期刊：
Journal of Reinforced Plastics and Composites,2017年36(22):1665-1679 ISSN：0731-6844
通讯作者：
Xiao, Xiao
作者机构：
[Xiao, Xiao] Univ South China, Sch Civil Engn, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.;[Zhang, Zhujing; Bai, Yu] Monash Univ, Dept Civil Engn, Clayton, Vic, Australia.
通讯机构：
[Xiao, Xiao] U;Univ South China, Sch Civil Engn, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
Cyclic behaviour;energy dissipation;pultruded GFRP frame;bonded sleeve connection;finite element analysis
摘要：
This paper presents a comparative study on the energy dissipation capacity of one glass fibre-reinforced polymer frame with bonded sleeve connection and steel frames with bolted endplate connections. Experimentally measured moment-rotation behaviour of a typical bonded sleeve connection was employed to develop the joint model for the glass fibre-reinforced polymer frame. In order to reduce the effect of the different beam size on the overall frame behaviour, the size of the steel profiles was selected to be equal, less than and greater than glass fibre-reinforced polymer profile in terms of the bending stiffness. The moment–rotation response of bolted endplate connection was then theoretically determined through Mohammadi’s design model. The frame models were developed using 3D beam elements and nonlinear spring elements. Comparing the energy dissipation capacity between glass fibre-reinforced polymer and steel frames at connections and floors, it was found that although glass fibre-reinforced polymer members were lack of ductility, the glass fibre-reinforced polymer frame can give satisfactory energy dissipation capacity that is comparable to steel frames. The energy dissipation capacity of glass fibre-reinforced polymer frame can be induced by the yielding of steel endplate from bonded sleeve connection.
作者机构：
[Xie, Dong; Wang, Yun; Mo, Shunquan; Liao, Maili] Univ South China, Sch Urban Construct, Hengyang 421001, Peoples R China.;[Xie, Dong; Wang, Hanqing] Cent S Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Wang, Hanqing] Hunan Univ Commerce, Changsha 410205, Hunan, Peoples R China.
通讯机构：
[Xie, Dong] U;Univ South China, Sch Urban Construct, Hengyang 421001, Peoples R China.
关键词：
CFD;Capillary ceiling radiant cooling panel;Cooling capacity;Distribution of temperature non-uniformity;Numerical analysis
摘要：
Capillary ceiling radiant cooling panel is a high temperature cooling system, which could pose low energy consumption to meet thermal comfort requirements. A computational fluid dynamics (CFD) simulation study on heat transfer of chilled water flow in the capillary of ceiling radiant cooling panel was performed to attain surface temperature distributions and cooling capacities. Six influencing factors included chilled water inlet parameters, conditions of gypsum plaster and capillary mats structural parameters were considered to obtain the complicated relationships between capillary radiant panel conditions and heat transfer performance. The index of temperature non-uniformity coefficient was proposed to evaluate temperature profiles of ceiling panel surface. The results of the simulation were compared with the values depicted in ASHRAE Handbook and good agreement had been achieved. The average difference between simulation results and the values reported by ASHRAE handbook was within the region of 15%. The research results showed that temperature non-uniformity coefficient was negatively correlated with temperature of chilled inlet water (linear correlation), water velocity (correlation coefficient R = -0.85), and pipe diameter (correlation coefficient R = -0.93), but positively and linearly correlated with tube spacing. Cooling capacity was found to have negative linear correlation with temperature of chilled inlet water, covering thickness and tube spacing. (C) 2015 Elsevier Ltd. All rights reserved.
