242 research outputs found
Special Issue on Superhydrophobic coatings for corrosion and tribology
No full textSuperhydrophobicity, showing strong water-repellency, has been widely investigated for many applications, especially in the fields of corrosion protection and antifouling. Water tends to roll off from superhydrophobic surfaces like natural lotus leaves. When a corrosive aqueous solution comes into contact with such a surface, a stable air cushion is formed on the interface between liquid and solid which minimizes the contact area. As a result, the charge transfer of the corrosive reaction is dramatically restrained, resulting in a positively shifted corrosion potential and low corrosion rate. Additionally, the superhydrophobic surface effectively isolates microorganisms from adhering on the surface and thus prevents microbiologically influenced corrosion caused by their metabolites. Thus, the superhydrophobic coatings have potential applications in corrosion protection of marine equipment, medical devices, mechanical components, etc.However, the lack of mechanical strength and heat resistance prevents the use of these coatings in harsh environments. It is well established that micro-nano hierarchical structures and low surface energy are the two fundamental factors crucial to developing superhydrophobic surfaces, and the superhydrophobicity of these surfaces would be diminished if they were destroyed by abrasion or overheating. The superhydrophobic coatings using wear-resistant inorganic materials are therefore highly sought after. Ceramics are of particular interest due to their high mechanical strength, heat and corrosion resistance. Such superhydrophobic coatings have recently been successfully fabricated using a variety of ceramics and different approaches, and have shown improved wear and tribocorrosion resistance properties.This special issue is making the best effort to reflect the recent developments in the fabrication of superhydrophobic coatings and their robustness against corrosion and wear resistance. We hope it will stimulate the future research and application
Early Cretaceous continental delamination in the Yangtze Block: evidence from high-Mg adakitic intrusions along the Tanlu fault, central Eastern China
No full textAbstract not availableLiqiong Jia, Xuanxue Mo, M. Santosh, Zhusen Yang, Dan Yang, Guochen Dong, Liang Wang, Xinchun Wang, Xuan W
One-step electrodeposition of a self-cleaning and corrosion resistant Ni/WS2 superhydrophobic surface
No full textSuperhydrophobic surfaces have been intensively investigated for applications requiring self-cleaning and corrosion resistance. The techniques used to fabricate such a coating tend to be costly, time and energy consuming; further surface modification steps are often needed. In this study, a superhydrophobic composite electrodeposit based on tungsten disulphide nanoparticles dispersed in nickel on a mild steel substrate was successfully developed. At room temperature, the deposit showed a water contact angle of 158.3 deg and a sliding angle of 7.7 deg. The effects of operational parameters on surface morphology and superhydrophobicity are discussed. Compared to the substrate, the robust surface of the as-prepared coatings exhibited good self-cleaning and corrosion resistance, providing potential for industrial applications
Electroplating of non-fluorinated superhydrophobic Ni/WC/WS<sub>2</sub> composite coatings with high abrasive resistance
No full textWeak hierarchical rough structures on superhydrophobic surfaces hinder their practical industrial applications. This paper reports a strategy to fabricate robust nickel-based superhydrophobic coatings via the codeposition of nanosized WS2 and WC particles. The Ni/WC/WS2 composite coatings were synthesized on mild steel substrates by one-pot electroplating followed by the adsorption of stearic acid self-assembled monolayers to modify the surface wetting. The particle concentration in the bath was investigated and the maximum water contact angle of approx. 170° was achieved by optimizing the particle contained. Hardened by WC and lubricated by WS2 inclusions the superhydrophobic coatings showed remarkable abrasive resistance with a bearing capacity ≥10,000 mm abrasion length. The coatings also showed aerophilic behavior and good environmental stability over >6 months
Robust Ni/WC superhydrophobic surfaces by electrodeposition
No full textSuperhydrophobic, water repellent surfaces have attracted much attention but poor surface mechanical properties have limited their wider practical application. Robust surfaces based on nickel-tungsten carbide composite coatings have been electrodeposited. The surfaces showed superhydrophobicity after being modified by stearic acid. The maximum contact angle of water was 164.3 degrees with a sliding angle close to zero degree. By controlling deposition conditions, versatile coatings have been produced and the effects of morphology on wettability are discussed. Coating texture has been analyzed by X-ray diffraction. The surfaces showed excellent abrasion resistance and water-repellence
Tetrahedrite-(Ni), Cu6(Cu4Ni2)Sb4S13, the first nickel member of tetrahedrite group mineral from Luobusa chromite deposits, Tibet, China
