861 resultados para Thick coating


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Herein, we report a facile and effective adsorption strategy to improve the performance of Lithium-Sulfur (Li-S) batteries. MnO2 nanosheets grown on the surface of highly conductive graphene resulted in a coupled composite bilayer electrode when coated onto a sulfur cathode. In this way, a high initial specific capacity of 1395 mA h g-1 at a rate of 0.5C, a coulombic efficiency approaching 100% and steady cyclic efficiency with a fade rate of 0.3% per cycle from 10 to 100 cycles has been achieved. This hybrid electrode not only shows enhanced electrochemical performance but can also be easily controlled and scaled thereby aiding future commercialization of high-performance Li-S batteries.

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SIMP steel was newly developed as a candidate structural material for the accelerator driven subcritical system. The serious decarburization of SIMP steel because of the high Si content was used to successfully form a self-growing TiC coating on the surface, after the Ti deposition as a first step. This TiC layer can effectively protect the surface from the static liquid lead-bismuth eutectic (LBE) corrosion at 600 °C up to 2000 h in the low oxygen LBE. However, in the oxygen saturated LBE, the TiC coating is oxidized into porous TiO2 after only 500 h and fails to protect. Therefore, the self-growing TiC coating is desired only when the oxygen content of LBE is strictly controlled on a low level.

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Lanthanum phosphate is one among the lanthanide family of “Rare Earths” following the periodic table of elements. Known under the generic name, Monazite, the rare earth phosphates have melting points above 1900 °C, high thermal phase stability, low thermal conductivity and thermal expansion coefficient similar to some of the high temperature oxides like alumina and zirconia.

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The main objective of this work is the development of a hardmetal components (WC-6%Co) recovery method by thermal deposition process. The thermal deposition technique used was HVOF (high velocity oxygen-fuel). The HVOF enables depositions of thick coatings (100-500 µm) with low porosity levels, high hardness and excellent adhesion. Before deposition, hardmetal samples with different geometries (plates and cylinders) were finished in order to have different roughness. The influence of these parameters in adhesion was studied. After this step, different re-sintering temperatures were used, in order to determine which one allows to obtain the maxima densification, elements distribution and metallurgical bonding. The re-sintering promotes the densification of the coating, with an increase of its hardness and metallurgical bonding formation. The inclusion of an intermetallic layer was tested along with different layer parameters. In liquid phase sintering (1383 and 1455 ºC) a complete densification of the coating occurred, while a bonding between the substrate and the coating only partially happened. The results of SEM/EDS show low levels of porosity and a complete and uniform distribution of the elements of the alloy. The cylindrical samples without intermetallic layer showed the lowest level of porosity and best metallurgical bonding. When the substrate surface was polished (Ra = 0.05 mm) lower levels of porosity and greater metallurgical bonding were found for both geometries. Taking into account the results obtained in this study, we can conclude that the implementation of this process is appropriate for cylindrical components with a polished surface. In these components the intermetallic layer is unnecessary and punctual defects like pores can be repaired with this process.

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Interest in bioaerosol exposure has increased significantly because it is now recognized that exposure to fungal agents is associated with a wide range of adverse health effects with a major impact on public health. Fungi are able to grow on almost all natural and synthetic materials, especially if they are hygroscopic or wet. Aim of the study: Several materials used indoors can contribute to enhance fungal contamination indoors. This study intended to understand the carpet influence on fungal contamination when used in the floor of a hotel room.

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Study developed in order to know the carpet influence when used in the floor of a hotel room. Twelve air samples of 250L (six in a room with carpet and six more in a room with wood floor) were collected through an impaction method with a flow rate of 140 L/min onto malt extract agar (MEA) supplemented with chloramphenicol (0.05%), using the Millipore air Tester (Millipore), during cleaning activities. Outdoor sample was also performed to be used as a reference. Surface samples from floor and desks, taken at the same time, were collected by the swabbing method. to 7 days. Besides fungal contamination, we also assessed particulate matter contamination in both rooms during the same cleaning tasks. In the analyzed sur- faces, isolates belonging to Aspergillus fumigatus complex were the only fungi found in the carpeted room, whereas in the other room we found Penicllium sp. (63.6%) and Aspergillus sp. (13.6%) as the most frequent genera. In the case of particles the room with carpet obtained significant higher values for both metrics (PMC and PNC), showing that carpet may has influence on particles’ contamination of the room.

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The publisher regrets to inform the readers that the image that is appearing for Fig. 8 is incorrect and that the Supplementary material is missing on the published paper. The correct image for Fig. 8 and the Supplementary files are provided below: Fig. 8. (a) Timber blocks covered by invented plastic container bottom open, (b) timber blocks in the field after trial, (c) and (d) comparison between resin-coated blocks without termite damage and control blocks which were severely damaged by termites.

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In this study, the effect of anti-corrosion inhibitor addition to epoxy coating, on the disbanding rate was evaluated. First to determination of mechanism, the bare steel substrates were immersed in the 3.5% NaCl solution and the solution containing 1 mM anti corrosion. The Electrochemical Impedance Spectroscopy was performed after 5 and 24 hour. The results indicated a lower corrosion rate in the presence of inhibitor. During the time, charge transfer resistance, was decreased for the substrates immersed in NaCl solution, and increased for the substrates immersed in NaCl solution containing 1 mM anti corrosion. This result can be related to more stability of corrosion products in presence of anti-corrosion and film formation. The coated substrates, with four different concentration of anticorrosion in coating, were protected under -1.2 voltage in the 3.5% NaCl solution. After 12 and 24 hour, the EIS test and disbanding area measurement, were evaluate. The lower disbanding rate, more charge transfer resistance and less double layer capacitance for the coating containing 0.75w% inhibitor, were observed. The result of Pull-off test after 1 day immersion in 3.5% NaCl solution, showed more wet adhesion for the coating containing 0.75w% inhibitor. The images of FE-SEM electron microscope and surface analyses EDX on the coated substrate after disbanding and the bare substrate immersed in 3.5w% NaCl containing 1 mM inhibitor, were proved the formation of stabilized film.