WorldWideScience

Sample records for control coating performance

  1. Design and Performance of Property Gradient Ternary Nitride Coating Based on Process Control.

    Science.gov (United States)

    Yan, Pei; Chen, Kaijie; Wang, Yubin; Zhou, Han; Peng, Zeyu; Jiao, Li; Wang, Xibin

    2018-05-09

    Surface coating is an effective approach to improve cutting tool performance, and multiple or gradient coating structures have become a common development strategy. However, composition mutations at the interfaces decrease the performance of multi-layered coatings. The key mitigation technique has been to reduce the interface effect at the boundaries. This study proposes a structure design method for property-component gradient coatings based on process control. The method produces coatings with high internal cohesion and high external hardness, which could reduce the composition and performance mutations at the interface. A ZrTiN property gradient ternary nitride coating was deposited on cemented carbide by multi-arc ion plating with separated Ti and Zr targets. The mechanical properties, friction behaviors, and cutting performances were systematically investigated, compared with a single-layer coating. The results indicated that the gradient coating had better friction and wear performance with lower wear rate and higher resistance to peeling off during sliding friction. The gradient coating had better wear and damage resistance in cutting processes, with lower machined surface roughness Ra. Gradient-structured coatings could effectively inhibit micro crack initiation and growth under alternating force and temperature load. This method could be extended to similar ternary nitride coatings.

  2. Mechanical particle coating using polymethacrylate nanoparticle agglomerates for the preparation of controlled release fine particles: The relationship between coating performance and the characteristics of various polymethacrylates.

    Science.gov (United States)

    Kondo, Keita; Kato, Shinsuke; Niwa, Toshiyuki

    2017-10-30

    We aimed to understand the factors controlling mechanical particle coating using polymethacrylate. The relationship between coating performance and the characteristics of polymethacrylate powders was investigated. First, theophylline crystals were treated using a mechanical powder processor to obtain theophylline spheres (grindability of the agglomerates were attributed to differences in particle structure, resulting from consolidation between colloidal particles. High-grindability agglomerates exhibited higher pulverization as their glass transition temperature (T g ) increased and the further pulverization promoted coating. We therefore conclude that the minimization of polymethacrylate powder by pulverization is an important factor in mechanical particle coating using polymethacrylate with low deformability. Meanwhile, when product temperature during coating approaches T g of polymer, polymethacrylate was soften to show high coating performance by plastic deformation. The effective coating by this mechanism may be accomplished by adjusting the temperature in the processor to the T g . Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Optical Coating Performance and Thermal Structure Design for Heat Reflectors of JWST Electronic Control Unit

    Science.gov (United States)

    Quijada, Manuel A.; Threat, Felix; Garrison, Matt; Perrygo, Chuck; Bousquet, Robert; Rashford, Robert

    2008-01-01

    The James Webb Space Telescope (JWST) consists of an infrared-optimized Optical Telescope Element (OTE) that is cooled down to 40 degrees Kelvin. A second adjacent component to the OTE is the Integrated Science Instrument Module, or ISIM. This module includes the electronic compartment, which provides the mounting surfaces and ambient thermally controlled environment for the instrument control electronics. Dissipating the 200 watts generated from the ISIM structure away from the OTE is of paramount importance so that the spacecraft's own heat does not interfere with the infrared light detected from distant cosmic sources. This technical challenge is overcome by a thermal subsystem unit that provides passive cooling to the ISIM control electronics. The proposed design of this thermal radiator consists of a lightweight structure made out of composite materials and low-emittance metal coatings. In this paper, we will present characterizations of the coating emittance, bidirectional reflectance, and mechanical structure design that will affect the performance of this passive cooling system.

  4. Phase Transition Control for High-Performance Blade-Coated Perovskite Solar Cells

    KAUST Repository

    Li, Jianbo

    2018-05-07

    Summary Here, we have identified that the key issue for rational transitioning from spin-coating to blade-coating processes of perovskite films arises from whether intermediate phases participate in the phase transition. In situ characterizations were carried out to provide a comprehensive picture of structural evolution and crystal growth mechanisms. These findings present opportunities for designing an effective process for blade-coating perovskite film: a large-grained dense perovskite film with high crystal quality and photophysical properties can be obtained only via direct crystallization for both spin-coating and blade-coating processes. As a result, the blade-coated MAPbI3 films deliver excellent charge-collection efficiency at both short circuit and open circuit, and photovoltaic properties with efficiencies of 18.74% (0.09 cm2) and 17.06% (1 cm2) in planar solar cells. The significant advances in understanding how the phase transition links spin-coating and blade-coating processes should provide a path toward high-performance printed perovskite devices.

  5. The performance of thermal control coatings on LDEF and implications to future spacecraft

    Science.gov (United States)

    Wilkes, Donald R.; Miller, Edgar R.; Mell, Richard J.; Lemaster, Paul S.; Zwiener, James M.

    1993-01-01

    The stability of thermal control coatings over the lifetime of a satellite or space platform is crucial to the success of the mission. With the increasing size, complexity, and duration of future missions, the stability of these materials becomes even more important. The Long Duration Exposure Facility (LDEF) offered an excellent testbed to study the stability and interaction of thermal control coatings in the low-Earth orbit (LEO) space environment. Several experiments on LDEF exposed thermal control coatings to the space environment. This paper provides an overview of the different materials flown and their stability during the extended LDEF mission. The exposure conditions, exposure environment, and measurements of materials properties (both in-space and postflight) are described. The relevance of the results and the implications to the design and operation of future space vehicles are also discussed.

  6. Thermal performance of a double pane window with a solar control coating for warm climate of Mexico

    International Nuclear Information System (INIS)

    Xamán, J.; Jiménez-Xamán, C.; Álvarez, G.; Zavala-Guillén, I.; Hernández-Pérez, I.; Aguilar, J.O.

    2016-01-01

    Highlights: • Pseudo-transient thermal performance of a double pane window (DPW) was determined. • The DPW was analyzed each 5 s by a period from 8:00 to 18:00 h. • 57,600 computational runs were necessary and the additive correction multigrid was implemented. • Solar control coating (SCC) in a DPW reduces 1073.79 W/m 2 with respect to the DPW without SCC. • SCC is highly recommended in a DPW because it reduces a 53.88% of the amount of energy gained. - Abstract: The pseudo-transient thermal performance (each 5 s) of a double pane window without and with a solar control coating was determined numerically. The study considers warm climatic conditions (Mexico) and a period from 8:00 to 18:00 h. The effect of varying the indoor air temperature (15–30 °C); and the incident solar radiation and the outdoor air temperature as functions of time is analyzed. The simulations were done with a self-developed ForTran program and it was verified with results from the literature. To obtain the results, 57,600 computational runs were necessary. From the results, the double pane window with a solar control coating allows a smaller heat flux to enter into a room than the corresponding without a solar control coating. The solar control coating in double glass window reduces the amount of 1073.79 W h/m 2 with respect to the case without a solar control coating, which represents a reduction of 53.88% of the heat gain.

  7. Performance evaluation of one coat systems for new steel bridges.

    Science.gov (United States)

    2011-06-01

    In an effort to address cost issues associated with shop application of conventional three-coat systems, the Federal : Highway Administration completed a study to investigate the performance of eight one-coat systems and two control : coatings for co...

  8. Phase Transition Control for High-Performance Blade-Coated Perovskite Solar Cells

    KAUST Repository

    Li, Jianbo; Munir, Rahim; Fan, Yuanyuan; Niu, Tianqi; Liu, Yucheng; Zhong, Yufei; Yang, Zhou; Tian, Yuansi; Liu, Bo; Sun, Jie; Smilgies, Detlef-M.; Thoroddsen, Sigurdur T; Amassian, Aram; Zhao, Kui; Liu, Shengzhong (Frank)

    2018-01-01

    with high crystal quality and photophysical properties can be obtained only via direct crystallization for both spin-coating and blade-coating processes. As a result, the blade-coated MAPbI3 films deliver excellent charge-collection efficiency at both short

  9. Seal coat binder performance specifications.

    Science.gov (United States)

    2013-11-01

    Need to improve seal coat binder specs: replace empirical tests (penetration, ductility) with : performance-related tests applicable to both : unmodified and modified binders; consider temperatures that cover entire in service : range that are tied t...

  10. Performance of ceramic coatings on diesel engines

    International Nuclear Information System (INIS)

    MacAdam, S.; Levy, A.

    1986-01-01

    Partially stabilized zirconia ceramic thermal barrier coatings were plasma sprayed on the valve faces and tulips and the piston crowns and cylinder heads of a locomotive size diesel engine at a designated thickness of 375μm (0.015''). They were tested over a range of throttle settings for 500 hours using No. 2 diesel oil fuel. Properly applied coatings performed with no change in composition, morphology or thickness. Improperly applied coatings underwent spalling durability was dependent on quality control of the plasma spray process

  11. UNDERWATER COATINGS FOR CONTAMINATION CONTROL

    International Nuclear Information System (INIS)

    Julia L. Tripp; Kip Archibald; Ann Marie Phillips; Joseph Campbell

    2004-01-01

    The Idaho National Laboratory (INL) deactivated several aging nuclear fuel storage basins. Planners for this effort were greatly concerned that radioactive contamination present on the basin walls could become airborne as the sides of the basins became exposed during deactivation and allowed to dry after water removal. One way to control this airborne contamination was to fix the contamination in place while the pool walls were still submerged. There are many underwater coatings available on the market for marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives were easily applied and adhered well to the substrates (pool wall materials) found in INL fuel pools. Lab-scale experiments were conducted by applying fourteen different commercial underwater coatings to four substrate materials representative of the storage basin construction materials, and evaluating their performance. The coupons included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The evaluation criteria included ease of application, adherence to the four surfaces of interest, no change on water clarity or chemistry, non-hazardous in final applied form and be proven in underwater applications. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected from the underwater coatings tested for application to all four pools. Divers scrubbed loose contamination off the basin walls and floors using a ship hull scrubber and vacuumed up the sludge. The divers then applied the coating using a special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pools with no detectable airborne contamination releases

  12. How PE tape performs under concrete coating

    International Nuclear Information System (INIS)

    Dritt, H.J.

    1984-01-01

    The program objectives were to evaluate the performance of polyethylene tape plant coating and fusion bonded epoxy powder systems with particular respect to the following: 1. Concrete coating application procedures; 2. The shear resistance during laying and retrieving operations of the coating at the various interfaces (a) Pipe and anti-corrosion coating; (b) Anti-corrosion coating and outerwrap; (c) Overlap areas of the anti-corrosion and outerwrap layers; (d) Between concrete and the various corrosion coatings during laying and retrieving operations. 3. Resistance to damage of the coating as a consequence of cracking or slippage of the concrete weight coating. 4. Ability of various coatings to withstand the damage during concrete application by both impact and compression methods; 5. Evaluation of tape and shrink sleeve joint coatings at the cut-back area as well as performance of tape under hot asphalt coating

  13. Controlled Deposition and Performance Optimization of Perovskite Solar Cells Using Ultrasonic Spray-Coating of Photoactive Layers.

    Science.gov (United States)

    Chang, Wei-Chieh; Lan, Ding-Hung; Lee, Kun-Mu; Wang, Xiao-Feng; Liu, Cheng-Liang

    2017-04-10

    This study investigated a new film-deposition technique, ultrasonic spray-coating, for use in the production of a photoactive layer of perovskite solar cells. Stable atomization and facile fabrication of perovskite thin films by ultrasonic spray-coating were achieved in a one-step method through manipulating the ink formulation (e.g., solution concentration, precursor composition, and mixing solvent ratio) and the drying kinetics (e.g., post-annealing temperature). The performance of the perovskite solar cells was mainly influenced by the intrinsic film morphology and crystalline orientation of the deposited perovskite layer. By suitable optimization of the spreading and drying conditions of the ink, ultrasonic spray-coated perovskite photovoltaic devices were obtained with a maximum power conversion efficiency of 11.30 %, a fill factor of 73.6 %, a short-circuit current of 19.7 mA cm -1 , and an open-circuit voltage of 0.78 V, respectively. Notably, the average power efficiency reached above 10 %, attributed to the large flower-like perovskite crystal with orientation along the (1 1 2)/(2 0 0) and (2 2 4)/(4 0 0) directions. Thus, the ultrasonic spray-coating method for perovskite photoactive layers, combining advantages of good photovoltaic performance results and benefits from cost and processing, has the potential for large-scale commercial production. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Corrosion performance of epoxy-coated reinforcement in aggressive environments

    Science.gov (United States)

    Vaca Cortes, Enrique

    The objective of this research was to investigate the integrity and corrosion performance of epoxy-coated reinforcement in aggressive environments. A series of experimental studies were conducted: (a) hot water immersion and knife adhesion testing for assessment of coating adhesion; (b) materials and procedures for repairing coating damage; (c) degree of mechanical damage caused during concrete placement when using metal head and rubber head vibrators; (d) accelerated corrosion of coated bars embedded in macrocell and beam specimens placed in a corrosive environment for more than four years. The effects of coating condition and amount of damage, repaired vs. unrepaired damage, bar fabrication, and concrete cracking were studied. Regardless of coating condition, the performance of epoxy-coated bars was better than that of uncoated bars. Unlike black bars, coated bars did not exhibit deep pitting or substantial loss of cross section at crack locations. Damage to epoxy coating was the most significant factor affecting corrosion performance. Bars with coating in good condition, without any visible damage, performed best. The greater the size and frequency of damage, the more severe and extensive the amount of corrosion. The performance of bars that were fabricated or bent after coating was worse than that of coated straight bars. Mixing coated and uncoated bars in the same concrete member led to undesirable performance. Patching damaged coating reduced but did not prevent corrosion, particularly at bar ends. The most important factor in coating repair was the type and properties of the patching material. Surface preparation prior to coating had little effect. The absence of cracks in the concrete delayed, but did not prevent the onset of corrosion of coated bars. During consolidation of concrete, rubber head vibrators caused less damage to epoxy-coated reinforcement than did comparable metal heads. Hot water and adhesion tests were useful and practical for evaluating

  15. Wear performance of laser processed tantalum coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dittrick, Stanley; Balla, Vamsi Krishna; Bose, Susmita; Bandyopadhyay, Amit, E-mail: amitband@wsu.edu

    2011-12-01

    This first generation investigation evaluates the in vitro tribological performance of laser-processed Ta coatings on Ti for load-bearing implant applications. Linear reciprocating wear tests in simulated body fluid showed one order of magnitude less wear rate, of the order of 10{sup -4} mm{sup 3}(N.m){sup -1}, for Ta coatings compared to Ti. Our results demonstrate that Ta coatings can potentially minimize the early-stage bone-implant interface micro-motion induced wear debris generation due to their excellent bioactivity comparable to that of hydroxyapatite (HA), high wear resistance and toughness compared to popular HA coatings. Highlights: {yields} In vitro wear performance of laser processed Ta coatings on Ti was evaluated. {yields} Wear tests in SBF showed one order of magnitude less wear for Ta coatings than Ti. {yields} Ta coatings can minimize early-stage micro-motion induced wear debris generation.

