The thermal degradation and flammability of ordinary area (OA) and coating band (CB) of low ignition propensity (LIP) cigarette paper were compared using scanning electron microscopy (SEM), real-time Fourier transform infrared (RT-FTIR), thermogravimetric/Fourier transform infrared spectrometry (TG-FTIR) and microscale combustion calorimeter (MCC), respectively. SEM results showed that only the compactly packed particles, instead of fibers exposed on the surface of OA, could be seen on the surface of CB. And it is at the whole temperature range that there are still many closely packed particles on the surface of CB. The results of thermal degradation displayed that C-H and C-O bonds in CB displayed higher thermal stabilities than those in OA. And the comparison of the evolution of their gaseous products manifested that the emission of many gas products of CB like methane, hydrocarbons, aldehydes, CO and alcohols were obviously lower than those of OA. Furthermore, some evaporated species like alkanes, CO, carbonyl compounds and alcohols escaped earlier than those of OA. Their flammability results demonstrated that both peak heat release rate (PHRR) and total heat release (THR) of CB above 270 degrees C in the degradation step of cellulose and the following char decomposition were lower than those of OA. (C) 2014 Elsevier B.V. All rights reserved.
Zhou, Shun
Huang, Wenwen
Belton, David J.
Simmons, Leo O.
Perry, Carole C.
Wang, Xiaoqin
Kaplan, David L.
In the present study, an artificial spider silk gene, 6mer, derived from the consensus sequence of Nephila clavipes dragline silk gene, was fused with different silica-binding peptides (SiBPs), A1, A3 and R5, to study the impact of the fusion protein sequence chemistry on silica formation and the ability to generate a silk silica composite in two different bioinspired silicification systems: solution solution and solution solid. Condensed silica nanoscale particles (600-800 nm) were formed in the presence of the recombinant silk and chimeras, which were smaller than those formed by 15mer-SiBP chimeras [1], revealing that the molecular weight of the silk domain correlated to the sizes of the condensed silica particles in the solution system. In addition, the chimeras (6mer-A1/A3/R5) produced smaller condensed silica particles than the control (6mer), revealing that the silica particle size formed in the solution system is controlled by the size of protein assemblies in solution. In the solution-solid interface system, silicification reactions were performed on the surface of films fabricated from the recombinant silk proteins and chimeras and then treated to induce beta-sheet formation. A higher density of condensed silica formed on the films containing the lowest beta-sheet content while the films with the highest beta-sheet content precipitated the lowest density of silica, revealing an inverse correlation between the beta-sheet secondary structure and the silica content formed on the films. Intriguingly, the 6mer-A3 showed the highest rate of silica condensation but the lowest density of silica deposition on the films, compared with 6mer-A1 and -R5, revealing antagonistic crosstalk between the silk and the SiBP domains in terms of protein assembly. These findings offer a path forward in the tailoring of biopolymer silica composites for biomaterial related needs. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Zhou, Shun
Zhao, Honggang
Thongda, Wilawan
Zhang, Dongdong
Su, Baofeng
Yu, Dan
Peatman, Eric
Li, Chao
Highlights • Twelve galectin genes were identified in channel catfish. • Galectin genes were ubiquitously expressed in catfish tissues. • Galectin genes were significantly induced after bacterial challenge. Abstract Galectins, a family of β-galactoside-binding lectins with conserved CRDs, which can recognize the glycans on the surface of viruses, bacteria and protozoan parasites, are emerging as key players in many important pathological processes, including acute and chronic inflammatory diseases, autoimmunity and apoptosis. Although galectins have attracted great interest in mammals, they are still poorly-characterized in teleost. Previously, several studies have reported their high expression levels in mucosal tissues before and post infection. Given the important roles for galectins in mucosal immunity, therefore, we characterized the galectin gene family and profiled family member expression after challenge with two different Gram-negative bacterial pathogens. Here, twelve galectins genes were captured in channel catfish (Ictalurus punctatus), and phylogenetic analysis showed the strongest relationship to zebrafish and salmon, which is consistent with their phylogenetic relationships. Furthermore, the galectin genes were widely expressed in catfish tissues, while most of the galectin genes were strongly expressed in mucosal tissues (skin, gill and intestine). In addition, the expression profiles of galectins after bacterial infection varied depending on both pathogen and tissue type, suggesting that galectins may exert disparate functions or exhibit distinct tissue-selective roles in the host immune response to bacterial pathogens. Further studies are needed, however, to expand functional characterization and examine whether galectins may also play additional physiological roles in catfish immunity.
Zhou, Shun
Wang, Xiaofeng
Ning, Min
Guo, Dongfeng
Zhang, Yaping
He, Qing
Bao, Sui
Tian, Zhenfeng
Xu, Yingbo
Hu, Yuan
Highlights • CO yields of flue-cured tobacco under the low-temperature heating conditions were quantitatively evaluated using SSTF. • The effects of temperature, air velocity and elemental compositions on CO yields were studied, respectively. • Temperature slightly influenced CO yield of heated tobacco at a fixed air velocity. • CO yield, with reducing air velocity, first increased fast and then tended to remain unchanged at a fixed temperature. • K/S is a very important factor influencing CO yields of heated tobacco. Abstract In this paper, the quantitative evaluation of CO yields of flue-cured tobacco under the low-temperature heating conditions was investigated using a steady state tube furnace (SSTF) on the basis of controlled equivalence ratio method. Then the effect of temperature, ventilation condition and elemental compositions on the CO yields was studied, respectively. There was a strikingly low CO yield of heated tobacco under a fixed ventilation condition in comparison with flaming or even smouldering tobacco, and the temperature just slightly influenced the CO yield of flue-cured tobacco under the low-temperature heating states. At a fixed temperature of 450 °C, the CO yield, with reducing air velocity, first increased fast and then tended to remain unchanged. The correlation study indicates that there were no significant relationships between CO yields and the individual element except for the content of carbon and hydrogen, while the significant negative correlations of CO yields with the ratio of potassium to sulphur (K/S) at the 0.01 level appeared. Further random-Forest analysis revealed that K/S is another important factor influencing CO yields of fuel-cured tobacco under the externally heated pyrolysis conditions after hydrogen content.
A water purification system (100) including an inlet (110) configured to accept a flow of water (105) is provided. The system (100) includes a KDF filtration stage (120) fluidly connected to the inlet (110) and including a metal alloy including elemental copper and elemental zinc. The system (100) includes a reverse osmosis stage (140) fluidly connected to the KDF stage (120). The system (100) also includes an outlet (150) fluidly connected to the reverse osmosis stage (140) and configured to output a flow of purified water (155). The reverse osmosis stage (140) is downstream of the KDF stage (120). A method of purifying water is also provided.
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