No full textTetrahedrite-(Ni) (IMA2021-031), ideally Cu-6(Cu4Ni2)Sb4S13, is the first natural Ni-member of tetrahedrite group mineral found in Luobusa chromite deposit, Tibet, China. The new species occurs as anhedral grains 2 to 20 mu m in size, associated with gersdorffite, vaesite, and chalcostibite, which are disseminated in a matrix of dolomite, magnesite, quartz, Cr-rich mica, and Cr-bearing clinochlore. Tetrahedrite-(Ni) is black in color with a reddish-black streak and metallic luster. It is brittle with uneven fractures and has a calculated density of 5.073 gcm(-3). The mean values of 9 electron micro-probe analyses (wt%) are Cu 39.83, Ni 5.67, Fe 1.45, Sb 21.69, As 5.45, S 25.39, total 99.48, and the empirical formula calculated on the basis of cation = 16 apfu is Cu-M(2)(6.00)M(1)[Cu-4.03(Ni1.55Fe0.42)(Sigma 1.97)](Sigma 6.00)(X(3))(Sb2.85As1.16)(Sigma 4.01)S-12.67. Tetrahedrite-(Ni) is cubic, with space group I43m, a = 10.3478(4) & Aring;, V = 1108.00(14) & Aring;(3), and Z = 2. Its crystal structure has been solved by X-ray single-crystal diffraction on the basis of 188 independent reflections, with a final R-1 = 0.0327. Tetrahedrite-(Ni) is isostructural with tetrahedrite group minerals. It represents the first natural tetrahedrite-group mineral with a Ni-dominated charge-compensating constituent. Tetrahedrite-(Ni) may be the product of late-serpentinization at moderately high-temperature conditions around 350 degrees C. In this case, tetrahedrite-(Ni) and its mineral paragenesis record an entire geological process of nickel enrichment, migration, activation, precipitation, and alteration from deep mantle to shallow crust
Rifampicin-resistant Mycobacterium leprae in an elderly leprosy patient in the People's Republic of China
No full textMeiwen Yu,1,* Kan Wu,1,* Bing Pei,2 Degang Yang,2 Qiulin Wang,1 Hongsheng Wang,1 Jianping Shen,1 Liangbing Yan,1 Guochen Zhang1 1Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, National Center for STD and Leprosy Control, China CDC, Nanjing, People's Republic of China; 2Department of Infectious Diseases, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China *These authors contributed equally to this work Abstract: The reported number of registered leprosy patients worldwide declined with the introduction of multidrug therapy. However, the emergence of rifampicin resistance in leprosy patients engenders difficulties for an individual patient, and its dissemination could pose a threat to leprosy control. This study reports an elderly patient who was diagnosed with rifampicin-resistant lepromatous leprosy. This case indicates that inadequate treatment and poor compliance may eventually result in rifampicin resistance in Mycobacterium leprae and clinical relapse. Keywords: leprosy, rifampicin, drug resistance, elderly patien
Nomenclature of the ancylite supergroup
No full textThe ancylite supergroup is approved by the IMA-CNMNC, with the general crystal chemical formula (M3+xM2+2-x)(CO3)2[(OH)x·(2–x)H2O] (1 ≤ x ≤ 2, Z = 2). The ancylite supergroup can be divided into two groups defined by different proportions of the M cation and hydroxyl anion and/or water molecule: the ancylite group is defined for 1 ≤ x ≤ 1.5; the kozoite group is defined for 1.5 < x ≤ 2. The ancylite supergroup minerals are orthorhombic with space group Pmcn, or monoclinic with space group Pm11, and have a crystal structure with species-defining trivalent and divalent M cations (M = La3+, Ce3+, Nd3+, Ca2+, Sr2+ and Pb2+) which centre ten-vertex polyhedron formed by oxygen atoms at three independent O sites. At the vertices of triangular (CO3)2- anion, two are oxygen atoms, while the third one, O(3), is statistically filled with (OH)- groups and H2O molecules. The triangular faces of three oxygen atoms of MO10 coordination polyhedra join the chains of this ten-vertex polyhedral, which is extended along the c axis. (CO3) triangles connect chains in three dimensions. Up to now, eight valid mineral species with M2+ = Sr2+, Ca2+ and Pb2+ belong to the ancylite group [ancylite-(La), ancylite-(Ce), calcioancylite-(La), calcioancylite-(Ce), calcioancylite-(Nd), gysinite-(La), gysinite-(Ce), and gysinite-(Nd)]. Two hydroxyl carbonates with only rare earth elements as species-defining cations, kozoite-(La) and kozoite-(Nd) are members of the kozoite group
ESUR: A SYSTEM FOR EVENTS DETECTION IN SURVEILLANCE VIDEO
No full textIn this paper, we present our eSur (Event detection system on SURveillance video) system, which is derived from TRECVID'09 surveillance tasks. Currently, eSur attempts to detect two categories of events: 1) single-actor events (i.e., PersonRuns and ElevatorNoEntry) irrespective of any interaction between individuals, and 2) pair-activity events (i. e., PeopleMeet, PeopleSplitUp, and Embrace) involves more than one individual. eSur consists of three major stages, i. e., preprocessing, event classification, and post-processing. The preprocessing involves view classification, background subtraction, head-shoulder detection, human body detection and object tracking. Event classification fuses One-vs.-All SVM and rule-based classifiers to identify single-actor and pair-activity events in an ensemble way. To reduce false alarms, we introduce prior knowledge into the post-processing, and in particular, we apply a so-called event merging process over TRECVID dataset. Extensive experiments have been performed over TRECVid'08 and '09 ED data corpus involving in total 144 hours surveillance video of London Gatwick airport. According to the TRECVid-ED formal evaluation, our prototype has yielded fairly promising results over TRECVid'09 dataset, with top Act. DCR of 1.023, 1.025, 1.02, and 0.334 for PeopleMeet, PeopleSplitUp, Embrace, and ElevatorNoEntry, respectively.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000287728002101&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicImaging Science & Photographic TechnologyEICPCI-S(ISTP)