  16. Lithium Coatings on NSTX Plasma Facing Components and Its Effects On Boundary Control, Core Plasma Performance, and Operation

    Energy Technology Data Exchange (ETDEWEB)

    H.W.Kugel, M.G.Bell, H.Schneider, J.P.Allain, R.E.Bell, R Kaita, J.Kallman, S. Kaye, B.P. LeBlanc, D. Mansfield, R.E. Nygen, R. Maingi, J. Menard, D. Mueller, M. Ono, S. Paul, S.Gerhardt, R.Raman, S.Sabbagh, C.H.Skinner, V.Soukhanovskii, J.Timberlake, L.E.Zakharov, and the NSTX Research Team

    2010-01-25

    NSTX high-power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a Liquid Lithium Divertor surface on the outer part of the lower divertor.

  17. Lithium coatings on NSTX plasma facing components and its effects on boundary control, core plasma performance, and operation

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, H.W., E-mail: hkugel@pppl.gov [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States); Bell, M.G.; Schneider, H. [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States); Allain, J.P. [Purdue University, School of Nuclear Engineering, West Lafayette, IN 47907 (United States); Bell, R.E.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.P.; Mansfield, D. [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States); Nygren, R.E. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Maingi, R. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Menard, J.; Mueller, D.; Ono, M.; Paul, S.; Gerhardt, S. [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States); Raman, R. [University of Washington, Seattle, WA 98195 (United States); Sabbagh, S. [Columbia University, New York, NY 10027 (United States); Skinner, C.H. [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States)

    2010-11-15

    NSTX high power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following the wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a liquid lithium divertor surface on the outer part of the lower divertor.

  18. Lithium Coatings on NSTX Plasma Facing Components and Its Effects On Boundary Control, Core Plasma Performance, and Operation

    International Nuclear Information System (INIS)

    Kugel, H.W.; Bell, M.G.; Schneider, H.; Allain, J.P.; Bell, R.E.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.P.; Mansfield, D.; Nygen, R.E.; Maingi, R.; Menard, J.; Mueller, D.; Ono, M.; Paul, S.; Gerhardt, S.; Raman, R.; Sabbagh, S.; Skinner, C.H.; Soukhanovskii, V.; Timberlake, J.; Zakharov, L.E.; NSTX Research Team

    2010-01-01

    NSTX high-power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a Liquid Lithium Divertor surface on the outer part of the lower divertor.

  19. Instrumental color control for metallic coatings

    Science.gov (United States)

    Chou, W.; Han, Bing; Cui, Guihua; Rigg, Bryan; Luo, Ming R.

    2002-06-01

    This paper describes work investigating a suitable color quality control method for metallic coatings. A set of psychological experiments was carried out based upon 50 pairs of samples. The results were used to test the performance of various color difference formulae. Different techniques were developed by optimising the weights and/or the lightness parametric factors of colour differences calculated from the four measuring angles. The results show that the new techniques give a significant improvement compared to conventional techniques.

  20. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  1. Simulation to coating weight control for galvanizing

    Science.gov (United States)

    Wang, Junsheng; Yan, Zhang; Wu, Kunkui; Song, Lei

    2013-05-01

    Zinc coating weight control is one of the most critical issues for continuous galvanizing line. The process has the characteristic of variable-time large time delay, nonlinear, multivariable. It can result in seriously coating weight error and non-uniform coating. We develop a control system, which can automatically control the air knives pressure and its position to give a constant and uniform zinc coating, in accordance with customer-order specification through an auto-adaptive empirical model-based feed forward adaptive controller, and two model-free adaptive feedback controllers . The proposed models with controller were applied to continuous galvanizing line (CGL) at Angang Steel Works. By the production results, the precise and stability of the control model reduces over-coating weight and improves coating uniform. The product for this hot dip galvanizing line does not only satisfy the customers' quality requirement but also save the zinc consumption.

  2. Underwater Coatings for Contamination Control

    International Nuclear Information System (INIS)

    Julia L. Tripp; Kip Archibald; Ann-Marie Phillips; Joseph Campbell

    2004-01-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included (1) Test Area North (TAN-607) with epoxy painted concrete walls; (2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; (3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and (4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55 F to 80 F dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: (1) Be easy to apply; (2) Adhere well to the four surfaces of interest; (3) Not change or have a negative impact on water chemistry or clarity; (4) Not be hazardous in final applied form; and (5) Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates

  3. HIGH-PERFORMANCE COATING MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Corrosion, erosion, oxidation, and fouling by scale deposits impose critical issues in selecting the metal components used at geothermal power plants operating at brine temperatures up to 300 C. Replacing these components is very costly and time consuming. Currently, components made of titanium alloy and stainless steel commonly are employed for dealing with these problems. However, another major consideration in using these metals is not only that they are considerably more expensive than carbon steel, but also the susceptibility of corrosion-preventing passive oxide layers that develop on their outermost surface sites to reactions with brine-induced scales, such as silicate, silica, and calcite. Such reactions lead to the formation of strong interfacial bonds between the scales and oxide layers, causing the accumulation of multiple layers of scales, and the impairment of the plant component's function and efficacy; furthermore, a substantial amount of time is entailed in removing them. This cleaning operation essential for reusing the components is one of the factors causing the increase in the plant's maintenance costs. If inexpensive carbon steel components could be coated and lined with cost-effective high-hydrothermal temperature stable, anti-corrosion, -oxidation, and -fouling materials, this would improve the power plant's economic factors by engendering a considerable reduction in capital investment, and a decrease in the costs of operations and maintenance through optimized maintenance schedules.

  4. Tack Coat Performance and Materials Study

    Science.gov (United States)

    2017-06-01

    A good bond provided by a tack coat can improve performance of asphalt overlays. The objectives of this research were: (1) develop a method for testing the bond between pavement layers; (2) evaluate the bond performance and predict long-term performa...

  5. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating

  6. Sequestration Coating Performance Requirements for ...

    Science.gov (United States)

    symposium paper The EPA’s National Homeland Security Research Center (NHSRC), in collaboration with ASTM International, developed performance standards for materials which could be applied to exterior surfaces contaminated by an RDD to mitigate the spread and migration of radioactive contamination.

  7. Laboratory electron exposure of TSS-1 thermal control coating

    Science.gov (United States)

    Vaughn, J. A.; Mccollum, M.; Carruth, M. R., Jr.

    1995-01-01

    RM400, a conductive thermal control coating, was developed for use on the exterior shell of the tethered satellite. Testing was performed by the Engineering Physics Division to quantify effects of the space environment on this coating and its conductive and optical properties. Included in this testing was exposure of RM400 to electrons with energies ranging from 0.1 to 1 keV, to simulate electrons accelerated from the ambient space plasma when the tethered satellite is fully deployed. During this testing, the coating was found to luminesce, and a prolonged exposure of the coating to high-energy electrons caused the coating to darken. This report describes the tests done to quantify the degradation of the thermal control properties caused by electron exposure and to measure the luminescence as a function of electron energy and current density to the satellite.

  8. Performance of multilayer coated silicon pore optics

    Science.gov (United States)

    Ackermann, M. D.; Collon, M. J.; Jensen, C. P.; Christensen, F. E.; Krumrey, M.; Cibik, L.; Marggraf, S.; Bavdaz, M.; Lumb, D.; Shortt, B.

    2010-07-01

    The requirements for the IXO (International X-ray Observatory) telescope are very challenging in respect of angular resolution and effective area. Within a clear aperture with 1.7 m > R > 0.25 m that is dictated by the spacecraft envelope, the optics technology must be developed to satisfy simultaneously requirements for effective area of 2.5 m2 at 1.25 keV, 0.65 m2 at 6 keV and 150 cm2 at 30 keV. The reflectivity of the bare mirror substrate materials does not allow these requirements to be met. As such the IXO baseline design contains a coating layout that varies as a function of mirror radius and in accordance with the variation in grazing incidence angle. The higher energy photon response is enhanced through the use of depth-graded multilayer coatings on the inner radii mirror modules. In this paper we report on the first reflectivity measurements of wedged ribbed silicon pore optics mirror plates coated with a depth graded W/Si multilayer. The measurements demonstrate that the deposition and performance of the multilayer coatings is compatible with the SPO production process.

  9. Robotic weld overlay coatings for erosion control

    Science.gov (United States)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  10. Development of a Laboratory Test Procedure to Evaluate Tack Coat Performance

    OpenAIRE

    YILDIRIM, Yetkin; SMIT, André de Fortier; KORKMAZ, Armagan

    2014-01-01

    A laboratory testing procedure is presented, the results of which may be used for determining the best combination of tack coat type, mixture type, and application rate to be applied in the field for optimum performance. Tack coat related performance results were determined from Hamburg wheel tracking and simple shear tests on laboratory prepared specimens. This study was undertaken to evaluate the shear strength performance of tack coats under laboratory-controlled conditions. The ...

  11. Tribological performance of Zinc soft metal coatings in solid lubrication

    Science.gov (United States)

    Regalla, Srinivasa Prakash; Krishnan Anirudh, V.; Reddy Narala, Suresh Kumar

    2018-04-01

    Solid lubrication by soft coatings is an important technique for superior tribological performance in machine contacts involving high pressures. Coating with soft materials ensures that the subsurface machine component wear decreases, ensuring longer life. Several soft metal coatings have been studied but zinc coatings have not been studied much. This paper essentially deals with the soft coating by zinc through electroplating on hard surfaces, which are subsequently tested in sliding experiments for tribological performance. The hardness and film thickness values have been found out, the coefficient of friction of the zinc coating has been tested using a pin on disc wear testing machine and the results of the same have been presented.

  12. Performance evaluation of seal coat materials and designs.

    Science.gov (United States)

    2011-01-01

    "This project presents an evaluation of seal coat materials and design method. The primary objectives of this research are 1) to evaluate seal coat performance : from various combinations of aggregates and emulsions in terms of aggregate loss; 2) to ...

  13. Effect of lithium PFC coatings on NSTX density control

    International Nuclear Information System (INIS)

    Kugel, H.W.; Bell, M.G.; Bell, R.; Bush, C.; Gates, D.; Gray, T.; Kaita, R.; Leblanc, B.; Maingi, R.; Majeski, R.; Mansfield, D.; Mueller, D.; Paul, S.; Raman, R.; Roquemore, A.L.; Sabbagh, S.; Skinner, C.H.; Soukhanovskii, V.; Stevenson, T.; Zakharov, L.

    2007-01-01

    Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null ohmic helium discharges were used to coat graphite surfaces that had been pre-conditioned with ohmic helium discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas, respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating

  14. Launch Pad Coatings for Smart Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Bucherl, Cori N.; Li, Wenyan; Buhrow, Jerry W.; Curran, Jerome P.; Whitten, Mary C.

    2010-01-01

    Corrosion is the degradation of a material as a result of its interaction with the environment. The environment at the KSC launch pads has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the US. The 70 tons of highly corrosive hydrochloric acid that are generated by the solid rocket boosters during a launch exacerbate the corrosiveness of the environment at the pads. Numerous failures at the pads are caused by the pitting of stainless steels, rebar corrosion, and the degradation of concrete. Corrosion control of launch pad structures relies on the use of coatings selected from the qualified products list (QPL) of the NASA Standard 5008A for Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment. This standard was developed to establish uniform engineering practices and methods and to ensure the inclusion of essential criteria in the coating of ground support equipment (GSE) and facilities used by or for NASA. This standard is applicable to GSE and facilities that support space vehicle or payload programs or projects and to critical facilities at all NASA locations worldwide. Environmental regulation changes have dramatically reduced the production, handling, use, and availability of conventional protective coatings for application to KSC launch structures and ground support equipment. Current attrition rate of qualified KSC coatings will drastically limit the number of commercial off the shelf (COTS) products available for the Constellation Program (CxP) ground operations (GO). CxP GO identified corrosion detection and control technologies as a critical, initial capability technology need for ground processing of Ares I and Ares V to meet Constellation Architecture Requirements Document (CARD) CxP 70000 operability requirements for reduced ground processing complexity, streamlined integrated testing, and operations phase affordability

  15. Final Technical Report - Recovery Act: Organic Coatings as Encapsulants for Low Cost, High Performance PV Modules

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Hellring; Jiping Shao; James Poole

    2011-12-05

    The objective of this project was to evaluate the feasibility of utilizing PPG's commercial organic coatings systems as efficient, modernized encapsulants for low cost, high performance, thin film photovoltaic modules. Our hypothesis was that the combination of an anticorrosive coating with a more traditional barrier topcoat would mitigate many electrochemical processes that are now responsible for the significant portion of photovoltaic (PV) failures, thereby nullifying the extremely high moisture barrier requirements of currently used encapsulation technology. Nine commercially available metal primer coatings and six commercially available top coatings were selected for screening. Twenty-one different primer/top coat combinations were evaluated. The primer coatings were shown to be the major contributor to corrosion inhibition, adhesion, and barrier properties. Two primer coatings and one top coating were downselected for testing on specially-fabricated test modules. The coated test modules passed initial current leakage and insulation testing. Damp Heat testing of control modules showed visible corrosion to the bus bar metal, whereas the coated modules showed none. One of the primer/top coat combinations retained solar power performance after Damp Heat testing despite showing some delamination at the EVA/solar cell interface. Thermal Cycling and Humidity Freeze testing resulted in only one test module retaining its power performance. Failure modes depended on the particular primer/top coating combination used. Overall, this study demonstrated that a relatively thin primer/top coating has the potential to replace the potting film and backsheet in crystalline silicon-based photovoltaic modules. Positive signals were received from commercially available coatings developed for applications having performance requirements different from those required for photovoltaic modules. It is likely that future work to redesign and customize these coatings would result in

  16. Physically vapor deposited coatings on tools: performance and wear phenomena

    International Nuclear Information System (INIS)

    Koenig, W.; Fritsch, R.; Kammermeier, D.

    1991-01-01

    Coatings produced by physical vapor deposition (PVD) enhance the performance of tools for a broad variety of production processes. In addition to TiN, nowadays (Ti,Al)N and Ti(C,N) coated tools are available. This gives the opportunity to compare the performance of different coatings under identical machining conditions and to evaluate causes and phenomena of wear. TiN, (Ti,Al)N and Ti(C,N) coatings on high speed steel (HSS) show different performances in milling and turning of heat treated steel. The thermal and frictional properties of the coating materials affect the structure, the thickness and the flow of the chips, the contact area on the rake face and the tool life. Model tests show the influence of internal cooling and the thermal conductivity of coated HSS inserts. TiN and (Ti,Zr)N PVD coatings on cemented carbides were examined in interrupted turning and in milling of heat treated steel. Experimental results show a significant influence of typical time-temperature cycles of PVD and chemical vapor deposition (CVD) coating processes on the physical data and on the performance of the substrates. PVD coatings increase tool life, especially towards lower cutting speeds into ranges which cannot be applied with CVD coatings. The reason for this is the superior toughness of the PVD coated carbide. The combination of tough, micrograin carbide and PVD coating even enables broaching of case hardened sliding gears at a cutting speed of 66 m min -1 . (orig.)

