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Effects of slag fineness on durability of mortars
TOPÇU Ilker Bekir, BİLİR Turhan
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1725-1730.
https://doi.org/10.1631/jzus.2007.A1725
In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS) replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects, exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.
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Cyclic behavior test of a new double-arch steel gate
LUO Yao-zhi, ZHU Shi-zhe, CHEN Xi
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1731-1739.
https://doi.org/10.1631/jzus.2007.A1731
A new double-arch structure for the gate used as tidal barrage and sluice was adopted in Caoe River Dam in China. It was a spatial structure made up of the right arch, the invert arch, the chord, etc., and was designed to bear bilateral loads. To research the cyclic behavior of the new double-arch structure, a scale-model cyclic test was conducted. First, the test setup and test method were presented in detail, and according to the test results, the cyclic behavior and failure characteristics of this structure were discussed. Then by analyzing the test cyclic envelope curve, it was found the curve was divided into three stages: the elastic stage, the local plastic stage and the failure stage at the local yield point and structural yield point. The gate model has local yield strength and structural yield strength, with both their values being bigger than that of the designing load. Therefore, the gate is safe enough for the projects. At last, dynamic property of the gate was analyzed considering additional mass of the water. It was found that the tidal bore shock would not cause resonance vibration of the gate.
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Competitive adsorption of Cd, Cu, Hg and Pb by agricultural soils of the Changjiang and Zhujiang deltas in China
ZHANG Ming-kui, ZHENG Shun-an
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1808-1815.
https://doi.org/10.1631/jzus.2007.A1808
Soils can often be contaminated simultaneously by more than one heavy metal. The sorption-desorption behavior of a metal in a soil will be affected by the presence of other metals. Therefore, selective retention and competitive adsorption of the soils to heavy metals can affect their availability and movement through the soils. In this study, the simultaneous competitive adsorption of four heavy metals (Cd, Cu, Hg, and Pb) on ten agricultural soils collected from the Changjiang and Zhujiang deltas, China was assessed. The results showed that the competition affected the behavior of heavy metal cations in such a way that the soils adsorbed less Cd and Hg, and more Pb and Cu with increasing total metal concentrations, regardless of the molar concentration applied. As the applied concentrations increased, Pb and Cu adsorption increased, while Cd and Hg adsorption decreased. The adsorption sequence most found was Pb>Cu>Hg>Cd. The maximum adsorption capacity for the heavy metal cations was calculated, and affected markedly by soil properties. The results suggest that Hg and Cd have higher mobility associated to the lower adsorption and that Pb and Cu present the opposite behavior. Significant correlations were found between the maximum adsorption capacity of the metals and pH value and exchangeable acid, suggesting that soil pH and exchangeable acid were key factors controlling the solubility and mobility of the metals in the agricultural soils.
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Environmental damage costs from fossil electricity generation in China, 2000~2003
ZHANG Qing-yu, WEI Yu-mei, CHEN Ying-xu, GUO Hui
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1816-1825.
https://doi.org/10.1631/jzus.2007.A1816
Electricity consumption increases rapidly with the rapid development of China. The environmental damage costs of electricity generation are very important for both policy analysis and the proper management of the environment. A method was developed in this work to estimate gross environmental damage costs according to emission inventory and environmental cost factors, and to extend the costs from provincial to national level with population density. In this paper, sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter less than 10 μm in diameter (PM10), and carbon dioxide (CO2) from fossil fired power plants over 6000 kW were selected as index pollutants to quantify the environmental costs of damages on human health and global warming. With the new developed method, environmental damage costs, caused by 3 types of fired power plants in 30 provinces and 6 economic sectors during the years 2000 to 2003, were evaluated and analyzed. It can be seen that the calculated total national environmental damage costs of electricity have rapidly increased from 94930.87×106 USD in 2000 to about 141041.39×106 USD in 2003, with an average annual growth rate of 14.11%. Environmental damage costs of SO2, NOx, PM10, and CO2 are 69475.69×106, 30079.29×106, 28931.84×106, and 12554.57×106 USD and account for 49.26%, 21.33%, 20.51%, and 8.90% of total environmental costs in fossil electricity generation, respectively. With regard to regional distribution, external costs caused by fossil electricity generation are mainly concentrated in the more populated and industrialized areas of China, i.e., the Eastern Central and Southeastern areas.
