Totally found 10042166 items.

  • [会议] Design and Analysis of Optimized Hybrid Active Power Filter for Electric Arc Furnace Load
    In this paper, the issue of harmonic reduction is comparatively performed and analyzed. PI tuning using GA, PSO, and HSA optimization method is carried out and compared with the THD values for a shunt hybrid active power filter. It has been observed that THD in the magnitudes of current and voltage has been reduced significantly by using the HSA optimization as compared to GA and PSO optimized PI controllers as shown in Table 1. Hence, the proposed analysis verifies the applicability of the optimized hybrid power filtering method for electric arc furnace load variations.
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  • [期刊] Direct dimethyl-ether proton exchange membrane fuel cells and the use of heteropolyacids in the anode catalyst layer for enhanced dimethyl ether oxidation
    In this study, polarization and impedance experiments were performed on a direct dimethyl ether fuel cell (DMEFC). The experimental setup allowed for independent control of water and DME flow rates. The DME flow rate, backpressure, and water flow rate were optimized. Three heteropolyacids, phospho-molybdic acid, H_3PMo_(12)O_(40). (HPMo), phosphotungstic acid, H_3PW_(12)O_(40), (HPW), and silicotungstic acid, H_4SiW_(12)O_(40), (HSiW) were incorporated into the anode catalyst layer in combination with Pt/C Both HPW-Pt and HSiW-Pt showed higher overall performance than the Pt control. Anodic polarizations were also performed, at 30 psig, Tafel slopes of 67 mV dec~(-1), 72 mV dec~(-1), and 79 mV dec~(-1) were found for HPW-Pt, HSiW-Pt and the Pt control, respectively. At Opsig, the Tafel slopes were 56mV dec~(-1), 58 mVdec~(-1), and 65 mVdec~(-1) for HPW-Pt, HSiW-Pt and the Pt control. The trends in the Tafel slope values are in agreement with the polarization data and the electrochemical impedance spectroscopy results. The addition of phosphotungstic acid more than doubled the power density of the fuel cell, compared to the Pt control. When the maximum power density obtained using the HPW-Pt MEA is normalized by the mass of Pt used, the optimal result, 78 mW mg~(-1) Pt, the highest observed at 30 psig and 100 C to date.
  • [会议] Evaluating the Performance of CO2 Foam and CO2 Polymer Enhanced Foam for Heavy Oil Recovery: Laboratory Experiments in Unconsolidated and Consolidated Porous Media
    Enhanced oil recovery(EOR)from heavy oil reservoirs is challenging.The higher viscosity of oil in such reservoirs,add more challenges and severe the difficulties during any EOR method(i.e.high mobility ratio,inadequate sweep,reservoir heterogeneity)compared to that of EOR from light oil reservoirs.Foam has gained interest as one of the EOR methods especially for challenging and heterogeneous reservoirs containing light oil.However,the foam and especially polymer enhanced foam(PEF)potential for heavy oil recovery is less studied. The current study aims to evaluate the performance of CO2 foam and CO2 PEF during heavy oil recovery from both unconsolidated(i.e.sandpack)and consolidate(rock sample)porous media with the help of fluid flow experiments.The injection pressure profile,oil recovery,and CO2 gas production were monitored and recorded to analyze and compare the performance of CO2 foam and PEF for heavy oil recovery.A visual sandpack made of glass column and a core-flood system capable of measuring the pressure at different sections of the core were used in this study.Homogenous and fractured sandstone core samples,as well as a fractured carbonate core sample,were selected for the core-flood study. Static stability results revealed slower liquid drainage and collapse rates for PEF compared to that of foam even in the presence of heavy crude oil.The addition of polymer significantly improved the performance of CO2 foam flooding during heavy oil recovery in dynamic experiments.This result was inferred from faster propagation rate,higher dynamic stability,and higher oil recovery of CO2 PEF over CO2 foam injection. Moreover,the visual analysis demonstrated more stable frontal displacement and higher sweep efficiency of PEF compared to the conventional foam flooding.In the fractured porous media,additional heavy oil recovery was obtained by liquid diversion into the matrix area rather than gas diversion inferred from pressure profile and gas production data. The results obtained from this study show that CO2 PEF could significantly improve the heavy oil recovery and CO2 sequestration,especially in homogeneous porous media. Key Words: CO2 foam,polymer enhanced foam,heavy oil recovery,CO2 sequestration,fractured reservoir
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  • [专利] 一种环保耐沾污海绵砖的制备方法
  • [期刊] Linking bioavailability and toxicity changes of complex chemicals mixture to support decision making for remediation endpoint of contaminated soils
    A six-month laboratory scale study was carried out to investigate the effect of biochar and compost amendments on complex chemical mixtures of tar, heavy metals and metalloids in two genuine contaminated soils. An integrated approach, where organic and inorganic contaminants bioavailability and distribution changes, along with a range of microbiological indicators and ecotoxicological bioassays, was used to provide multiple lines of evidence to support the risk characterisation and assess the remediation end-point. Both compost and biochar amendment (p = 0.005) as well as incubation time (p = 0.001) significantly affected the total and bioavailable concentrations of the total petroleum hydrocarbons (TPH) in the two soils. Specifically, TPH concentration decreased by 46% and 30% in Soil 1 and Soil 2 amended with compost. These decreases were accompanied by a reduction of 78% (Soil 1) and 6% (Soil 2) of the bioavailable hydrocarbons and the most significant decrease was observed for the medium to long chain aliphatic compounds (EC16-35) and medium molecular weight aromatic compounds (EC16-21). Compost amendment enhanced the degradation of both the aliphatic and aromatic fractions in the two soils, while biochar contributed to lock the hydrocarbons in the contaminated soils. Neither compost nor biochar affected the distribution and behaviour of the heavy metals (HM) and metalloids in the different soil phases, suggesting that the co-presence of heavy metals and metalloids posed a low risk. Strong negative correlations were observed between the bioavailable hydrocarbon fractions and the ecotoxicological assays suggesting that when bioavailable concentrations decreased, the toxicity also decreased. This study showed that adopting a combined diagnostic approach can significantly help to identify optimal remediation strategies and contribute to change the over-conservative nature of the current risk assessments thus reducing the costs associated with remediation endpoint.