  17. Estimation of long-term drag performance of fouling control coatings using an ocean-placed raft with multiple dynamic rotors

    DEFF Research Database (Denmark)

    Lindholdt, Asger; Dam-Johansen, Kim; Yebra, D. M.

    2015-01-01

    An experimental setup was designed and built to estimate changes in the skin friction of fouling control coatings (FCC) over an extended period of time in conditions simulating the vast majority of ship profiles (regarding speed and activity) in the present market. The setup consisted of two sepa...... within the range of experimental uncertainty. The average surface roughness of the FCCs in the newly applied and mechanically cleaned condition, determined as the Rt(50) and R z parameters, was evaluated as poor predictors of skin friction....

  18. 49 CFR 192.461 - External corrosion control: Protective coating.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Protective coating... for Corrosion Control § 192.461 External corrosion control: Protective coating. (a) Each external protective coating, whether conductive or insulating, applied for the purpose of external corrosion control...

  19. The mechanical integrity and protective performance of silica coatings

    International Nuclear Information System (INIS)

    Crouch, A.G.; Dooley, R.B.

    1976-01-01

    Silica coatings have been developed to reduce the oxidation rates of 9Cr and other steels in high temperature environments. An important aspect of their performance is their ability to withstand the mechanical and thermal strains likely to be encountered in practical applications. This has been examined. Silica-coated 9 Cr steel specimens were deformed in tension and coating failure was detected by scanning electron microscope observations of the oxide stringers which delineated the strain-induced cracks on subsequent exidation. Coating fracture was shown to occur in the strain range 0.27 to 0.45%. The crack separation at constant coating thickness decresed with strain and at constant strain was approximately proportional to the square root of the coating thickness. The implications of these results for the protection of the underlying alloy by a cracked coating are considered. (author)

  20. Radiation cured coatings for high performance products

    International Nuclear Information System (INIS)

    Parkins, J.C.; Teesdale, D.H.

    1984-01-01

    Development over the past ten years of radiation curable coating and lacquer systems and the means of curing them has led to new products in the packaging, flooring, furniture and other industries. Solventless lacquer systems formulated with acrylates and other resins enable high levels of durability, scuff resistance and gloss to be achieved. Ultra violet and electron beam radiation curing are used, the choice depending on the nature of the coating, the product and the scale of the operation. (author)

  1. Electrically conductive, black thermal control coatings for spacecraft applications. III - Plasma-deposited ceramic matrix

    Science.gov (United States)

    Hribar, V. F.; Bauer, J. L.; O'Donnell, T. P.

    1987-01-01

    Five black, electrically-conductive thermal control coatings have been formulated and tested for application on the Galileo spacecraft. The coatings consist of both organic and inorganic systems applied on titanium, aluminum, and glass/epoxy composite surfaces. The coatings were tested under simulated space environment conditions. Coated specimens were subjected to thermal radiation, convective and combustive heating, and cryogenic conditions over a temperature range between -196 C and 538 C. Mechanical, physical, thermal, electrical, and thermooptical properties are presented for one of these coatings. This paper describes the preparation, characteristics, and spraying of iron titanate on titanium and aluminum, and presents performance results.

  2. Wear and corrosion performance of metallurgical coatings in sodium

    International Nuclear Information System (INIS)

    Johnson, R.N.; Farwick, D.G.

    1980-01-01

    The friction, wear, and corrosion performance of several metallurgical coatings in 200 to 650 0 C sodium are reviewed. Emphasis is placed on those coatings which have successfully passed the qualification tests necessary for acceptance in breeder reactor environments. Tests include friction, wear, corrosion, thermal cycling, self-welding, and irradiation exposure under as-prototypic-as-possible service conditions. Materials tested were coatings of various refractory metal carbides in metallic binders, nickel-base and cobalt-base alloys and intermetallic compounds such as the aluminides and borides. Coating processes evaluated included plasma spray, detonation gun, sputtering, spark-deposition, and solid-state diffusion

  3. Coating effect of chitosan irradiation on performance of strawberries (Fragaria x ananassa Duchesne)

    International Nuclear Information System (INIS)

    Gatot Trimulyadi Rekso; Adjat Sudradjat

    2016-01-01

    Strawberry is a horticultural product which has high economic value, however, strawberries are easily damaged. Therefore, required proper post harvest handling for keep up the appearances of strawberries, one of them is the edible coating technique using chitosan. The purpose of this research was to maintaining the appearance of strawberry. Chitosan is irradiated at a dose of 0 kGy, 5 kGy, and 10 kGy, and then characterized. Observations were carried on for five days at room temperature including: the testing of the performance of the fruit that was observed visually and analysis of fruit weight loss. The results showed that the performance of strawberries is coating with irradiated chitosan of 10 kGy is still good. The percentage of weight loss strawberries coated with irradiated chitosan smaller than the strawberries without coating with chitosan (control). Strawberries coated with irradiated chitosan has a shelf life and weight loss better than control. (author)

  4. Microencapsulation of Self Healing Agents for Corrosion Control Coatings

    Science.gov (United States)

    Jolley, S. T.; Li, W.; Buhrow, J. W.; Calle, L. M.

    2011-01-01

    Corrosion, the environmentally induced degradation of materials, is a very costly problem that has a major impact on the global economy. Results from a 2-year breakthrough study released in 2002 by the U.S. Federal Highway Administration (FHWA) showed that the total annual estimated direct cost associated with metallic corrosion in nearly every U.S. industry sector was a staggering $276 billion, approximately 3.1% of the nation's Gross Domestic Product (GOP). Corrosion protective coatings are widely used to protect metallic structures from the detrimental effects of corrosion but their effectiveness can be seriously compromised by mechanical damage, such as a scratch, that exposes the metallic substrate. The incorporation of a self healing mechanism into a corrosion control coating would have the potential to significantly increase its effectiveness and useful lifetime. This paper describes work performed to incorporate a number of microcapsule-based self healing systems into corrosion control coatings. The work includes the preparation and evaluation of self-healing systems based on curable epoxy, acrylate, and siloxane resins, as well as, microencapsulated systems based on passive, solvent born, healing agent delivery. The synthesis and optimization of microcapsule-based self healing systems for thin coating (less than 100 micron) will be presented.

  5. Surface Coating of Plastic Parts for Business Machines (Industrial Surface Coating): New Source Performance Standards (NSPS)

    Science.gov (United States)

    Learn more about the new source performance standards (NSPS) for surface coating of plastic parts for business machines by reading the rule summary and history and finding the code of federal regulations as well as related rules.

  6. Corrosion performance of inorganic coatings in seawater

    NARCIS (Netherlands)

    Zhang, X.; Buter, S.J.; Ferrari, G.M.; Westing, E. van; Kowalski, L.

    2011-01-01

    Inorganic coatings are widely used to protect carbon steel hydraulic cylinder rods from wear and corrosion in aggressive offshore environment. Different types of lay-ers such as Ni/Cr, Al2O3, Cr2O3, TiO2, and Inconel 625 layers were applied to the carbon steels by plasma, High Velocity Oxygen Fuel

  7. Performance comparison of various seal coat grades used in Texas.

    Science.gov (United States)

    2012-07-01

    This report documents research efforts to provide comparative quantitative performance information for various grades of seal coat aggregate available in the Texas Department of Transportations standard specifications. Length of service before rep...

  8. Studies on black anodic coatings for spacecraft thermal control applications

    Energy Technology Data Exchange (ETDEWEB)

    Uma Rani, R.; Subba Rao, Y.; Sharma, A.K. [ISRO Satellite Centre, Bangalore (India). Thermal Systems Group

    2011-10-15

    An inorganic black colouring process using nickel sulphate and sodium sulphide was investigated on anodized aluminium alloy 6061 to provide a flat absorber black coating for spacecraft thermal control applications. Influence of colouring process parameters (concentration, pH) on the physico-optical properties of black anodic film was investigated. The nature of black anodic film was evaluated by the measurement of film thickness, micro hardness and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy studies confirmed the presence of nickel and sulphur in the black anodic coating. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion resistance of the coating. The environmental tests, namely, humidity, corrosion resistance, thermal cycling and thermo vacuum performance tests were used to evaluate the space worthiness of the coating. Optical properties of the film were measured before and after each environmental test to ascertain its stability in harsh space environment. The black anodic films provide higher thermal emittance ({proportional_to} 0.90) and solar absorptance ({proportional_to} 0.96) and their high stability during the environmental tests indicated their suitability for space and allied applications. (orig.)

  9. Performance improvement by alumina coatings on Y

    NARCIS (Netherlands)

    Zhou, Z.; Zhou, Nan; Lu, Xiangyang; ten Kate, O.M.; Valdesueiro Gonzalez, D.; van Ommen, J.R.; Hintzen, H.T.J.M.

    2016-01-01

    To improve the thermal stability, Al2O3 has been successfully coated on a Y3Al5O12:Ce3+ (YAG:Ce) phosphor powder host by using the Atomic Layer Deposition (ALD) approach in a fluidized bed reactor. Transmission Electron Microscopy

  10. Performance of multilayer coated silicon pore optics

    DEFF Research Database (Denmark)

    Ackermann, M. D.; Collon, M. J.; Cooper-Jensen, Carsten P.

    2010-01-01

    simultaneously requirements for effective area of 2.5 m2 at 1.25 keV, 0.65 m2 at 6 keV and 150 cm2 at 30 keV. The reflectivity of the bare mirror substrate materials does not allow these requirements to be met. As such the IXO baseline design contains a coating layout that varies as a function of mirror radius...

  11. Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

    KAUST Repository

    Bucs, Szilard

    2017-05-30

    Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

  12. Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

    KAUST Repository

    Bucs, Szilard; Valladares Linares, Rodrigo; Siddiqui, Amber; Matin, Asif; Khan, Zafarullah; van Loosdrecht, Mark C.M.; Yang, Rong; Wang, Minghui; Gleason, Karen K.; Kruithof, Joop C.; Vrouwenvelder, Johannes S.

    2017-01-01

    Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

  13. Fluidization control in the wurster coating process

    Directory of Open Access Journals (Sweden)

    el Mafadi Samira

    2003-01-01

    Full Text Available Paniculate coating process in a fluidized bed involves different sub processes including particle wetting, spreading and also consolidation or drying of the coating applied. These sub processes are done simultaneously to particle fluidization and motion. All the parameters of fluidization are known to affect the coating quality. That is why the motion of particles in the Wurster coating process has been observed and described step by step. These observations have achieved a general understanding of phenomena which take place inside the bed during fluidization and have allowed the development of an easy method for optimizing all the parameters affecting this operation.

  14. Performance of HVOF carbide coatings under erosion/corrosion

    International Nuclear Information System (INIS)

    Simard, S.; Arsenault, B.; Legoux, J.G.; Hawthorne, H.M.

    1999-01-01

    Cermet based materials are known to have an excellent performance under several wear conditions. High velocity oxy-fuel (HVOF) technology allows the deposition of such hard materials in the form of protective coatings onto different surfaces. Under slurry erosion, the performance of the coatings is influenced by the occurrence of corrosion reactions on the metallic matrix. Indeed, wet conditions promote the dissolution of metallic binder resulting in a potential synergic effect between the corrosion and wear mechanisms. The composition of the metallic matrix plays a key role on the stability of the coatings and their degradation rate. In this work, four coatings based on tungsten carbide embedded in different metallic binders were evaluated with regard to corrosion and wear. (author)

  15. How to improve the performance of UV cured wood coatings?

    International Nuclear Information System (INIS)

    Mariane Poitoux

    2007-01-01

    Adhesion, scratch and wear resistance are key properties for industrial wood coatings, both for furniture and parquet flooring. Different techniques can be used to evaluate the performances of a coating and results can be strongly affected only by changing the measuring tool used. This paper will explain the different methods available to assess the adhesion, the scratch and wear resistance and their relevancy. The role played by the different oligomers and monomers will be shown, as the impact of the photoinitiator package. (Author)

  16. High performance polypyrrole coating for corrosion protection and biocidal applications

    Science.gov (United States)

    Nautiyal, Amit; Qiao, Mingyu; Cook, Jonathan Edwin; Zhang, Xinyu; Huang, Tung-Shi

    2018-01-01

    Polypyrrole (PPy) coating was electrochemically synthesized on carbon steel using sulfonic acids as dopants: p-toluene sulfonic acid (p-TSA), sulfuric acid (SA), (±) camphor sulfonic acid (CSA), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS). The effect of acidic dopants (p-TSA, SA, CSA) on passivation of carbon steel was investigated by linear potentiodynamic and compared with morphology and corrosion protection performance of the coating produced. The types of the dopants used were significantly affecting the protection efficiency of the coating against chloride ion attack on the metal surface. The corrosion performance depends on size and alignment of dopant in the polymer backbone. Both p-TSA and SDBS have extra benzene ring that stack together to form a lamellar sheet like barrier to chloride ions thus making them appropriate dopants for PPy coating in suppressing the corrosion at significant level. Further, adhesion performance was enhanced by adding long chain carboxylic acid (decanoic acid) directly in the monomer solution. In addition, PPy coating doped with SDBS displayed excellent biocidal abilities against Staphylococcus aureus. The polypyrrole coatings on carbon steels with dual function of anti-corrosion and excellent biocidal properties shows great potential application in the industry for anti-corrosion/antimicrobial purposes.

  17. A Review of Tribological Coatings for Control Drive Mechanisms in Space Reactors

    International Nuclear Information System (INIS)

    CJ Larkin; JD Edington; BJ Close

    2006-01-01

    Tribological coatings must provide lubrication for moving components of the control drive mechanism for a space reactor and prevent seizing due to friction or diffusion welding to provide highly reliable and precise control of reflector position over the mission lifetime. Several coatings were evaluated based on tribological performance at elevated temperatures and in ultrahigh vacuum environments. Candidates with proven performance in the anticipated environment are limited primarily to disulfide materials. Irradiation data for these coatings is nonexistent. Compatibility issues between coating materials and structural components may require the use of barrier layers between the solid lubricant and structural components to prevent deleterious interactions. It would be advisable to consider possible lubricant interactions prior to down-selection of structural materials. A battery of tests was proposed to provide the necessary data for eventual solid lubricant/coating selection

  18. Quality control of fireproof coatings for reinforced concrete structures

    Science.gov (United States)

    Gravit, Marina; Dmitriev, Ivan; Ishkov, Alexander

    2017-10-01

    The article analyzes methods of quality inspection of fireproof coatings (work flow, measuring, laboratory, etc.). In modern construction there is a problem of lack of distinct monitoring for the fire protection testing. There is a description of this testing for reinforced concrete structures. The article shows the results of calculation quality control of hatches as an example of fireproof coating for reinforced concrete structures.

