1,431 research outputs found

    Enhanced Coagulation of Titanium Tetrachloride Aided by the Modified Compound Bioflocculant

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    © 2015 American Society of Civil Engineers. The compound bioflocculant (CBF) was modified by graft copolymerization of acrylic amide and dimethyl diallyl ammonium chloride, and the novel copolymer was denoted as MCBF. The effect of MCBF used as coagulant aid with titanium tetrachloride (TiCl4) was investigated for both high and low molecule weight natural organic matter (NOM) removal. Floc characteristics were studied using a laser diffraction particle-sizing device. Results indicated that the monomers were successfully grafted onto the CBF, and the molecule weight and zeta potential of CBF were greatly improved. The MCBF with TiCl4 exhibited synergistic effect by promoting NOM removal, especially at low TiCl4 doses. Additionally, using MCBF as a coagulant aid with TiCl4 can significantly increase the floc growth rate, size, strength, and broken-floc recoverability. The effect of MCBF on fractal dimension of flocs generated by TiCl4 depended on NOM properties. Both coagulation performance and floc properties were significantly affected by dosing sequence

    Using Linguistic Features to Estimate Suicide Probability of Chinese Microblog Users

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    If people with high risk of suicide can be identified through social media like microblog, it is possible to implement an active intervention system to save their lives. Based on this motivation, the current study administered the Suicide Probability Scale(SPS) to 1041 weibo users at Sina Weibo, which is a leading microblog service provider in China. Two NLP (Natural Language Processing) methods, the Chinese edition of Linguistic Inquiry and Word Count (LIWC) lexicon and Latent Dirichlet Allocation (LDA), are used to extract linguistic features from the Sina Weibo data. We trained predicting models by machine learning algorithm based on these two types of features, to estimate suicide probability based on linguistic features. The experiment results indicate that LDA can find topics that relate to suicide probability, and improve the performance of prediction. Our study adds value in prediction of suicidal probability of social network users with their behaviors

    荧光灯电子调光镇流器的设计与实现

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    2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Magnetoresistance in LaFe11.2Co0.7Si1.1 compound

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    Magnetoresistance has been studied in LaFe/sub 11.2/Co/sub 0.7/Si/sub 1.1/ compound. The ferromagnetic ordering at Curie temperature T/sub C/ of 274 K was found being accompanied by a drastic negative lattice expansion due to the strong structural and magnetic interplay. Such a simultaneous magnetic and lattice change would cause changes in transport properties. The measured transport properties indicate that the transition can be induced by temperature or applied magnetic field. The sample shows a metallic character below T/sub C/, whereas the electrical resistance decreases dramatically and then recovers the metal-like behavior above T/sub C/. Application of a magnetic field retains the transitions via increasing the ferromagnetic ordering temperature. An isothermal increase of field leads to an increase of resistance at temperatures near but above T/sub C/, which is a result of the field-induced metamagnetic transition from paramagnetic to ferromagnetic state.published_or_final_versio

    Removal of natural organic matter by titanium tetrachloride: The effect of total hardness and ionic strength

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    This study is the first attempt to investigate the effect of total hardness and ionic strength on coagulation performance and the floc characteristics of titanium tetrachloride (TiCl4). Membrane fouling under different total hardness and ionic strength conditions was also evaluated during a coagulation-ultrafiltration (C-UF) hybrid process. Coagulation experiments were performed with two simulated waters, using humic acid (HA, high molecular weight) and fulvic acid (FA, relatively low molecular weight), respectively, as model natural organic matter (NOM). Results show that both particle and organic matter removal can be enhanced by increasing total hardness and ionic strength. Floc characteristics were significantly influenced by total hardness and ionic strength and were improved in terms of floc size, growth rate, strength, recoverability and compactness. The results of the UF tests show that the pre-coagulation with TiCl4 significantly improves the membrane permeate fluxes. Under different total hardness and ionic strength conditions, the membrane permeate flux varied according to both NOM and floc characteristics. The increase in total hardness and ionic strength improved the membrane permeate flux in the case of HA simulated water treatment. © 2014 Elsevier Ltd

    Coagulation performance and floc characteristics of polytitanium tetrachloride and titanium tetrachloride compared with ferric chloride for coal mining wastewater treatment

