A MODEL ON AN ENTRAINED BED-BUBBLING BED PROCESS FOR CO2 CAPTURE FROM FLUE GAS

A simplified model has been developed to investigate effects of important operating parameters on performance of an entrained-bed absorber and bubbling-bed regenerator system collecting CO2 from flue gas. The particle population balance was considered together with chemical reaction to determine the extent of conversion in both absorber and regenerator. Effects of several absorber parameters was tested in a laboratory scale process. The CO2 capture efficiency decreased as temperature or gas velocity increased. However, it increased with static bed height or moisture concentration. The CO2 capture efficiency was exponentially proportional to each parameter. Based on the absolute value of exponent of the parameter, the effect of gas velocity, static bed height, and moisture content was a half, one third, and one fourth as strong as that of temperature, respectively

REACTION CHARACTERISTICS OF TWO WATER GAS SHIFT CATALYSTS IN A BUBBLING FLUIDIZED BED REACTOR FOR SEWGS PROCESS

Reaction characteristics of two WGS catalysts for SEWGS process were investigated in a bubbling fluidized bed reactor. The commercial low temperature WGS catalyst produced by Süd-chemie and new catalyst produced by spray-drying method were used as bed materials. Reaction temperature, steam/CO ratio, and gas velocity were considered as experimental variables. Moreover, long-term operation results of two WGS catalysts were compared as well

THE HOT GAS DESULFURIZATION IN A COMPACT TWO BEDS SYSTEM INTEGRATED WITH COAL GASIFICATION AND FISHER-TROPSCH SYSTEM

The hot gas desulfurization (HGD) technique is one of the elemental technologies of syngas purification having both thermal efficiency and very low emissions. The HGD is a novel method to efficiently remove H2S and COS in the syngas with regenerable sorbents at high temperature and high pressure condition. We propose a compact hot gas desulfurization system by which its operability is improved in stabilizing pressure balances among units. The proposed compact two beds system has two bubbling beds, solid injection nozzle, solid conveying line, and riser. The compact desulfurization system was located between coal gasifier and Fisher-Tropsch (F-T) reactor to desulfurize syngas in order not to deactivate F-T catalyst. To check feasibility of the compact desulfurization system at high pressure condition, both cold mode and hot mode tests have been performed. In the integrated system, the compact desulfurization system has removed H2S and COS in the syngas and supplied the cleaned syngas to the F-T reactor during the continuous operation at high pressure condition

N-(3,4-Difluoro­phen­yl)-N′-(2,5-di­methoxy­phen­yl)urea

In the title compound, C15H14F2N2O3, the dihedral angle between the benzene rings is 64.5 (1)°. One F atom is disordered over two meta positions, with occupancy factors of 0.72 and 0.28. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds involving two N—H and one C=O groups of the urea central fragment, leading to a supra­molecular chain along [011]

The complete chloroplast genome sequence of Abies nephrolepis (Pinaceae: Abietoideae)

AbstractThe plant chloroplast (cp) genome has maintained a relatively conserved structure and gene content throughout evolution. Cp genome sequences have been used widely for resolving evolutionary and phylogenetic issues at various taxonomic levels of plants. Here, we report the complete cp genome of Abies nephrolepis. The A. nephrolepis cp genome is 121,336 base pairs (bp) in length including a pair of short inverted repeat regions (IRa and IRb) of 139 bp each separated by a small single copy (SSC) region of 54,323 bp (SSC) and a large single copy region of 66,735 bp (LSC). It contains 114 genes, 68 of which are protein coding genes, 35 tRNA and four rRNA genes, six open reading frames, and one pseudogene. Seventeen repeat units and 64 simple sequence repeats (SSR) have been detected in A. nephrolepis cp genome. Large IR sequences locate in 42-kb inversion points (1186 bp). The A. nephrolepis cp genome is identical to Abies koreana’s which is closely related to taxa. Pairwise comparison between two cp genomes revealed 140 polymorphic sites in each. Complete cp genome sequence of A. nephrolepis has a significant potential to provide information on the evolutionary pattern of Abietoideae and valuable data for development of DNA markers for easy identification and classification