  • [期刊] Impoundment intensity determines temporal patterns of hydrological fluctuation, carbon cycling and algal succession in a dammed lake of Southwest China
    Hydrological control of lakes has been increasingly practiced in many parts of the world, however, the long-term ecological impact of hydrological regulation and their dependence on lake impoundment intensity has been rarely examined. We combined a spatial survey of surface sediments with sediment core analyses to quantify the limnological changes over the last two centuries for an oligo-mesotrophic lake, which was dammed in 1957 and reinforced during 1987-1990, respectively. A water depth inference model constructed from surface sediment clay components was applied to a well-dated sediment core for water level reconstruction. The inferred water depth increased from 6.2 +/- 0.9 m to 8.7 +/- 1.7 m after dam construction and further to 13.6 +/- 2.6 m after dam enforcement, resulting in an increase in the magnitude of water level fluctuation (WLF). Accordingly, bulk sediment C/N ratio and median grain size spiked in similar to 1957 and similar to 1990, respectively, reflecting a large input of terrestrial sources due to impoundment. With a consistent loss of littoral zone and benthic diatoms over time, a significant decrease in C/N ratio and an abrupt depletion of carbon isotopic signal suggested a shift of carbon transfer towards a pelagic pathway after similar to 1990. While there was a significant increase in algal production since similar to 1990, the accumulation rate of carbon and nitrogen burial displayed an accelerating drop since similar to 1957, reflecting a diluting effect derived from expanding water storage. Furthermore, there was a significant increase in both the ratio between inorganic and organic carbon fluxes and sediment burial of inorganic carbon, reflecting enhanced degradation and low storage of aquatic organic carbon in stratified deep waters since similar to 1990. Hydro-morphological variables were found to exert strong impact on diatom communities, with an increasing interplay with nutrient and climate variables over time. While there existed a significant shift of diatom composition in similar to 1960, species richness and community dissimilarity showed a significant decrease when water depth was raised to above similar to 10 m or the magnitude of WFL was above similar to 2 m. Thus, our sediment surveys provide evidence on the significant impact of lake regulation on hydro morphology, carbon burial and ecological shift over time, as well as its stronger interaction with other forcing with increased impoundment intensity. (C) 2018 Elsevier Ltd. All rights reserved.
  • [专利] 用于镀锌钢的干式润滑剂
  • [期刊] Induction of S-nitrosoglutathione reductase reduces root cadmium uptake by inhibiting Iron-regulated transporter 1
    Background and aimsIncreasing cadmium (Cd) contamination of agricultural soils is a serious problem. Identification of the mechanisms that control Cd uptake by roots is essential if we wish to improve the efficiency of plants in removing Cd from contaminated soils.MethodsWe dissected the role and the mechanism of S-nitrosoglutathione reductase (GSNOR) in regulating root Cd uptake in Arabidopsis plants using GSNOR-related mutants and pharmacological methods.ResultsExposure to Cd stimulated the activity of GSNOR in roots. Both treatment with S-nitrosoglutathione (substrate of GSNOR) in wild-type plants and loss of GSNOR function in gsnor mutants improved expression of IRON-REGULATED TRANSPORTER 1 (IRT1) and increased root Cd uptake, thereby elevating the Cd levels in plants. The opposite patterns were observed in the GSNOR over-expression transgenic plant GSNOR(OE), suggesting a negative regulation of IRT1 expression and Cd uptake by GSNOR. However, both the improvement of Cd uptake owing to S-nitrosoglutathione treatment or GSNOR mutation and the inhibition of Cd uptake due to GSNOR over-expression, could be blocked by loss of function of IRT1 in plants.ConclusionsWe concluded that induction of GSNOR reduced Cd uptake because of its negative regulation of IRT1 in roots, which lowered Cd accumulation in plants.
  • [专利] Antimicrobial composition containing aluminium acetotartrate and a diol.
    (EP-420927) Antimicrobial composition intended to reduce skin irritations especially under napkins. The composition consists of a solution, preferably an aqueous solution, of aluminium acetotartrate and a diol with antimicrobial properties, e.g. propylene glycol.
  • [期刊] 矿用简易除尘器的研究