摘要：
Anaerobic ammonium-oxidizing (anammox) process is considered to be a sustainable option for nitrogen removal. Application of this process, however, is limited by the availability of high strength nitrogen. In this study, an anaerobic ammonium oxidation (ANAMMOX) biofilter to treat sewage was deployed at ambient temperatures (18-21.5 degrees C), and the corresponding microbial community was investigated. The ammonia and nitrite initial loading rates were 0.154 kgN/(m(3) d) and 0.2 kgN/(m(3) d), respectively. ANAMMOX bacteria were rapidly enriched within 25 days and achieved a sustainable increase in the nitrogen removal rate (NRR) for sewage treatment. A final NRR of 0.99 kgN/(m(3) d) was seen at the 80 day point. Observations that combined fluorescence in situ hybridization (FISH) analysis with scanning electron microscopy (SEM) observations confirmed that ANAMMOX bacteria were dominant in the cultivated biofilm, accounting for 39.5 (+/- 1.6)% of total bacteria. Denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis identified five genera of bacteria: Pseudomonas, Acinetobacter, Nitrosomonas, Candidatus Brocadia fulgida and Ferruginibacter. Of these, Candidatus Brocadia fulgida was the functional ANAMMOX bacteria in the reactor. Candidatus Brocadia fulgida could survive comfortably in sewage, and co-existed with Nitrosomonas and denitrifying bacteria. (C) 2016 Elsevier Ltd. All rights reserved.
摘要：
Anthraquinone-2-sulfonate (AQS) was employed in humus substitutes to evaluate the effects and influencing factors of U(VI) reduction-by Shewanella oneidensis MR-1 (S. oneidensis MR-1) under anaerobic-condition. The removal rate of U(VI) at 30 ℃ reaches 99.0% afterd 96 h with the pH value of 7.0 and AQS concentration of 1.0 mmol/L. The effective concentrations of AQS as the accelerator for U(VI) bioreduction are approximately 0.5-1.0 mmol/L. The bioreduction of U(VI) is inhibited when the concentration of AQS exceeds 2.0 mmol/L. The coexistence of ions, such as Cu~(2+), Cr~(6+), Mn~(2+), shows a remarkable negative effect on the U(VI) reduction, and Zn~(2+) shows less influence on the process compared with other tested ions. The U(VI) reduction is remarkably inhibited when the concentration of nitrate ion exceeds 1.0-mmol/L. Otherwise, no difference is found when the nitrate ion concentration is less than 0.5 mmol/L. Sulfate ion (<5.0 mmol/L) slightly promotes the U(VI) reduction. Zero-valent iron (ZVI) promotes the U(VI) reduction by S. oneidensis, and the reduction rate improves with increasing the amount of ZVI in the range of 0-2.0 g/L. The XPS result indicates that uranium deposits on the cell surface are in U(VI) and U(IV) forms, and the majority of uranium in the solution is stable UO_2.
摘要：
Phenolic wastewater comes mainly from coking, gas, and petrochemical plants, and other industrial sectors, as well as petroleum cracking ethylene, synthetic phenol, poly Thalidomide fibers, organic pesticides, and the phenolic resin production process. Phenolic compounds are monitoring our priority persistent organic compounds, having already been included in the column of carcinogenic single ring aromatics. In this paper, catalytic supercritical water gasification was applied to treat the phenolic wastewater. The influence of alkali on the gasification of phenolic wastewater with NaOH as catalyst at 580 degrees C, 27MPa was investigated. The results showed that the NaOH addition increased H-2 fraction and gas yield. The reaction mechanism was analyzed.
期刊：
Water Science and Technology,2015年71(5):725-733 ISSN：0273-1223
通讯作者：
Li Dong
作者机构：
[Xie Shuibo; Liu Yingjiu; Zeng Taotao] Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reu, Hengyang 421001, Peoples R China.;[Zhang Jie; Zeng Huiping; Li Dong] Beijing Univ Technol, Key Lab Beijing Water Qual Sci & Water Environm R, Beijing 100124, Peoples R China.;[Qiu Wenxin] Beijing Gen Municipal Engn Design & Res Inst Co L, Beijing 100082, Peoples R China.;[Zhang Jie] Harbin Inst Technol, State Key Lab Urban Water Resource & Environm, Harbin 150090, Peoples R China.