  19. Development of Process Analytical Technology (PAT) methods for controlled release pellet coating.

    Science.gov (United States)

    Avalle, P; Pollitt, M J; Bradley, K; Cooper, B; Pearce, G; Djemai, A; Fitzpatrick, S

    2014-07-01

    This work focused on the control of the manufacturing process for a controlled release (CR) pellet product, within a Quality by Design (QbD) framework. The manufacturing process was Wurster coating: firstly layering active pharmaceutical ingredient (API) onto sugar pellet cores and secondly a controlled release (CR) coating. For each of these two steps, development of a Process Analytical Technology (PAT) method is discussed and also a novel application of automated microscopy as the reference method. Ultimately, PAT methods should link to product performance and the two key Critical Quality Attributes (CQAs) for this CR product are assay and release rate, linked to the API and CR coating steps respectively. In this work, the link between near infra-red (NIR) spectra and those attributes was explored by chemometrics over the course of the coating process in a pilot scale industrial environment. Correlations were built between the NIR spectra and coating weight (for API amount), CR coating thickness and dissolution performance. These correlations allow the coating process to be monitored at-line and so better control of the product performance in line with QbD requirements. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Modeling the performance of coated LPG tanks engulfed in fires

    Energy Technology Data Exchange (ETDEWEB)

    Landucci, Gabriele [CONPRICI - Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali, Universita di Pisa, via Diotisalvi n.2, 56126 Pisa (Italy); Molag, Menso [Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, Princetonlaan 6, 3584 CB Utrecht (Netherlands); Cozzani, Valerio, E-mail: valerio.cozzani@unibo.it [CONPRICI - Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Alma Mater Studiorum - Universita di Bologna, Via Terracini 28 - 40131 Bologna (Italy)

    2009-12-15

    The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in fire engulfment scenarios. The model was validated by experimental results. A specific analysis of the performance of four different reference coating materials was then carried out, also defining specific key performance indicators (KPIs) to assess design safety margins in near-miss simulations. The results confirmed the wide influence of coating application on the expected vessel time to failure due to fire engulfment. A quite different performance of the alternative coating materials was evidenced. General correlations were developed among the vessel time to failure and the effective coating thickness in full engulfment scenarios, providing a preliminary assessment of the coating thickness required to prevent tank rupture for a given time lapse. The KPIs defined allowed the assessment of the available safety margins in the reference scenarios analyzed and of the robustness of thermal protection design.

  1. Modeling the performance of coated LPG tanks engulfed in fires

    International Nuclear Information System (INIS)

    Landucci, Gabriele; Molag, Menso; Cozzani, Valerio

    2009-01-01

    The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in fire engulfment scenarios. The model was validated by experimental results. A specific analysis of the performance of four different reference coating materials was then carried out, also defining specific key performance indicators (KPIs) to assess design safety margins in near-miss simulations. The results confirmed the wide influence of coating application on the expected vessel time to failure due to fire engulfment. A quite different performance of the alternative coating materials was evidenced. General correlations were developed among the vessel time to failure and the effective coating thickness in full engulfment scenarios, providing a preliminary assessment of the coating thickness required to prevent tank rupture for a given time lapse. The KPIs defined allowed the assessment of the available safety margins in the reference scenarios analyzed and of the robustness of thermal protection design.

  2. Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit

    Science.gov (United States)

    Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

    1991-01-01

    Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

  3. performance calculations of gadolinium oxide and boron nitride coated fuel

    International Nuclear Information System (INIS)

    Tanker, E.; Uslu, I.; Disbudak, H.; Guenduez, G.

    1997-01-01

    A comparative study was performed on the behaviour of natural uranium dioxide-gadolinium oxide mixture fuel and boron nitride coated low enriched fuel in a pressurized water reactor. A fuel element containing one burnable poison fuel pins was modeled with the computer code WIMS, and burn-up dependent critically, fissile isotope inventory and two dimensional power distribution were obtained. Calculations were performed for burnable poison fuels containing 5% and 10% gadolinium oxide and for those coated with 1μ,5μ and 10μ of boron nitride. Boron nitride coating was found superior to gadolinium oxide on account of its smoother criticality curve, lower power peaks and insignificant change in fissile isotope content

  4. Development and Application of Coating Weight Control Technology

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Hyoung [Dongbu Steel, Incheon (Korea, Republic of)

    2010-08-15

    Precise coating weight control is very important issue on quality and minimizing operating costs on continuous galvanizing line. These days, many steel making companies are having a new understanding of cost importance by rise raw material prices and customers requirement for cost reduction. Dongbu steel also meets these situations and decided to develop the technologies. Dongbu Steel developed Integrated coating weight control system jointly with Objective Control Ltd. and installed 2CGL and 4CGL. Several technological functions were developed and realized to achieve true hands-off operation and maximum cost benefit by combining model-based preset and dynamic prediction models. We also installed it on 1 CGL on April, 2008. This paper will present the interface, functions and application result of the integrated coating weight control system including Zn saving and coating weight uniformity.

  5. A high performance ceria based interdiffusion barrier layer prepared by spin-coating

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Joost, Mario; Hjelm, Johan

    2011-01-01

    A multiple spin-coating deposition procedure of Ce0.9Gd0.1O1.95 (CGO) for application in solid oxide fuel cells (SOFCs) was developed. The thin and dense CGO layer can be employed as a barrier layer between yttria stabilised zirconia (YSZ) electrolyte and a (La, Sr)(Co, Fe)O3 based cathode....... The decomposition of the polymer precursor used in the spin-coating process was studied. The depositions were performed on anode supported half cells. By controlling the sintering temperature between each spin-coating process, dense and crack-free CGO films with a thickness of approximately 1 μm were obtained....... The successive steps of dense layer production was investigated by scanning electron microscopy. X-ray diffraction was employed to monitor the crystal structure of the CGO layer sintered at different temperatures. The described spin coated barrier layer was evaluated using an anode supported cell...

  6. Emerging Nanotechnology-based Corrosion Control Coatings

    Science.gov (United States)

    2009-02-01

    Carbon black Calcium carbonate Carbon nanotubes Cerium oxide Dendrimers, hyperbranched and supramolecules Indium... Microcapsule with Bisphenol A epoxy Microcapsule with Ketimine O O O O O O O H O n Selected SEM images of various microcapsules SEM and optical...microscopy images of cross-section of self-healing coating Microcapsule rupture and healing agent release is triggered by: T> Tm

  7. Carbon-coated anatase for water purification - cyclic performance

    International Nuclear Information System (INIS)

    Inagaki, M.; Kojin, F.; Nonaka, M.; Toyoda, M.

    2005-01-01

    It was reported that carbon-coated anatase photo-catalysts were able to be prepared through a simple process and gave various advantages for water purification [1-6]. Carbon coating suppressed the phase transformation from anatase to rutile, resulting in a high crystallinity of anatase phase which was desirable for the decomposition of pollutants in water. A high adsorptivity was given to carbon-coated anatase, because of porous nature of carton layers [7]. In addition, these carbon-coated anatase powders could be fixed on the substrate by using organic binder because carbon layer interrupt the direct contact between photo-catalytic anatase particles and organic binder [1]. In the present work, cyclic performance of carbon-coated anatase was studied for the decomposition of a model pollutant, methylene blue (MB), in water by fixing the photo-catalyst particles on a tape. Carbon-coated anatase photo-catalysts were prepared by heating the powder mixtures of commercially available anatase (ST-01, Ishihara Sngyo Co., Ltd) with poly(vinyl alcohol) (PVA) in different mass ratios at 900 C in N 2 , gas flow. Carbon-coated anatase powders thus prepared were fixed on a scotch tape. Photo-catalytic activity was measured on these tapes by irradiating UV rays on one side of the tape in MB solution with 0.3x10 -5 mol/L concentration. Since carbon-coated anatase had a high adsorptivity for MB, all tapes were saturated their adsorption in a concentrated MB solution in advance. The rate constant k for MB photo-decomposition was determined from the linear relations of logarithm of relative concentration of MB in the solution, ln(c/c 0 ), with irradiation time t. In Fig. 1, changes in ln(c/c 0 ) of MB with irradiation time t were shown on two samples with different carbon contents, 8 and 2 mass%, with cycle number. Good linearity was obtained between ln(c/c 0 ) and t. The values of rate constant k calculated from these linear relations were plotted against carbon content of the

  8. Sedimentary controls on modern sand grain coat formation

    Science.gov (United States)

    Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

    2017-05-01

    Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

  9. Porous, Dexamethasone-loaded polyurethane coatings extend performance window of implantable glucose sensors in vivo.

    Science.gov (United States)

    Vallejo-Heligon, Suzana G; Brown, Nga L; Reichert, William M; Klitzman, Bruce

    2016-01-01

    Continuous glucose sensors offer the promise of tight glycemic control for insulin dependent diabetics; however, utilization of such systems has been hindered by issues of tissue compatibility. Here we report on the in vivo performance of implanted glucose sensors coated with Dexamethasone-loaded (Dex-loaded) porous coatings employed to mediate the tissue-sensor interface. Two animal studies were conducted to (1) characterize the tissue modifying effects of the porous Dex-loaded coatings deployed on sensor surrogate implants and (2) investigate the effects of the same coatings on the in vivo performance of Medtronic MiniMed SOF-SENSOR™ glucose sensors. The tissue response to implants was evaluated by quantifying macrophage infiltration, blood vessel formation, and collagen density around implants. Sensor function was assessed by measuring changes in sensor sensitivity and time lag, calculating the Mean Absolute Relative Difference (MARD) for each sensor treatment, and performing functional glucose challenge test at relevant time points. Implants treated with porous Dex-loaded coatings diminished inflammation and enhanced vascularization of the tissue surrounding the implants. Functional sensors with Dex-loaded porous coatings showed enhanced sensor sensitivity over a 21-day period when compared to controls. Enhanced sensor sensitivity was accompanied with an increase in sensor signal lag and MARD score. These results indicate that Dex-loaded porous coatings were able to elicit an attenuated tissue response, and that such tissue microenvironment could be conducive towards extending the performance window of glucose sensors in vivo. In the present article, a coating to extend the functionality of implantable glucose sensors in vivo was developed. Our study showed that the delivery of an anti-inflammatory agent with the presentation of micro-sized topographical cues from coatings may lead to improved long-term glucose sensor function in vivo. We believe that

  10. Environmentally Friendly Coating Technology for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.; Jolley, Scott T.; Pearman, Benjamin P.; Zhang, Xuejun; Fitzpatrick, Lilliana; Gillis, Mathew; Blanton, Michael; hide

    2016-01-01

    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry.

  11. Solution Coating of Pharmaceutical Nanothin Films and Multilayer Nanocomposites with Controlled Morphology and Polymorphism.

    Science.gov (United States)

    Horstman, Elizabeth M; Kafle, Prapti; Zhang, Fengjiao; Zhang, Yifu; Kenis, Paul J A; Diao, Ying

    2018-03-28

    Nanosizing is rapidly emerging as an alternative approach to enhance solubility and thus the bioavailability of poorly aqueous soluble active pharmaceutical ingredients (APIs). Although numerous techniques have been developed to perform nanosizing of API crystals, precise control and modulation of their size in an energy and material efficient manner remains challenging. In this study, we present meniscus-guided solution coating as a new technique to produce pharmaceutical thin films of nanoscale thickness with controlled morphology. We demonstrate control of aspirin film thickness over more than 2 orders of magnitude, from 30 nm to 1.5 μm. By varying simple process parameters such as the coating speed and the solution concentration, the aspirin film morphology can also be modulated by accessing different coating regimes, namely the evaporation regime and the Landau-Levich regime. Using ellipticine-a poorly water-soluble anticancer drug-as another model compound, we discovered a new polymorph kinetically trapped during solution coating. Furthermore, the polymorphic outcome can be controlled by varying coating conditions. We further performed layer-by-layer coating of multilayer nanocomposites, with alternating thin films of ellipticine and a biocompatible polymer, which demonstrate the potential of additive manufacturing of multidrug-personalized dosage forms using this approach.

  12. Thermal barrier coatings: Coating methods, performance, and heat engine applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning conference proceedings on coating methods, performance evaluations, and applications of thermal barrier coatings as protective coatings for heat engine components against high temperature corrosions and chemical erosions. The developments of thermal barrier coating techniques for high performance and reliable gas turbines, diesel engines, jet engines, and internal combustion engines are presented. Topics include plasma sprayed coating methods, yttria stabilized zirconia coatings, coating life models, coating failure and durability, thermal shock and cycling, and acoustic emission analysis of coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. Thermal barrier coatings: Coating methods, performance, and heat engine applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The bibliography contains citations concerning conference proceedings on coating methods, performance evaluations, and applications of thermal barrier coatings as protective coatings for heat engine components against high temperature corrosions and chemical erosions. The developments of thermal barrier coating techniques for high performance and reliable gas turbines, diesel engines, jet engines, and internal combustion engines are presented. Topics include plasma sprayed coating methods, yttria stabilized zirconia coatings, coating life models, coating failure and durability, thermal shock and cycling, and acoustic emission analysis of coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. Product Control of Waste Products with New Coating Materials

    International Nuclear Information System (INIS)

    Krumbach, H.; Steinmetz, H.J.; Odoj, R.; Wartenberg, W.; Grunau, H.

    2009-01-01

    In Germany, with the shaft KONRAD a repository for low radioactive waste will be available at the earliest in the year 2013. The previously conditioned radioactive waste has to be suitable for a longer-term interim storage. They have to be treated in a way that they are chemically stable and that their integrity is guaranteed for a long time. That is why the waste product or the container is covered/ coated for special waste such as hygroscopic waste or waste that includes aluminium. The Product Control Group for radioactive waste (PKS) has to proof the suitability of the so-treated waste for the repository KONRAD on behalf of the Federal Office for Radiation Protection (BfS). This has to be done before the delivering. In this context the PKS also assesses the suitability of new coating materials for low radioactive waste products or containers and their correct technical application. The characteristics and the technical application of polyurethane coatings as well as the control of the so-coated waste for the disposal in the shaft KONRAD are described in this poster. The Poster shows the development stages of the coating and the filling. There are also shown the boundary conditions and the investigations of the Product Control Group for the use of the new coating material for radioactive waste. (authors)

  15. Evaluation of Glider Coatings Against Biofouling for Improved Flight Performance

    Science.gov (United States)

    2011-08-17

    and used to conduct assays of survivorship with approximately 100 nauplii larvae ofArtemia sp. (brine shrimp ). The larvae were exposed to the...seal (D). These coatings showed higher mortality of brine shrimp as well as 100% mortality of cypris larvae during the settlement assay which...brine shrimp compared to the glass control; however these did not inhibit settlement and were evidently not toxic to the cypris larvae . All other

  16. Improvement in Plasma Performance with Lithium Coatings in NSTX

    International Nuclear Information System (INIS)

    Kaita, R.