1-(2,5-Dimeth­oxy­phen­yl)-3-(2-hy­droxy­eth­yl)urea

In the title compound, C11H16N2O4, the 2,5-dimeth­oxy­phenyl moiety is almost planar, with an r.m.s. deviation of 0.026 Å. The dihedral angle between the benzene ring and the plane of the urea moiety is 13.86 (5)°. The mol­ecular structure is stabilized by a short intra­molecular N—H⋯O hydrogen bond. In the crystal, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

1-(2-Hy­droxy­eth­yl)-3-(3-meth­oxy­phen­yl)thio­urea

In the title compound, C10H14N2O3S, the 3-meth­oxy­phenyl unit is almost planar, with an r.m.s. deviation of 0.013 Å. The dihedral angle between the benzene ring and the plane of the thio­urea unit is 62.57 (4)°. In the crystal, N—H⋯O and O—H⋯S hydrogen bonds link the mol­ecules into a three-dimensional network

1-(4-Hy­droxy­phen­yl)-3-(3,4,5-tri­methoxy­phen­yl)thio­urea

In the title compound, C16H18N2O4S, the dihedral angle between the hy­droxy­phenyl ring and the plane of the thio­urea moiety is 54.53 (8)°. The H atoms of the NH groups of thio­urea are positioned anti to each other. In the crystal, inter­molecular N—H⋯S, N—H⋯O, and O—H⋯S hydrogen bonds link the mol­ecules into a three-dimensional network

N-(2,5-Dimeth­oxy­phen­yl)-N′-[4-(2-hy­droxy­eth­yl)phen­yl]urea

In the title compound, C17H20N2O4, the 2,5-dimeth­oxy­phenyl unit is essentially planar, with an r.m.s. deviation of 0.015 Å. The dihedral angle between the benzene rings is 43.66 (4)°. The mol­ecular structure is stabilized by a short intra­molecular N—H⋯O hydrogen bond. In the crystal, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

The anti-aging gene KLOTHO is a novel target for epigenetic silencing in human cervical carcinoma

<p>Abstract</p> <p>Background</p> <p><it>Klotho </it>was originally characterized as an anti-aging gene that predisposed Klotho-deficient mice to a premature aging-like syndrome. Recently, KLOTHO was reported to function as a secreted Wnt antagonist and as a tumor suppressor. Epigenetic gene silencing of secreted Wnt antagonists is considered a common event in a wide range of human malignancies. Abnormal activation of the canonical Wnt pathway due to epigenetic deregulation of Wnt antagonists is thought to play a crucial role in cervical tumorigenesis. In this study, we examined epigenetic silencing of <it>KLOTHO </it>in human cervical carcinoma.</p> <p>Results</p> <p>Loss of <it>KLOTHO </it>mRNA was observed in several cervical cancer cell lines and in invasive carcinoma samples, but not during the early, preinvasive phase of primary cervical tumorigenesis. <it>KLOTHO </it>mRNA was restored after treatment with either the DNA demethylating agent 2'-deoxy-5-azacytidine or histone deacetylase inhibitor trichostatin A. Methylation-specific PCR and bisulfite genomic sequencing analysis of the promoter region of <it>KLOTHO </it>revealed CpG hypermethylation in non-<it>KLOTHO</it>-expressing cervical cancer cell lines and in 41% (9/22) of invasive carcinoma cases. Histone deacetylation was also found to be the major epigenetic silencing mechanism for <it>KLOTHO </it>in the SiHa cell line. Ectopic expression of the secreted form of KLOTHO restored anti-Wnt signaling and anti-clonogenic activity in the CaSki cell line including decreased active β-catenin levels, suppression of T-cell factor/β-catenin target genes, such as <it>c-MYC </it>and <it>CCND1</it>, and inhibition of colony growth.</p> <p>Conclusions</p> <p>Epigenetic silencing of <it>KLOTHO </it>may occur during the late phase of cervical tumorigenesis, and consequent functional loss of KLOTHO as the secreted Wnt antagonist may contribute to aberrant activation of the canonical Wnt pathway in cervical carcinoma.</p