通讯机构：
[Li Dong] B;Beijing Univ Technol, Key Lab Beijing Water Qual Sci & Water Environm R, Beijing 100124, Peoples R China.
摘要：
An upflow anaerobic biofilter (AF) was developed to investigate anaerobic ammonium-oxidizing (ANAMMOX) efficiency in treating low-strength wastewater at ambient temperature (15.3-23.2 degrees C). Denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization were used to investigate treatment effects on the microbial community. Stepwise decreases in influent ammonia concentration could help ANAMMOX bacteria selectively acclimate to low-ammonia conditions. With an influent ammonia concentration of 46.5 mg/L, the AF reactor obtained an average nitrogen removal rate of 2.26 kg/(m(3) day), and a removal efficiency of 75.9%. polymerase chain reaction-DGGE results showed that microbial diversity in the low matrix was greater than in the high matrix. Microbial community structures changed when the influent ammonia concentration decreased. The genus of functional ANAMMOX bacteria was Candidatus Kuenenia stuttgartiensis, which remained stationary across study phases. Visual observation revealed that the relative proportions of ANAMMOX bacteria decreased from 41.6 to 36.3% across three study phases. The AF bioreactor successfully maintained high activity due to the ANAMMOX bacteria adaptation to low temperature and substrate conditions.
摘要：
In order to investigate the mechanism of extracellular polymeric substances (EPS) influencing sludge characteristics, variations of extractable EPS from municipal sewage sludge by acid/alkaline pretreatment and gamma-ray irradiation were studied. The changes in constituents of EPS were analyzed by UV-vis spectra and SEM images. The effects of alkaline pretreatment and gamma-ray irradiation on the functional groups in EPS were investigated by Fourier transform infrared (FTIR) spectrometer. Results showed that the extractable EPS increased clearly with increasing irradiation dose from 0 to 15 kGy. UV-vis spectra indicated that a new absorption band from 240 nm to 300 nm existed in all irradiated samples, apart from acid condition. The results of FTIR spectroscopic analysis indicated that, irradiation influenced major functional groups in EPS, such as protein and polysaccharide, and these effects were clearer under alkaline condition. SEM images provided that after alkaline hydrolysis, gamma-ray irradiation was more effective in resulting in the sludge flocs and cells broken, compared with acid pretreatment (pH 2.50). (c) 2013 Published by Elsevier Ltd.
关键词：
Dunkirk sediments;compressibility;compressive strength behaviour;lime;shear strength test;triaxial test
摘要：
The increasing cost associated with high-quality materials has lead to the need for sediments to be treated and then used in road construction in the context of durable development. Therefore, the modification and stabilisation of Dunkirk marine sediments by using lime is necessary to study for their potential use in road construction. Based on the physical characteristics of untreated sediments, a series of laboratory tests to investigate the geotechnical properties of untreated sediments and lime-treated sediments, such as unconfined compressive strength tests, standard oedometer tests, direct shear tests and triaxial tests, were performed. Lime was added in percentages of 3% and 6%, by weight of dry sediments. The test results show a significant improvement in unconfined compressive strength and shear strength due to the addition of lime. From the strain–stress relationship of compressive strength tests, it can be found that the failure mode of solidified sediments develops gradually from plastic failure to brittle failure, while the failure strength increases and the failure strain decreases with lime content. Compared with untreated sediments, the shear strength parameters of solidified sediments determined by direct shear tests, such as internal friction angle and cohesion, are increased owing to the pozzolanic reaction between lime and clay minerals. Using the oedometer apparatus, it is observed that after lime treatment, the preconsolidation pressure, the coefficient of consolidation and the compression index are increased, while the swelling index is decreased. The characteristics of the deviator stress–axial strain relation and the pore water pressure distribution under different confining stresses are compared with untreated and treated sediments, and the effect of lime content on cohesion and internal friction angle determined by triaxial tests is discussed.