    2009-01-01

    Lithium as a plasma-facing material has attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Dramatic effects on plasma performance with lithium-coated plasma-facing components (PFC's) have been demonstrated on many fusion devices, including TFTR, T-11M, and FT-U. Using a liquid-lithium-filled tray as a limiter, the CDX-U device achieved very significant enhancement in the confinement time of ohmically heated plasmas. The recent NSTX experiments reported here have demonstrated, for the first time, significant and recurring benefits of lithium PFC coatings on divertor plasma performance in both L- and H- mode regimes heated by neutral beams.

  17. Influence of thickness and coatings morphology in the antimicrobial performance of zinc oxide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, P. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Sampaio, P. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Azevedo, S. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Vaz, C. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Espinós, J.P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-University of Sevilla, Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Teixeira, V., E-mail: vasco@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Carneiro, J.O., E-mail: carneiro@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal)

    2014-07-01

    In this research work, the production of undoped and silver (Ag) doped zinc oxide (ZnO) thin films for food-packaging applications were developed. The main goal was to determine the influence of coatings morphology and thickness on the antimicrobial performance of the produced samples. The ZnO based thin films were deposited on PET (Polyethylene terephthalate) substrates by means of DC reactive magnetron sputtering. The thin films were characterized by optical spectroscopy, X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The antimicrobial performance of the undoped and Ag-doped ZnO thin films was also evaluated. The results attained have shown that all the deposited zinc oxide and Ag-doped ZnO coatings present columnar morphology with V-shaped columns. The increase of ZnO coatings thickness until 200 nm increases the active surface area of the columns. The thinner samples (50 and 100 nm) present a less pronounced antibacterial activity than the thickest ones (200–600 nm). Regarding Ag-doped ZnO thin films, it was verified that increasing the silver content decreases the growth rate of Escherichia coli and decreases the amount of bacteria cells present at the end of the experiment.

  18. A Multifunctional Smart Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz Marina; Buhrow, Jerry W.; Jolley, Scott T.

    2012-01-01

    Corrosion is a destructive process that often causes failure in metallic components and structures. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to control it. The multi-functionality of the coating is based on micro-encapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of other existing microcapsules designs, the corrosion controlled release function that allows the delivery of corrosion indicators and inhibitors on demand only when and where needed. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection efficacy. This

  19. High performance bio-based thermosets for composites and coatings

    Science.gov (United States)

    Paramarta, Adlina Ambeg

    In the recent decade, there has been increasing interest in using renewable feedstocks as chemical commodities for composites and coatings application. Vegetable oils are promising renewable resources due to their wide availability with affordable cost. In fact, the utilization of vegetable oils to produce composite and coatings products has been around for centuries; linseed oil was widely used for wide variety of paints. However, due to its chemical structure, the application of vegetable oils for high-performance materials is limited; and thus chemical modification is necessary. One of the modification approaches is by substituting the glycerol core in the triglycerides with sucrose to form sucrose esters of vegetable oil fatty acids, in which this resin possesses a higher number of functional group per molecule and a more rigid core. In this research, thermosets of highly functionalized sucrose esters of vegetable oils were developed. Two crosslinking methods of epoxidized surcrose soyate (ESS) resins were explored: direct polymerization with anhydride moieties for composite applications and Michael-addition reaction of acrylated-epoxidized sucrose soyate (AESS) for coatings applications. In the first project, it was shown that the reaction kinetics, thermal and mechanical properties of the materials can be tuned by varying the molar ratio between the epoxide and anhydride, plus the type and amount of catalyst. Furthermore, the toughness properties of the ESS-based thermosets can be improved by changing the type of anhydride crosslinkers and incorporating secondary phase rubbers. Then, in the second system, the epoxy functionality in the ESS was converted into acrylate group, which then crosslinked with amine groups through the Michael-addition reaction to produce coatings systems. The high number of functional groups and the fast reactivity of the crosslinker results in coatings that can be cured at ambient temperature, yet still possess moderately high glass

  20. Enhanced propellant performance via environmentally friendly curable surface coating

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2017-06-01

    Full Text Available Surface coating of granular propellants is widely used in a multiplicity of propellants for small, medium and large caliber ammunition. All small caliber ball propellants exhibit burning progressivity due to application of effective deterrent coatings. Large perforated propellant grains have also begun utilizing plasticizing and impregnated deterrent coatings with the purpose of increasing charge weights for greater energy and velocity for the projectile. The deterrent coating and impregnation process utilizes volatile organic compounds (VOCs and hazardous air pollutants (HAPs which results in propellants that need to be forced air dried which impacts air quality. Propellants undergo temperature fluctuations during their life. Diffusion coefficients vary exponentially with variations in temperature. A small temperature increase can induce a faster migration, even over a short period of time, which can lead to large deviations in the concentration. This large concentration change in the ammunition becomes a safety or performance liability. The presence of both polymeric deterrents and nitroglycerin(NG in the nitrocellulose matrix and organic solvents leads to higher diffusion rates. This results in continued emissions of VOCs and HAPs. Conventional polymers tend to partition within the propellant matrix. In other words, localized mixing can occur between the polymer and underlying propellant. This is due to solvent induced softening of the polymer vehicle over the propellant grain. In effect this creates a path where migration can occur. Since nitrate esters, like NG, are relatively small, it can exude to the surface and create a highly unstable and dangerous situation for the warfighter. Curable polymers do not suffer from this partitioning due to “melting” because no VOC solvents are present. They remain surface coated. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and

  1. High performance coated board inspection system based on commercial components

    CERN Document Server

    Barjaktarovic, M; Radunovic, J

    2007-01-01

    This paper presents a vision system for defect (fault) detection on a coated board developed using three industrial firewire cameras and a PC. Application for image processing and system control was realized with the LabView software package. Software for defect detection is based on a variation of the image segmentation algorithm. Standard steps in image segmentation are modified to match the characteristics of defects. Software optimization was accomplished using SIMD (Single Instruction Multiple Data) technology available in the Intel Pentium 4 processors that provided real time inspection capability. System provides benefits such as: improvement in production process, higher quality of delivered coated board and reduction of waste. This was proven during successful exploitation of the system for more than a year.

  2. Performance Evaluation of Refractory Composite Coatings in Potassium Rich Environment

    Directory of Open Access Journals (Sweden)

    Kristina BRINKIENĖ

    2016-09-01

    Full Text Available A laboratory scale method was used to study the performance of reinforced cement composites in potassium rich environment of biomass combustion. Buckwheat husk (BH was used as potential source of unexploited biomass product applicable as biomass derived fuel. In order to enhance the alkali effect on the properties of the investigated materials, the solution of potassium carbonate (K2CO3 was selected as potassium rich aggressive environment. Two reinforced cement composites as potential repair coatings for restoration of damaged refractory surfaces with different composition of aggregate were used in corrosion tests. Performance of refractory coatings was evaluated by analysing the microstructure of the treated composites as well as mechanical properties. Energy-dispersive X-ray spectroscopy (SEM/EDS and optical microscopy were used to study the microstructure in the corroded region of the refractory coatings. Long term studies in the solution of 1M K2CO3 for 56 months have demonstrated that composite with the additive of fluid cracking catalyst of oil refinery and petrochemical industries is more durable in the potassium rich environment.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.8348

  3. Epoxy coatings for anticorrosion challenges: a link between chemistry and performance?

    Energy Technology Data Exchange (ETDEWEB)

    Sauvant-Moynot, Valerie; Schweitzer, Sylvie; Grenier, Jacky; Duval, Sebastien [Institut Francais du Petrole, 1 et 4 avenue Bois Preau, 92450 Rueil-Malmaison (France)

    2004-07-01

    Epoxy coatings have been used extensively for pipeline protection in the oil and gas industries over the past decades. Thank to their outstanding adhesive properties, epoxy resins are classically used for external coating of offshore pipelines although cathodic protection is applied. They provide corrosion protection while being used as neat coating or as primer layer in a three-layer coating. Protection of internal pipelines devoted to gas transport is another application of epoxy coatings. Whatever the case, the choice of the right epoxy formulation should be adapted to the service conditions, namely exposition medium and temperature, in order to provide efficient and sustainable corrosion protection. Epoxy resins constitute a wide family and classical formulations may not fulfill the requirements of today's challenges: as pipelines are require d to operate in more and more difficult conditions, coatings are expected to function in higher temperature conditions; additionally, practical conditions such as temporary injection of methanol make the environmental exposure of the epoxy coating harsher. Therefore, there is a need of a better knowledge of technical performance and limitations of high temperature epoxy resins. This paper examined the influence of the epoxy network architecture on their protection properties and durability while exposed to distilled / sea water at 110 deg. C and to methanol at room temperature. The objective was to investigate the link between resin chemistry and final performance with respect to anticorrosion applications. Five epoxy resin formulations mixed in stoichiometric proportions were cured and post-cured to infinite extent in order to achieve densely cross-linked networks exhibiting controlled and reproducible architectures. Gravimetric and pressurised differential scanning calorimetry (DSC) measurements were performed to evaluate the plasticization effect of both water and methanol on formulations under study. The related

  4. Coated Porous Si for High Performance On-Chip Supercapacitors

    Science.gov (United States)

    Grigoras, K.; Keskinen, J.; Grönberg, L.; Ahopelto, J.; Prunnila, M.

    2014-11-01

    High performance porous Si based supercapacitor electrodes are demonstrated. High power density and stability is provided by ultra-thin TiN coating of the porous Si matrix. The TiN layer is deposited by atomic layer deposition (ALD), which provides sufficient conformality to reach the bottom of the high aspect ratio pores. Our porous Si supercapacitor devices exhibit almost ideal double layer capacitor characteristic with electrode volumetric capacitance of 7.3 F/cm3. Several orders of magnitude increase in power and energy density is obtained comparing to uncoated porous silicon electrodes. Good stability of devices is confirmed performing several thousands of charge/discharge cycles.

  5. Comparison study of different coatings on degradation performance and cell response of Mg-Sr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shangguan, Yongming [Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Sun, Lina [Jinzhou Medical University, Jinzhou 121000 (China); Wan, Peng, E-mail: pwan@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Tan, Lili [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Chengyue [Jinzhou Medical University, Jinzhou 121000 (China); Fan, Xinmin [Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Qin, Ling [Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2016-12-01

    To solve the problem of rapid degradation for magnesium-based implants, surface modification especially coating method is widely studied and showed the great potential for clinical application. However, as concerned to the further application and medical translation for biodegradable magnesium alloys, there are still lack of data and comparisons among different coatings on their degradation and biological properties. This work studied three commonly used coatings on Mg-Sr alloy, including micro-arc oxidation coating, electrodeposition coating and chemical conversion coating, and compared these coatings for requirements of favorable degradation and biological performances, how each of these coating systems has performed. Finally the mechanism for the discrepancy between these coatings is proposed. The results indicate that the micro-arc oxidation coating on Mg-Sr alloy exhibited the best corrosion resistance and cell response among these coatings, and is proved to be more suitable for the orthopedic application. - Highlights: • The MAO, PED and Sr-P coating were fabricated on Mg-Sr alloy to evaluate the degradation. • The MAO coating showed the greatest degradation performance among these three coatings. • The PED coating exhibited worse corrosion resistance even than Mg-Sr substrate. • The value of cell proliferation and ALP activity were ranked in the following order: MAO > Sr-P > PED.

  6. Comparison study of different coatings on degradation performance and cell response of Mg-Sr alloy

    International Nuclear Information System (INIS)

    Shangguan, Yongming; Sun, Lina; Wan, Peng; Tan, Lili; Wang, Chengyue; Fan, Xinmin; Qin, Ling; Yang, Ke

    2016-01-01

    To solve the problem of rapid degradation for magnesium-based implants, surface modification especially coating method is widely studied and showed the great potential for clinical application. However, as concerned to the further application and medical translation for biodegradable magnesium alloys, there are still lack of data and comparisons among different coatings on their degradation and biological properties. This work studied three commonly used coatings on Mg-Sr alloy, including micro-arc oxidation coating, electrodeposition coating and chemical conversion coating, and compared these coatings for requirements of favorable degradation and biological performances, how each of these coating systems has performed. Finally the mechanism for the discrepancy between these coatings is proposed. The results indicate that the micro-arc oxidation coating on Mg-Sr alloy exhibited the best corrosion resistance and cell response among these coatings, and is proved to be more suitable for the orthopedic application. - Highlights: • The MAO, PED and Sr-P coating were fabricated on Mg-Sr alloy to evaluate the degradation. • The MAO coating showed the greatest degradation performance among these three coatings. • The PED coating exhibited worse corrosion resistance even than Mg-Sr substrate. • The value of cell proliferation and ALP activity were ranked in the following order: MAO > Sr-P > PED.

  7. Low Cost High Performance Nanostructured Spectrally Selective Coating

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sungho [Univ. of California, San Diego, CA (United States)

    2017-04-05

    Sunlight absorbing coating is a key enabling technology to achieve high-temperature high-efficiency concentrating solar power operation. A high-performance solar absorbing material must simultaneously meet all the following three stringent requirements: high thermal efficiency (usually measured by figure of merit), high-temperature durability, and oxidation resistance. The objective of this research is to employ a highly scalable process to fabricate and coat black oxide nanoparticles onto solar absorber surface to achieve ultra-high thermal efficiency. Black oxide nanoparticles have been synthesized using a facile process and coated onto absorber metal surface. The material composition, size distribution and morphology of the nanoparticle are guided by numeric modeling. Optical and thermal properties have been both modeled and measured. High temperature durability has been achieved by using nanocomposites and high temperature annealing. Mechanical durability on thermal cycling have also been investigated and optimized. This technology is promising for commercial applications in next-generation high-temperature concentration solar power (CSP) plants.