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    © 2015 Elsevier B.V. Abstract The production and discharge of large volumes of wastewater during coal mining activities are one of the major environmental issues in Australia. Therefore, it is crucial to develop and optimise effective treatment processes for the safe disposal of coal mining wastewater (CMWW). In this study, we investigated the performance of a recently developed polytitanium tetrachloride (PTC) coagulant and compared with the performance of titanium tetrachloride (TiCl4) and the commonly used ferric chloride (FeCl3) coagulant for the treatment of CMWW from one of the coal mining sites in Australia. The use of Ti-based coagulants is particularly attractive for the CMWW treatment due to the advantage of being able to recycle the sludge to produce functional titanium dioxide (TiO2) photocatalyst; unlike the flocs formed using conventional coagulants, which need to be disposed in landfill sites. The results showed that both PTC and TiCl4 performed better than FeCl3 in terms of turbidity, UV254 and inorganic compounds (e.g. aluminium, copper or zinc) removal, however, PTC performed poorly in terms of dissolved organic carbon removal (i.e. less than 10%). While charge neutralisation and bridging adsorption were the main coagulation mechanisms identified for TiCl4 treatment; sweep coagulation and bridging adsorption seemed to play a more important role for both PTC and FeCl3 treatments. The flocs formed by PTC coagulation achieved the largest floc size of around 900 μm with the highest floc growth rate. Both Ti-based coagulants (i.e., PTC and TiCl4) showed higher strength factor than FeCl3, while TiCl4 coagulant yielded the flocs with the highest recovery factor. This study indicates that Ti-based coagulants are effective and promising coagulants for the treatment of CMWW

    Vertical Bearing Capacity of a Partially-Embedded Pipeline on Tresca Soils

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    Slip-line field solutions are presented for the ultimate load of submarine pipelines on a purely cohesive soil obeying Tresca yield criterion, taking into account of pipe embedment and pipe-soil contact friction. The derived bearing capacity factors for a smooth pipeline degenerate into those for the traditional strip-line footing when the embedment approaches zero. Parametric studies demonstrate that the bearing capacity factors for pipeline foundations are significantly influenced by the pipeline embedment and the pipe-soil frictional coefficient. With the increase of pipeline embedment, the bearing capacity factor Nc decreases gradually, and finally reaches the minimum value (4.0) when the embedment equals to pipeline radius. As such, if the pipeline is directly treated as a traditional strip footing, the bearing capacity factor Nc would be over evaluated. The ultimate bearing loads increase with increasing pipeline embedment and pipe-soil frictional coefficient

    Biocompatible FeOOH-Carbon quantum dots nanocomposites for gaseousNOx removal under visible light: Improved charge separation and Highselectivity

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    Development of biocompatible photocatalysts with improved charge separation and high selectivity is essential for effective removal of air pollutants. Iron-containing catalysts have attracted extensive attention due to their low-toxicity and high natural abundance. Here, carbon quantum dots (CQDs) modified FeOOH nanocomposites fabricated using a facile hydrothermal route showed enhanced NO removal efficiency (22%) compared to pure FeOOH. Moreover, generation of toxic NO2&nbsp;intermediates was significantly inhibited using the nanocomposites, demonstrating high selectivity for final nitrate formation. Photo-electrochemical results showed that both charge separation and transfer efficiency were significantly improved by CQDs addition, and the lifetime of photo-generated carriers was increased eventually. Density functional theory calculations further elucidated that the suppressed recombination of photo-induced electron-hole pairs was due to enhanced electron migration from the FeOOH to CQDs. A NO degradation mechanism was proposed based on detection of the reactive oxygen species using electron paramagnetic spectroscopy. In addition, the nanocomposite showed good biocompatibility and low cytotoxity, ensuring minimal environmental impact for potential application in large-scale.</span

    Effect of remote ischemic preConditioning on liver injury in patients undergoing liver resection: the ERIC-LIVER trial

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    OBJECTIVE: Novel hepatoprotective strategies are needed to improve clinical outcomes during liver surgery. There is mixed data on the role of remote ischemic preconditioning (RIPC). We investigated RIPC in partial hepatectomy for primary hepatocellular carcinoma (HCC). METHODS: This was a Phase II, single-center, sham-controlled, randomized controlled trial (RCT). The primary hypothesis was that RIPC would reduce acute liver injury following surgery indicated by serum alanine transferase (ALT) 24 h following hepatectomy in patients with primary HCC, compared to sham. Patients were randomized to receive either four cycles of 5 min/5 min arm cuff inflation/deflation immediately prior to surgery, or sham. Secondary endpoints included clinical, biochemical and pathological outcomes. Liver function measured by Indocyanine Green pulse densitometry was performed in a subset of patients. RESULTS: 24 and 26 patients were randomized to RIPC and control groups respectively. The groups were balanced for baseline characteristics, except the duration of operation was longer in the RIPC group. Median ALT at 24 h was similar between groups (196 IU/L IQR 113.5-419.5 versus 172.5 IU/L IQR 115-298 respectively, p = 0.61). Groups were similar in secondary endpoints. CONCLUSION: This RCT did not demonstrate beneficial effects with RIPC on serum ALT levels 24 h after partial hepatectomy
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