Engineered manganese redox cycling for utilisation of biogenic manganese oxides to remove micropollutants
No full textHuman activities such as agriculture, industry and domestic practices would generate various pollutants in wastewater, resulting in an increasing public concern about contamination in the aquatic environment. Micropollutants, consist of pharmaceuticals, pesticides, personal care products and many other organic compounds. These micropollutants are commonly presented in wastewaters at trace-level concentrations (ng/L-μg/L). However, conventional primary and secondary wastewater treatment processes do not remove micropollutants effectively. Thus, many micropollutants still existed in the effluents of typical wastewater treatment plants (WWTPs), becoming a potential risk to wildlife and even human beings. Recently, BioMnOx-based processes have been accepted as an efficient and promising treatment technology for the removal of micropollutants in municipal wastewater, by combining chemical oxidation with biodegradation. However, to date, few studies have focused on the practical applications of BioMnOx-based technology in a continuous wastewater treatment system for polishing such wastewater. Therefore, the main purpose of this PhD project is devoted to realistically applying BioMnOx-based technology during wastewater treatment by: ⅰ) developing a BioMnOx-based biofilm system for continuous wastewater treatment, and additionally investigating micropollutant removal performance in municipal wastewater, ⅱ) utilising BioMnOx to activate peroxymonosulfate (PMS), in order to generate radical oxygen species (ROS) for in situ chemical oxidation, thus efficiently removing micropollutants in municipal wastewater.First, a laboratory-scale BioMnOx-based biofilm reactor (BioMn-MBBR) was constructed. During continuous operation, MnOB was enriched in the suspended biofilms within the first 20 days, and then producing BioMnOx in the suspended biofilms. A specific manganese-oxidising bacteria belonging to Stenotrophomonas sp. was isolated from the suspended biofilms. To investigate the feasibility of this combined reactor for micropollutant removal, spiking experiments with 14 selected micropollutants were conducted in both synthetic sewage and real municipal wastewater. It was observed that the removal of specific micropollutants, such as diclofenac (36% vs. 5%) and sulfamethoxazole (80% vs. 24%), was enhanced with BioMn-MBBR in comparison to the control MBBR.Second, to overcome the main shortcoming in the BioMn-MBBR (the additional Mn(II) requirement for BioMnOx production), engineered manganese redox cycling was proposed in a two-stage anaerobic-aerobic MBBR (staged MBBR), aiming to replenish BioMnOx for continuous micropollutant removal in wastewater. For this staged MBBR, MnO2 was added into the anaerobic reactor and then reduced to Mn2+ through microbially-mediated manganese reduction. This reduced Mn2+ was further converted into BioMnOx through microbially-mediated manganese oxidation in the aerobic reactor. Part of the BioMnOx was designed to return to the anaerobic reactor as an alternative to MnO2. According to the mass balance calculation, manganese redox cycling functioned well, and BioMnOx was continuously regenerated in the aerobic reactor. Furthermore, high-throughput sequencing analysis (Illumina platform) revealed a significant microbial community shift in the staged MBBR during manganese redox cycling. Regarding micropollutant removal performance, the results obtained from the batch and continuous-flow experiments showed that the majority of micropollutants, including diclofenac and sulfamethoxazole, were removed (over 80%) through staged MBBR coupled with manganese redox cycling.Third, since several refractory micropollutants still remained in the staged MBBR effluent, a BioMnOx/PMS system was further used to polish this wastewater. In the feasibility test, relatively high removal efficiencies (>80%) for all selected micropollutants were obtained for a short reaction time (20 min), especially for several refractory micropollutants such as carbamazepine (98%), diclofenac (100%) and metoprolol (81%). The effects of inorganic ions and quenching experiments on micropollutant removal were investigated. Subsequently, a polishing BioMnOx/PMS system was constructed by utilising the in situ-generated BioMnOx from our previous aerobic reactor as a catalyst. This BioMnOx/PMS system was then assessed with both synthetic sewage and staged MBRR effluent. The results indicated that the refractory micropollutants carbamazepine, metoprolol and venlafaxine were significantly removed through the BioMnOx/PMS system. Lastly, the treated effluent exhibited minimum toxic effects when using Vibrio fisheri as an indicator.In summary, the overall results demonstrated BioMnOx-based technology, including BioMn-MBBR, engineered manganese redox cycling and BioMnOx/PMS processes, all of which show great promises as cost-effective solutions for treating municipal wastewater containing various micropollutants for future engineered applications
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