  8. Parylene C coating for high-performance replica molding.

    Science.gov (United States)

    Heyries, Kevin A; Hansen, Carl L

    2011-12-07

    This paper presents an improvement to the soft lithography fabrication process that uses chemical vapor deposition of poly(chloro-p-xylylene) (parylene C) to protect microfabricated masters and to improve the release of polymer devices following replica molding. Chemical vapor deposition creates nanometre thick conformal coatings of parylene C on silicon wafers having arrays of 30 μm high SU8 pillars with densities ranging from 278 to 10,040 features per mm(2) and aspect ratios (height : width) from 1 : 1 to 6 : 1. A single coating of parylene C was sufficient to permanently promote poly(dimethyl)siloxane (PDMS) mold release and to protect masters for an indefinite number of molding cycles. We also show that the improved release properties of parylene treated masters allow for fabrication with hard polymers, such as poly(urethane), that would otherwise not be compatible with SU8 on silicon masters. Parylene C provides a robust and high performance mold release coating for soft lithography microfabrication that extends the life of microfabricated masters and improves the achievable density and aspect ratio of replicated features.

  9. Fuel efficiency and fouling control coatings in maritime transport

    DEFF Research Database (Denmark)

    Lindholdt, Asger

    . As a result, it was determined that other methods must be explored in order to accurately measure the long-term drag performance of FCCs in conditions that mimic those encountered by ships’ hulls during actual voyages. In an experimental study, five commercial FCC systems were applied to smooth disks......, compared to the two SPC coatings. Furthermore, the drag performances of two different FCC systems with varying substrate roughness values (i.e., the roughness below the coating system) were measured in the newly applied condition.An increase in the substrate roughness led to increased drag for both FCC......’s hull, and a second, laboratory part measured the torque (drag) of coated cylinders in a rotary setup. Four commercial FCCs were exposed for 53 weeks in Roskilde Fjord, Denmark, i.e., in relatively cold seawater (salinity of 1.2 wt%), from the spring of 2013 to the autumn of 2014. The in situ immersion...

  10. Drag resistance of ship hulls: Effects of surface roughness of newly applied fouling control coatings, coating water absorption, and welding seams

    DEFF Research Database (Denmark)

    Wang, Xueting; Olsen, Stefan Møller; Andrés, Eduardo

    2018-01-01

    selected, that a so-called fouling release (FR) coating caused approximately 5.6 % less skin friction (torque) over time than traditional biocide-based antifouling (AF) coatings at a tangential speed of 12 knots. Furthermore, results of immersion experiments and supporting “standard” water absorption......Fouling control coatings (FCCs) and irregularities (e.g. welding seams) on ship hull surfaces have significant effects on the overall drag performance of ships. In this work, skin frictions of four newly applied FCCs were compared using a pilot-scale rotary setup. Particular attention was given...

  11. Sacrificial Protective Coating Materials that can be Regenerated In-Situ to Enable High Performance Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Malati, Peter; Ganguli, Rahul; Mehrotra, Vivek

    2018-03-20

    control the deposition time, which allows us to deposit the coating on large-scale membranes. We tuned the coating chemistry by introducing positive or negative charges to reject divalent ions present in weak black liquor permeate. Therefore, our two-stage membrane system effectively separates high molecular weight organics from weak black liquor using ultrafiltration membranes (Stage 1) and low molecular weight organic molecules and divalent salts from weak black liquor permeate using nanofiltration membranes (Stage 2), while the coating maintains the permeate flux by mitigating fouling. Coated polymeric ultrafiltration membranes have exhibited up to two-fold increase in permeate flux due to substantially lower fouling when concentrating weak black liquor at 85 °C. Coated tubular ceramic membranes show no observable fouling over a period of 72 hours, compared to uncoated membranes that exhibit a 20% drop in flux in less than 3 hours. Beyond 20% permeate recovery, however, the fouling rate for coated and uncoated membranes approached -0.4 LMH/h due to cake-layer formation. This fouling has been shown to be reversible only with coated membranes; uncoated membranes undergo irreversible fouling and the flux only recovers after chemical cleaning. Continuous surface renewal has been demonstrated using coated membranes that have been stripped and recoated with no loss in performance. Coated Stage 2 membranes exhibit increased sodium sulfate and sodium hydroxide rejection over uncoated membranes. Membranes that are coated with the negatively and positively charged coating exhibit a 7% and 10% increase in sulfate rejection, respectively, over uncoated membranes. Total organic carbon and sodium sulfate analyses of the final Stage 2 permeate and samples from WestRock pulp washers indicate that the permeate may be introduced to the pulp-washing cycle at the first or second washer closest to the digester. Coated Stage 1 membranes exhibit an average permeate flux of 4.2 LMH/bar when

  12. Antimicrobial beeswax coated polylactide films with silver control release capacity.

    Science.gov (United States)

    Martínez-Abad, Antonio; Lagarón, Jose Maria; Ocio, María Jose

    2014-03-17

    Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrated a high burst release which in some instances implied surpassing some current migration restrictions (food), the addition of a beeswax layer allowed a sustained release of the antimicrobial compound. Increasing the thickness of the beeswax layer resulted in an increase in the water barrier properties of the films while reducing the relatively constant values of sustained release. Antimicrobial performance was correlated with the release of silver ions, indicating threshold concentrations for biocide action of films displayed a strong bactericidal effect against Salmonella enterica. The application of this functional barrier thus offers the possibility of tuning the release profiles of the films to suit a specific application and puts forth the possible suitability of these materials for food packaging or other migration sensitive applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Demonstration and Validation of Two Coat High Performance Coating System for Steel Structures in Corrosive Environments

    Science.gov (United States)

    2016-12-01

    Many of these steel buildings and equipment are tradi- tionally painted with an alkyd enamel or waterborne coating for a top coat. These paint systems...bridging minor cracks or for surfaces that have vi- bration and/or movement. These qualities are necessary in a barrier coat- ing primer for it to remain

  14. Multilayer composition coatings for cutting tools: formation and performance properties

    Science.gov (United States)

    Tabakov, Vladimir P.; Vereschaka, Anatoly S.; Vereschaka, Alexey A.

    2018-03-01

    The paper considers the concept of a multi-layer architecture of the coating in which each layer has a predetermined functionality. Latest generation of coatings with multi-layered architecture for cutting tools secure a dual nature of the coating, in which coatings should not only improve the mechanical and physical characteristics of the cutting tool material, but also reduce the thermo-mechanical effect on the cutting tool determining wear intensity. Here are presented the results of the development of combined methods of forming multi-layer coatings with improved properties. Combined method of forming coatings using a pulsed laser allowed reducing excessively high levels of compressive residual stress and increasing micro hardness of the multilayered coatings. The results in testing coated HSS tools showed that the use of additional pulse of laser processing increases tool life up to 3 times. Using filtered cathodic vacuum arc deposition for the generation of multilayer coatings based on TiAlN compound has increased the wear-resistance of carbide tools by 2 fold compared with tool life of cutting tool with commercial TiN coatings. The aim of this study was to develop an innovative methodological approach to the deposition of multilayer coatings for cutting tools with functional architectural selection, properties and parameters of the coating based on sound knowledge of coating failure in machining process.

  15. Design and performance of differential pumping system of coating unit

    International Nuclear Information System (INIS)

    Karmakar, P; Maiti, N; Bapat, A V

    2008-01-01

    A box type coating unit has been developed in view of dual purpose of optical and reactive coating. The system is divided in two parts namely, substrate chamber (800mm x 800 mm x 100 mm) and gun chamber (800mm x 800 mm x 100 mm). Coating material is evaporated in the substrate chamber by traverse (270 deg.) electron beams. Reactive gas is injected in the substrate chamber by up-stream pressure controller to reach set pressures in the range of 1x10 -3 mbar to 1x10 -4 mbar for gas flow rate in the range of 0-30 sccm. Traverse EB guns (10 kV, 15 kW, 2 No) are mounted inside gun chamber. The gun chamber vacuum should be better than 1x10 -5 mbar for the operation of EB guns. Both these chambers are connected by the apertures provided on the intermediate bifurcation plate for the passage of electron beams. Through the apertures the reactive gas leaks from the substrate chamber to the gun chamber due to differential pressure. The differential pumping system consists of individual pumping modules for the substrate chamber and the gun chamber. The paper focuses upon the design of differential pumping system in view of determination of steady state differential pressures for different flow rates of reactive gas. It has been noticed that on introduction of reactive gas in the substrate chamber, the pressures in the substrate chamber and the gun chamber oscillates before converging to steady state values. Theoretically calculated values have been compared with the experimental values as design validation

  16. Development of diamond coated tool and its performance in ...

    Indian Academy of Sciences (India)

    Unknown

    Mechanical Engineering Department, Indian Institute of Technology, Kharagpur 721 302, India ... chemical inertness of diamond coating towards the work material, did not show any .... CVD diamond coated carbide tools, Ph D Thesis, Indian.

  17. In vitro performance of ceramic coatings obtained by high velocity oxy-fuel spray.

    Science.gov (United States)

    Melero, H; Garcia-Giralt, N; Fernández, J; Díez-Pérez, A; Guilemany, J M

    2014-01-01

    Hydroxyapatite coatings obtained by plasma-spraying have been used for many years to improve biological performance of bone implants, but several studies have drawn attention to the problems arising from high temperatures and the lack of mechanical properties. In this study, plasma-spraying is substituted by high velocity oxy-fuel (HVOF) spray, with lower temperatures reached, and TiO2 is added in low amounts to hydroxyapatite in order to improve the mechanical properties. Four conditions have been tested to evaluate which are those with better biological properties. Viability and proliferation tests, as well as differentiation assays and morphology observation, are performed with human osteoblast cultures onto the studied coatings. The hydroxyapatite-TiO2 coatings maintain good cell viability and proliferation, especially the cases with higher amorphous phase amount and specific surface, and promote excellent differentiation, with a higher ALP amount for these cases than for polystyrene controls. Observation by SEM corroborates this excellent behaviour. In conclusion, these coatings are a good alternative to those used industrially, and an interesting issue would be improving biological behaviour of the worst cases, which in turn show the better mechanical properties.

  18. Material-Process-Performance Relationships for Roll-to-Roll Coated PEM Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, Scott; Neyerlin, K.C.; Stickel, Jonathan; Ulsh, Michael; More, Karren; Wood, David

    2017-04-26

    Roll-to-roll (R2R) coating is the most economical and highest throughput method for producing fuel cell electrodes. R2R coating encompasses many different methodologies to create uniform films on a moving web substrate. Here we explore two coating methods, gravure and slot die, to understand the impacts of each on film uniformity and performance.

  19. Plasma-Sprayed ZnO/TiO2 Coatings with Enhanced Biological Performance

    Science.gov (United States)

    Zhao, Xiaobing; Peng, Chao; You, Jing

    2017-08-01

    Surface chemical composition and topography are two key factors in the biological performance of implants. The aim of this work is to deposit ZnO/TiO2 composite coatings on the surface of titanium substrates by plasma spraying technique. The effects of the amount of ZnO doping on the microstructure, surface roughness, corrosion resistance, and biological performance of the TiO2 coatings were investigated. The results indicated that the phase composition of the as-sprayed TiO2 coating was mainly rutile. Addition of 10% ZnO into TiO2 coating led to a slight shift of the diffraction peaks to lower angle. Anatase phase and Zn2TiO4 were formed in 20%ZnO/TiO2 and 30%ZnO/TiO2 coatings, respectively. Doping with ZnO changed the topography of the TiO2 coatings, which may be beneficial to enhance their biological performance. All coatings exhibited microsized surface roughness, and the corrosion resistance of ZnO/TiO2 coatings was improved compared with pure TiO2 coating. The ZnO/TiO2 coatings could induce apatite formation on their surface and inhibit growth of Staphylococcus aureus, but these effects were dose dependent. The 20%ZnO/TiO2 coating showed better biological performance than the other coatings, suggesting potential application for bone implants.

  20. Investigation on hard coating of pivot-jewel bearing and wearing performance

    International Nuclear Information System (INIS)

    Han Kun; Dai Xingjian

    2014-01-01

    The reliability of high speed rotating machine is related to the anti-wear properties of pivot jewel bearing used in the system. To reduce its wearing process, hard coating method is used on the steel pivot. Through the wearing test on specialized facilities, its founded that the TiN coating shows better performance than DLC coating, and multi-layer TiN coating can slow down the pivot's wearing process obviously compared to other methods. (authors)

  1. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    Directory of Open Access Journals (Sweden)

    Zheng-gang Xiao

    2014-06-01

    Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

  2. Controlling the radiative properties of cool black-color coatings pigmented with CuO submicron particles

    International Nuclear Information System (INIS)

    Gonome, Hiroki; Baneshi, Mehdi; Okajima, Junnosuke; Komiya, Atsuki; Maruyama, Shigenao

    2014-01-01

    The objective of this study was to design a pigmented coating with dark appearance that maintains a low temperature while exposed to sunlight. The radiative properties of a black-color coating pigmented with copper oxide (CuO) submicron particles are described. In the present work, the spectral behavior of the CuO-pigmented coating was calculated. The radiative properties of CuO particles were evaluated, and the radiative transfer in the pigmented coating was modeled using the radiation element method by ray emission model (REM 2 ). The coating is made using optimized particles. The reflectivity is measured by spectroscopy and an integrating sphere in the visible (VIS) and near infrared (NIR) regions. By using CuO particles controlled in size, we were able to design a black-color coating with high reflectance in the NIR region. The coating substrate also plays an important role in controlling the reflectance. The NIR reflectance of the coating on a standard white substrate with appropriate coating thickness and volume fraction was much higher than that on a standard black substrate. From the comparison between the experimental and calculated results, we know that more accurate particle size control enables us to achieve better performance. The use of appropriate particles with optimum size, coating thickness and volume fraction on a suitable substrate enables cool and black-color coating against solar irradiation. -- Highlights: • A new approach in designing pigmented coatings was used. • The effects of particles size on both visible and near infrared reflectivities were studied. • The results of numerical calculation were compared with experimental ones for CuO powders

  3. Wettability control by DLC coated nanowire topography

    Science.gov (United States)

    Li, Zihui; Meng, Fanhao; Liu, Xuanyong

    2011-04-01

    Here we have developed a convenient method to fabricate wettability controllable surfaces that can be applied to various nanostructured surfaces with complex shapes for different industrial needs. Diamond-like carbon (DLC) films were synthesized on titanium substrate with a nanowire structured surface using plasma immersion ion implantation and deposition (PIII&D). The nanostructure of the DLC films was characterized by field emission scanning electron microscopy and found to grow in a rippling layer-by-layer manner. Raman spectroscopy was used to investigate the different bonding presented in the DLC films. To determine the wettability of the samples, water contact angles were measured and found to vary in the range of 50°-141°. The results indicated that it was critical to construct a proper surface topography for high hydrophobicity, while suitable ID/IG and sp2/sp3 ratios of the DLC films had a minor contribution. Superhydrophobicity could be achieved by further CF4 implantation on suitably structured DLC films and was attributed to the existence of fluorine. In order to maintain the nanostructure during CF4 implantation, it was favorable to pre-deposit an appropriate carbon content on the nanostructure, as a nanostructure with low carbon content would be deformed during CF4 implantation due to local accumulation of surface charge and the following discharge resulting from the low conductivity.