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Removal of cyclops in pre-oxidizing cooperation water treatment process
LIU Dong-mei, CUI Fu-yi, WU Ya-qin, LIN Tao, ZHANG Min, YU Ming-xue
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1826-1830.
https://doi.org/10.1631/jzus.2007.A1826
Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine (Cl2), chlorine dioxide (ClO2), ozone (O3), hydrogen peroxide (H2O2), ozone/hydrogen peroxide (O3/H2O2), chloramines (Cl2-NH3) and potassium permanganate (KMnO4). The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone, ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated. The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks.
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Petrochemical wastewater treatment with a pilot-scale bioaugmented biological treatment system
ZHAO Li-jun, MA Fang, GUO Jing-bo, ZHAO Qing-liang
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1831-1838.
https://doi.org/10.1631/jzus.2007.A1831
In solving the deterioration of biological treatment system treating petrochemical wastewater under low temperatures, bioaugmentation technology was adopted by delivering engineering bacteria into a pilot-scale two-stage anoxic-oxic (A/O) process based on previous lab-scale study. Experimental results showed that when the concentrations of COD and NH4+-N of the influent were 370~910 mg/L and 10~70 mg/L, the corresponding average concentrations of those of effluent were about 80 mg/L and 8 mg/L respectively, which was better than the Level I criteria of the Integrated Wastewater Discharge Standard (GB8978-1996). According to GC-MS analysis of the effluents from both the wastewater treatment plant (WWTP) and the pilot system, there were 68 kinds of persistent organic pollutants in the WWTP effluent, while there were only 32 in that of the pilot system. In addition, the amount of the organics in the effluent of the pilot system reduced by almost 50% compared to that of the WWTP. As a whole, after bioaugmentation, the organic removal efficiency of the wastewater treatment system obviously increased.
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Catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 in NO+CO reaction
JIANG Xiao-yuan, DU Feng, ZHANG Xu, JIA Yan-rong, ZHENG Xiao-ming
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1839-1845.
https://doi.org/10.1631/jzus.2007.A1839
Using SnxTi1−xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO+CO reaction system and the methods of BET (Brunauer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1−xO2 mixed oxides could be reductive.
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Effects of N source and nitrification pretreatment on growth of Arthrospira platensis in human urine
FENG Dao-lun, WU Zu-cheng, WANG Da-hui
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1846-1852.
https://doi.org/10.1631/jzus.2007.A1846
Culture of Arthrospira platensis (Spirulina platensis) in human urine was investigated to get valuable biomass. NO3-N was the proper N source, in comparison with other N source, including urea, NH4-N and NO2-N. As a result, aerobic nitrification of human urine was performed, with above 93.6% nitrification percentage finally achieved with total-N (TN) load of 46.52 mg/(L·d), in which Arthrospira platensis was successfully grown. The main compositions of the obtained biomass are close to those in Zarrouk medium. Thus, it is possible to culture Arthrospira platensis in nitrified human urine for food production within bioregenerative life support systems (BLSSs).
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Sands modeling constrained by high-resolution seismic data
ZHANG Feng, LI Zhi-ping, WANG He-lin, WU Jian, TAN Zhen-hua
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1858-1863.
https://doi.org/10.1631/jzus.2007.A1858
In the phase of field evaluation, the changing of interwell reservoir may be out of control if the geological model was built only on well data due to few existing wells. The uncertainty of the interwell reservoir interpolation based only on well data can be decreased by comprehensive utilization of geological, logging and seismic data, especially by using highly relative seismic properties from 3D seismic data adjusted by well point data to restrict interpolation of geological properties. A 3D-geological model which takes the sand body as the direct modeling object was built through stacking the structure, reservoir and water/oil/gas properties together in 3D space.
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Study on source rock potential and source rocks spatial distribution in the Manghan Faulted Sag, Kailu Basin
YIN Zhi-jun, ZHANG Feng, ZOU Hua-yao, WANG Wei-xing, ZHOU Lian-min, CHEN Hua-lin
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2007, 8(11): 1872-1878.
https://doi.org/10.1631/jzus.2007.A1872
Manghan Faulted Sag is an exploratory target area in Kailu Basin. In order to determine its exploration prospect, the effectiveness of its source rocks is evaluated by organic geochemical behavior analysis of the samples, and their distributions are predicted using trace integration seismic inversion technology. Studies on their organic matter abundance, type and maturity indicate that the source rocks in the Sag have great generating potentials. Furthermore, it is found that, based on the spatial distribution predication, the source rocks in the Sag are well developed. Therefore, the Sag has a promising prospect for exploration.
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22 articles
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