that tourist satisfaction depends on the extent to which their preferences are fulfilled at the destination, which in turn is determined by their knowledge of its attributes. An analysis of data on China’s outbound tourism market from 1993 to 2010 shows that as tourist satisfaction at the destination increases, the market share of inclusive package tours declines. This suggests that tourist satisfaction can predict tourists’ subsequent choice of a package tour. As tourist satisfaction increases due to the improved information in the market, such package tours will be gradually substituted for independent travel or entirely new packages, or replaced by travel to a new destination.