  4. Composition Effects on Aluminide Oxidation Performance: Objectives for Improved Bond Coats

    International Nuclear Information System (INIS)

    Pint, BA

    2001-01-01

    Formerly, the role of metallic coatings on Ni-base superalloys was simply to limit environmental attack of the underlying substrate. However, a new paradigm has been established for metallic coatings adapted as bond coats for thermal barrier coatings. It is no longer sufficient for the coating to just minimize the corrosion rate. The metallic coating must also form a slow-growing external Al(sub 2)O(sub 3) layer beneath the overlying low thermal conductivity ceramic top coat. This thermally grown oxide or scale must have near-perfect adhesion in order to limit spallation of the top coat, thereby achieving a long coating lifetime. While oxidation is not the only concern in complex thermal barrier coating systems, it is, however, a primary factor in developing the next generation of bond coats. Therefore, a set of compositional guidelines for coatings is proposed in order to maximize oxidation performance. These criteria are based on test results of cast alloy compositions to quantify an d understand possible improvements as a basis for further investigations using coatings made by chemical vapor deposited (CVD). Experimental work includes furnace cycle testing and in-depth characterization of the alumina scale, including transmission electron microscopy (TEM)

  5. Nanoparticle-coated separators for lithium-ion batteries with advanced electrochemical performance

    KAUST Repository

    Fang, Jason; Kelarakis, Antonios; Lin, Yueh-Wei; Kang, Chi-Yun; Yang, Ming-Huan; Cheng, Cheng-Liang; Wang, Yue; Giannelis, Emmanuel P.; Tsai, Li-Duan

    2011-01-01

    We report a simple, scalable approach to improve the interfacial characteristics and, thereby, the performance of commonly used polyolefin based battery separators. The nanoparticle-coated separators are synthesized by first plasma treating the membrane in oxygen to create surface anchoring groups followed by immersion into a dispersion of positively charged SiO 2 nanoparticles. The process leads to nanoparticles electrostatically adsorbed not only onto the exterior of the surface but also inside the pores of the membrane. The thickness and depth of the coatings can be fine-tuned by controlling the ζ-potential of the nanoparticles. The membranes show improved wetting to common battery electrolytes such as propylene carbonate. Cells based on the nanoparticle-coated membranes are operable even in a simple mixture of EC/PC. In contrast, an identical cell based on the pristine, untreated membrane fails to be charged even after addition of a surfactant to improve electrolyte wetting. When evaluated in a Li-ion cell using an EC/PC/DEC/VC electrolyte mixture, the nanoparticle-coated separator retains 92% of its charge capacity after 100 cycles compared to 80 and 77% for the plasma only treated and pristine membrane, respectively. © the Owner Societies 2011.

  6. Effect of Surface Contaminants Remained on the Blasted Surface on Epoxy Coating Performance and Corrosion Resistance

    International Nuclear Information System (INIS)

    Baek, Kwang Ki; Park, Chung Seo; Kim, Ki Hong; Chung, Mong Kyu; Park, Jin Hwan

    2006-01-01

    One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities

  7. Corrosion Protection of Al Alloys for Aircraft by Coatings With Advanced Properties and Enhanced Performance

    National Research Council Canada - National Science Library

    Bierwagen, Gordon; Croll, Stuart; Webster, Dean; Tallman, Dennis; Huo, Qun; Allahar, Brian; Su, Quan; Bonitz, Verena; Fernando, Dilhan; Wang, Duhua

    2007-01-01

    The report presents research that addresses research performed at NDSU for environmentally compliant corrosion protection in coatings systems of greatly extended lifetimes for present and future aircraft...

  8. Coating Performance in Duluth Superior Harbor. Part 2

    Science.gov (United States)

    2012-10-01

    tures in fresh water , and nine coatings were evaluated for corrosion protection of CS coupons and I-beams around DSH after 46 and 35 months...following coatings were selected for this evaluation: 1 Aquapure HR* 2 Chevron Phillips 1ZSMV 3 Standard epoxy 4 HumidurML* 5 Wasser MC-zinc/MC-tar* 6...one option for protection of extensive structures in fresh water , and nine coatings were evaluated for corrosion protection of CS coupons and I-beams

  9. Solution Coating of Superior Large-Area Flexible Perovskite Thin Films with Controlled Crystal Packing

    KAUST Repository

    Li, Jianbo

    2017-05-08

    Solution coating of organohalide lead perovskites offers great potential for achieving low-cost manufacturing of large-area flexible optoelectronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of crystal packing. Herein, this study reports using solution shearing to confine crystal nucleation and growth in large-area printed MAPbI3 thin films. Near single-crystalline perovskite microarrays are demonstrated with a high degree of controlled macroscopic alignment and crystal orientation, which exhibit significant improvements in optical and optoelectronic properties comparing with their random counterparts, spherulitic, and nanograined films. In particular, photodetectors based on the confined films showing intense anisotropy in charge transport are fabricated, and the device exhibits significantly improved performance in all aspects by one more orders of magnitude relative to their random counterparts. It is anticipated that perovskite films with controlled crystal packing may find applications in high-performance, large-area printed optoelectronics, and solar cells.

  10. Solution Coating of Superior Large-Area Flexible Perovskite Thin Films with Controlled Crystal Packing

    KAUST Repository

    Li, Jianbo; Liu, Yucheng; Ren, Xiaodong; Yang, Zhou; Li, Ruipeng; Su, Hang; Yang, Xiaoming; Xu, Junzhuo; Xu, Hua; Hu, Jian-Yong; Amassian, Aram; Zhao, Kui; Liu, Shengzhong Frank

    2017-01-01

    Solution coating of organohalide lead perovskites offers great potential for achieving low-cost manufacturing of large-area flexible optoelectronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of crystal packing. Herein, this study reports using solution shearing to confine crystal nucleation and growth in large-area printed MAPbI3 thin films. Near single-crystalline perovskite microarrays are demonstrated with a high degree of controlled macroscopic alignment and crystal orientation, which exhibit significant improvements in optical and optoelectronic properties comparing with their random counterparts, spherulitic, and nanograined films. In particular, photodetectors based on the confined films showing intense anisotropy in charge transport are fabricated, and the device exhibits significantly improved performance in all aspects by one more orders of magnitude relative to their random counterparts. It is anticipated that perovskite films with controlled crystal packing may find applications in high-performance, large-area printed optoelectronics, and solar cells.

  11. Performances and reliability of WC based thermal spray coatings

    International Nuclear Information System (INIS)

    Scrivani, A.; Rosso, M.; Salvarani, L.

    2001-01-01

    Thermal spray processes are used for a lot of traditional and innovative applications and their importance is becoming higher and higher. WC/CoCr based thermal spray coatings represent one of the most important class of coatings that find application in a wide range of industrial sectors. This paper will address a review of current applications and characteristics of this kind of coating. The most important spraying processes, namely HVOF (high velocity oxygen fuel) are examined, the characterization of the coatings from the point of view of corrosion and wear resistance is considered. (author)

  12. Development of control system of coating of rod hydraulic cylinders

    Science.gov (United States)

    Aizhambaeva, S. Zh; Maximova, A. V.

    2018-01-01

    In this article, requirements to materials of hydraulic cylinders and methods of eliminating the main factors affecting the quality of the applied coatings rod hydraulic cylinders. The chromium plating process - one of ways of increase of anti-friction properties of coatings rods, stability to the wear and corrosion. The article gives description of differences of the stand-speed chromium plating process from other types of chromium plating that determines a conclusion about cutting time of chromium plating process. Conducting the analysis of technological equipment suggested addressing the modernization of high-speed chromium plating processes by automation and mechanization. Control system developed by design of schematic block diagram of a modernized and stand-speed chromium plating process.

  13. Tests results and performance comparisons of coated and un-coated skutterudite based segmented unicouples

    International Nuclear Information System (INIS)

    El-Genk, Mohamed S.; Saber, Hamed H.; Caillat, Thierry; Sakamoto, Jeff

    2006-01-01

    Skutterudite based thermoelectric unicouples are being considered for use in Advanced Radioisotope Power Systems (ARPSs) to support NASA's planetary exploration missions. For these systems, which would be much lighter than state of the art Radioisotope Thermoelectric Generators (RTGs), it is important to ensure minimal degradation in the performance of unicouples that may be caused by material sublimation. In this work, two unicouples, JAN-04 with a thin metallic coating on the legs near the hot junction to suppress antimony sublimation and SEP-03 without coating, are tested for >1000 and 3600 h, respectively. The legs in the two unicouples are of almost the same dimensions and compositions; the p-legs are made of CeFe 3.5 Co 0.5 Sb 12 and Bi 0.4 Sb 1.6 Te 3 segments and the n-legs are made of CoSb 3 and Bi 2 Te 2.95 Se 0.05 segments. SEP-03 is tested at average hot and cold junction temperatures of 961.5 ± 22.0 and 296.3 ± 5.7 K, respectively, in argon gas at ∼0.068 MPa, and JAN-04 is tested at 962.8 ± 20.5 and 294.5 ± 3.3 K, respectively, initially in argon gas at the same pressure for ∼26.5 h then in vacuum ∼9.0 x 10 -7 Torr for >973.5 h. The measured open circuit voltage V oc (240 mV) and peak electrical power (1.64 W e ) for SEP-03 at the beginning of test (BOT) are higher than those for JAN-04 (188 mV and 0.84 W e , respectively). Although the argon gas effectively decreased the antimony loss from the legs of SEP-03, marked degradations in performance occurred. The estimated peak efficiency for SEP-03 decreased from 13.8% at BOT to 5.8% at end of test (EOT), and the peak power decreased from 1.64 W e at BOT to 0.48 W e at EOT, however, V oc decreased by ∼14%. The latter for JAN-04 decreased only by ∼3%, the estimated peak efficiency (∼12%) changed very little and the peak power decreased by ∼20%. Unlike SEP-03, the measured total and contact resistances of the legs in JAN-04 changed very little

  14. The Effect of Particle Size of Wollastonite Filler on Thermal Performance of Intumescent Fire Retardant Coating

    Directory of Open Access Journals (Sweden)

    Zia-ul-Mustafa M.

    2014-07-01

    Full Text Available Intumescent Fire retardant coatings (IFRC’s are one of the simplest ways to protect substrates exposed to fire. In this study, Wollastonite (W filler of two different particle sizes were used to determine the fire performance of intumescent fire retardant coating. The basic ingredients of the coating were ammonium poly-phosphate (APP as acid source, expandable graphite (EG as carbon source, melamine (MEL as blowing agent in epoxy binder, boric acid as additive and hardener as curing agent. A series of coating formulations were developed by using different weight percentages of both sized Wollastonite fillers. The coated steel substrate samples were tested for fire performance using Bunsen burner and char expansion was measured using furnace fire test. A Comparison of the coatings thermal performance was determined. Wollastonite containing filler particle size 10 μm showed better thermal performance than formulations containing filler’s particle size 44 μm.

  15. Analysis of genetic variants of coat colour loci and their influence on the coat colour phenotype and quantitative performance traits in the pig

    OpenAIRE

    Siebel, Krista

    2010-01-01

    The influence of four single coat colour loci (KIT, MC1R, TYR, ASP) on the coat colour phenotype and performance traits in the pig have been investigated in a resource population. The research revealed an unknown genotype for the white phenotype in the pig. The influence of the Agouti locus on the coat colour phenotype has been suggested. An influence of the coat colour loci KIT on growth performance traits and MC1R on body fatness could be demonstrated.

  16. Novel hybrid coatings with controlled wettability by composite nanoparticle aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Hritcu, Doina, E-mail: dhritcu@ch.tuiasi.ro; Dodi, Gianina; Iordache, Mirabela L.; Draganescu, Dan; Sava, Elena; Popa, Marcel I.

    2016-11-30

    Highlights: • Magnetite-grafted chitosan composite nanoparticles were synthesized. • The particles are able to assemble under the influence of a silane derivative. • Thin films containing composites, chitosan and hydrolyzed silane were optimized. • The novel hybrid coatings show hierarchical roughness and high wetting angle. - Abstract: The aim of this study is to evaluate novel hybrid materials as potential candidates for producing coatings with hierarchical roughness and controlled wetting behaviour. Magnetite (Fe{sub 3}O{sub 4}) nanoparticles obtained by co-precipitation were embedded in matrices synthesized by radical graft co-polymerization of butyl acrylate (BA), butyl methacrylate (BMA), hexyl acrylate (HA) or styrene (ST) with ethylene glycol di-methacrylate (EGDMA) onto previously modified chitosan bearing surface vinyl groups. The resulting composite particles were characterized regarding their average size, composition and magnetic properties. Hybrid thin films containing suspension of composite particles in ethanol and pre-hydrolysed hexadecyltrimethoxysilane (HDTS) as a coupling/crosslinking agent were deposited by spin coating or spraying. The films were cured by heating and subsequently characterized regarding their morphology (scanning electron microscopy), contact angle with water and adhesion to substrate (scratch test). The structure-property relationship is discussed.

  17. Friction, adhesion and corrosion performance of metallurgical coatings in HTGR-helium

    International Nuclear Information System (INIS)

    Engel, R.; Kleemann, W.

    1981-01-01

    The friction-, adhesion-, thermal cycling- and corrosion performance of several metallurgical coating systems have been tested in a simulated HTGR-test atmosphere at elevated temperatures. The coatings were applied to a solid solution strengthened Ni-based superalloy. Component design requires coatings for the protection of mating surfaces, since under reactor operating conditions, contacting surfaces of metallic components under high pressures are prone to friction and wear damage. The coatings will have to protect the metal surface for 30 years up to 950 0 C in HTGR-helium. The materials tested were various refractory carbides with or without metallic binders and intermetallic compounds. The coatings evaluated were applied by plasma spraying-, detonation gun- and chemical vapor deposition techniques. These yielded two types of coatings which employ different mechanisms to improve the tribiological properties and maintain coating integrity. (Auth.)

  18. Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

    Directory of Open Access Journals (Sweden)

    Vikram Devaraj

    2015-01-01

    Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

  19. Controlled reactions between chromia and coating on alloy surface

    DEFF Research Database (Denmark)

    Linderoth, Søren

    1996-01-01

    An electrically conducting Sr-doped lanthanum chromite (LSC) coating has been produced by reacting a coating of fine particles of La oxide and Sr oxide with chromia formed as an external scale on a metallic alloy. In addition to the formation of LSC the coating also resulted in much reduced...... buckling of the underlying chromia layer compared with a non-coated alloy....

  20. Control of Flux Pinning in MOD YBCO Coated Conductor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W. [American Superconductor Corporation, Westborough, MA; Huang, Y. [American Superconductor Corporation, Westborough, MA; Li, X. [American Superconductor Corporation, Westborough, MA; Kodenkandath, Thomas [American Superconductor Corporation, Westborough, MA; Rupich, Marty [American Superconductor Corporation, Westborough, MA; Schoop, U. [American Superconductor Corporation, Westborough, MA; Verebelyi, D. T. [American Superconductor Corporation, Westborough, MA; Thieme, C. L. H. [American Superconductor Corporation, Westborough, MA; Siegal, E. E. [American Superconductor Corporation, Westborough, MA; Holesinger, T. G. [Los Alamos National Laboratory (LANL); Maiorov, B. [Los Alamos National Laboratory (LANL); Miller, D. J. [Argonne National Laboratory (ANL); Maroni, V. A. [Argonne National Laboratory (ANL); Goyal, Amit [ORNL; Specht, Eliot D [ORNL; Paranthaman, Mariappan Parans [ORNL

    2007-01-01

    Two different types of defect structures have been identified to be responsible for the enhanced pinning in metal organic deposited YBCO films. Rare earth additions result in the formation of nanodots in the YBCO matrix, which form uncorrelated pinning centers, increasing pinning in all magnetic field orientations. 124-type intergrowths, which form as laminar structures parallel to the ab-plane, are responsible for the large current enhancement when the magnetic field is oriented in the ab-plane. TEM studies showed that the intergrowths emanate from cuprous containing secondary phase particles, whose density is partially controlled by the rare earth doping level. Critical process parameters have been identified to control this phase formation, and therefore, control the f 24 intergrowth formation. This work has shown that through process control and proper conductor design, either by adjusting the composition or by multiple coatings of different functional layers, the desired angular dependence can be achieved.

  1. Control of flux pinning in MOD YBCO coated conductor.

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Huang, Y.; Li, X.; Kodenkandath, T.; Rupich, M. W.; Schoop, U.; Verebelyi, D. T.; Thieme, C. L. H.; Siegal, E.; Holesinger, T. G.; Maiorov, B.; Civale, L.; Miller, D. J.; Maroni, V. A.; Li, J.; Martin, P. M.; Specht, E. D.; Goyal, A.; Paranthaman, M. P.; American Superconductor Corp.; LANL; ORNL

    2007-06-01

    NTwo different types of defect structures have been identified to be responsible for the enhanced pinning in metal organic deposited YBCO films. Rare earth additions result in the formation of nanodots in the YBCO matrix, which form uncorrelated pinning centers, increasing pinning in all magnetic field orientations. 124-type intergrowths, which form as laminar structures parallel to the ab-plane, are responsible for the large current enhancement when the magnetic field is oriented in the ab-plane. TEM studies showed that the intergrowths emanate from cuprous containing secondary phase particles, whose density is partially controlled by the rare earth doping level. Critical process parameters have been identified to control this phase formation, and therefore, control the f 24 intergrowth formation. This work has shown that through process control and proper conductor design, either by adjusting the composition or by multiple coatings of different functional layers, the desired angular dependence can be achieved.

  2. Coating of Ultra-Small Micro End Mills: Analysis of Performance and Suitability of Eight Different Hard-Coatings

    Directory of Open Access Journals (Sweden)

    Martin Bohley

    2018-03-01

    Full Text Available Due to the constant need for better functionalized surfaces or smaller, function integrated components, precise and efficient manufacturing processes have to be established. Micro milling with micro end mills is one of the most promising processes for this task as it combines a high geometric flexibility in a wide range of machinable materials with low set-up costs. A downside of this process is the wear of the micro end mills. Due to size effects and the relatively low cutting speed, the cutting edge is especially subjected to massive abrasive wear. One possibility to minimize this wear is coating of micro end mills. This research paper describes the performance of eight different hard coatings for micro end mills with a diameter <40 µm and discusses some properties for the best performing coating type. With this research, it is therefore possible to boost the possibilities of micro milling for the manufacture of next generation products.

  3. THE MEASURABILITY OF CONTROLLING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    V. Laval

    2017-04-01

    Full Text Available The urge to increase the performance of company processes is ongoing. Surveys indicate however, that many companies do not measure the controlling performance with a defined set of key performance indicators. This paper will analyze three categories of controlling key performance indicators based on their degree of measurability and their impact on the financial performance of a company. Potential measures to optimize the performance of the controlling department will be outlined and put in a logical order. The aligning of the controlling activity with the respective management expectation will be discussed as a key success factor of this improvement project.

  4. Performance and Internal Control

    OpenAIRE

    Mifti, Sri; Lestariyo, Nugroho Budi; Kowanda, Anacostia

    2009-01-01

    The objective of this study is to measure the influence of internal auditing on performance. Research object is Inspectorate General Department of Home Affairs staffs. As research instrument, questionnaire was developed and distributed to respondents. Closed type questionnaire was developed with five (5) choices to measure the two (2) research variables. Internal auditing is measured using six (6) dimensions, and performance is measured using three (3) dimensions. As the two variables are lat...

  5. In vitro biological performance of minerals substituted hydroxyapatite coating by pulsed electrodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, Dhanaraj, E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Karthika, Arumugam; Nithiya, Subramani [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Kavitha, Louis [Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India)

    2014-03-01

    The present study deals with the optimization of minerals (Sr, Mg and Zn) substituted hydroxyapatite coatings (M-HAP) at different pulse on and off time (1 s, 2 s, 3 s and 4 s) by pulsed electrodeposition method. The formation of M-HAP coating was investigated using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction studies (XRD). The morphological features and the content of Sr, Mg and Zn ions in M-HAP coated Ti–6Al–4V were investigated by high resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray analysis (EDAX). The electrochemical studies were performed for M-HAP coated Ti–6Al–4V in simulated body fluid which exhibited better corrosion resistance at the prolonged pulse off time. The in vitro cell adhesion test revealed that the M-HAP coating is found appropriate for the formation of new cell growth which proves the enhanced biocompatible nature of the coating. Thus the M-HAP coating will serve as a potential candidate in orthopedic applications. - Highlights: • We successfully achieved minerals substituted HAP coatings on Ti alloy by PED method. • The M-HAP coated Ti alloy exhibited better bioresistivity in SBF. • The as-coated sample showed antimicrobial activity and better cell viability. • The in vitro test displayed the formation of new cell growth. • The M-HAP coating can serve as a better candidate in orthopedic applications.

  6. Correlating Coating Characteristics with the Performance of Drug-Coated Balloons – A Comparative In Vitro Investigation of Own Established Hydrogel- and Ionic Liquid-Based Coating Matrices

    Science.gov (United States)

    Kaule, Sebastian; Minrath, Ingo; Stein, Florian; Kragl, Udo; Schmidt, Wolfram; Schmitz, Klaus-Peter; Sternberg, Katrin; Petersen, Svea

    2015-01-01

    Drug-coated balloons (DCB), which have emerged as a therapeutic alternative to drug-eluting stents in percutaneous cardiovascular intervention, are well described with regard to clinical efficacy and safety within a number of clinical studies. In vitro studies elucidating the correlation between coating additive and DCB performance are however rare but considered important for the understanding of DCB requirements and the improvement of established DCB. In this regard, we examined three different DCB-systems, which were developed in former studies based on the ionic liquid cetylpyridinium salicylate, the body-own hydrogel hyaluronic acid and the pharmaceutically well-established hydrogel polyvinylpyrrolidone, considering coating morphology, coating thickness, drug-loss, drug-transfer to the vessel wall, residual drug-concentration on the balloon surface and entire drug-load during simulated use in an in vitro vessel model. Moreover, we investigated particle release of the different DCB during simulated use and determined the influence of the three coatings on the mechanical behavior of the balloon catheter. We could show that coating characteristics can be indeed correlated with the performance of DCB. For instance, paclitaxel incorporation in the matrix can reduce the drug wash-off and benefit a high drug transfer. Additionally, a thin coating with a smooth surface and high but delayed solubility can reduce drug wash-off and decrease particle burden. As a result, we suggest that it is very important to characterize DCB in terms of mentioned properties in vitro in addition to their clinical efficacy in order to better understand their function and provide more data for the clinicians to improve the tool of DCB in coronary angioplasty. PMID:25734818

  7. Development and characterization of nano structured hard coatings for high performance tools by using PVD technique

    International Nuclear Information System (INIS)

    Irfan, M.; Alam, S.; Hassan, Z.; Iftikhar, F.; Khadim, S.

    2006-01-01

    No doubt hard coatings nave major applications in high performance cutting tools in order to improve tribological and mechanical properties of these tools since last years. The actual top development in this regard is the development of PVD based AlTiN coatings and their supplementation with nano. layers. In present these nano coatings are replaced by nano composites along with an additional development of Multilayer Nano structured coatings. This PVD based nano structured coating development optimized by process parameters, crystalline structure and deposition in multilayer. These coating are definitely produced by combination of ARC and Sputtering with filtration of arc droplets. It is studied that the properties like oxidation resistance, wear resistance and resistance against chemical reaction may be obtained by alloying additions of different elements. This paper presents different development stages and Process parameters for- producing high performance Nanostructure coatings and including adhesion test by using Kalomax system for determination of adhesion strength of these coatings and coating thickness measurements by using image analyzer system. Results and conclusions are showing the optimum values for better coatings for different applications. (author)

  8. Corrosion Performance of Nano-ZrO₂ Modified Coatings in Hot Mixed Acid Solutions.

    Science.gov (United States)

    Xu, Wenhua; Wang, Zhenyu; Han, En-Hou; Wang, Shuai; Liu, Qian

    2018-06-01

    A nano-ZrO₂ modified coating system was prepared by incorporation of nano-ZrO₂ concentrates into phenolic-epoxy resin. The corrosion performance of the coatings was evaluated in hot mixed acid solution, using electrochemical methods combined with surface characterization, and the effects of nano-ZrO₂ content were specially focused on. The results showed that 1% and 3% nano-ZrO₂ addition enhanced the corrosion resistance of the coatings, while 5% nano-ZrO₂ addition declined it. The coating with 3% nano-ZrO₂ presented the minimum amount of species diffusion, the lowest average roughness (5.94 nm), and the highest C/O ratio (4.55) and coating resistance, and it demonstrated the best corrosion performance among the coating specimens.

  9. Comparison of performance coatings thermally sprayed subject to testing adhesive wear

    International Nuclear Information System (INIS)

    Marangoni, G.F.; Arnt, A.B.C.; Rocha, M.R. da

    2014-01-01

    In this work, the microstructural changes and wear resistance adhesive coatings obtained from powders thermally sprayed by high velocity oxy-fuel (HVOF) were evaluated. Based coatings chrome-nickel and tungsten-cobalt are applied in conditions subject to intense wear especially abrasive. With the aim of evaluate the performance of these coatings under conditions of adhesive wear, these coatings samples were tested by the standard ASTM G99. As test parameters were used: Tungsten carbide pin (SAE 52100) with 6 mm diameter, normal load of 50N and a tangential velocity of 0.5 m / s. The worn surfaces of the coatings were characterized by optical and scanning electron microscopy and X-ray diffraction. Results indicate that the performance front wear is related to the conditions of adhesion and uniformity of the coating applied. (author)

  10. Thermal analysis of the effect of thick thermal barrier coatings on diesel engine performance

    International Nuclear Information System (INIS)

    Hoag, K.L.; Frisch, S.R.; Yonushonis, T.M.

    1986-01-01

    The reduction of heat rejection from the diesel engine combustion chamber has been the subject of a great deal of focus in recent years. In the pursuit of this goal, Cummins Engine Company has received a contract from the Department of Energy for the development of thick thermal barrier coatings for combustion chamber surfaces. This contract involves the analysis of the impact of coatings on diesel engine performance, bench test evaluation of various coating designs, and single cylinder engine tests. The efforts reported in this paper center on the analysis of the effects of coatings on engine performance and heat rejection. For this analysis the conventional water cooled engine was compared with an engine having limited oil cooling, and utilizing zirocnia coated cylinder had firedecks and piston crowns. The analysis showed little or no benefits of similarly coating the valves or cylinder liner

  11. Trackless tack coat materials : a laboratory evaluation performance acceptance.

    Science.gov (United States)

    2012-06-01

    The purpose of this study was to develop, demonstrate, and document laboratory procedures that could be used by the : Virginia Department of Transportation (VDOT) to evaluate non-tracking tack coat materials. The procedures would be used to : qualify...

  12. Damage and Performance Assessment of Protective Coatings on Turbine Blades

    OpenAIRE

    Pokluda, Jaroslav; Kianicová, Marta

    2010-01-01

    Protective coatings on blades serve as physical barriers between the underlying substrate and the outer environment. This article presents an overview of damage mechanisms leading to failure of all basic types of coatings (diffusion, overlay and thermal barrier) on turbine blades of aircraft engines during service. Although a special emphasize is devoted to destructive effects of thermo-mechanical fatigue and overheating, the severe effects of hot corrosion, oxidation and erosion effects are ...

  13. Advanced Antireflection Coatings for High-Performance Solar Energy Applications

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Phase II objectives: Develop and refine antireflection coatings incorporating lanthanum titanate as an intermediate refractive index material; Investigate wet/dry thermal oxidation of aluminum containing semiconductor compounds as a means of forming a more transparent window layer with equal or better optical properties than its unoxidized form; Develop a fabrication process that allows integration of the oxidized window layer and maintains the necessary electrical properties for contacting the solar cell; Conduct an experimental demonstration of the best candidates for improved antireflection coatings.

  14. Coatings for laser fusion

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1981-01-01

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors

  15. Enhanced electrochemical performance of CoAl-layered double hydroxide nanosheet arrays coated by platinum films

    International Nuclear Information System (INIS)

    Cheng, J.P.; Fang, J.H.; Li, M.; Zhang, W.F.; Liu, F.; Zhang, X.B.

    2013-01-01

    Graphical abstract: Schematic illustration for the electron transport between the current collector and the active CoAl LDH arrays, where the yellow arrows indicate the high resistance of CoAl LDH, while the green arrows present the high conductivity of Pt films on LDH. -- Highlights: •CoAl layered double hydroxide nanosheet arrays are synthesized by hydrothermal method. •Pt films coated on surface of CoAl nanosheets facilitate fast electron transport. •CoAl LDH nanosheets coated with Pt film for 5 min have an excellent performance. -- Abstract: Three-dimensional network of cobalt and aluminum layered double hydroxide (LDH) nanosheets was synthesized on nickel foam by a simple hydrothermal method. The CoAl-LDH nonosheets were subsequently coated by ion sputtering with thin layers of Pt films to facilitate fast electron transport between current collector and the CoAl-LDH active materials. The optimal thickness of the Pt film acquiring the best performance was identified by applying various sputtering time in controlled experiments. The supercapacitor built by the CoAl-LDH nanosheets coated with Pt film sputtered for 5 min has a high specific capacitance (734.4 F g −1 at 3 A g −1 ), excellent rate capability as well as cycling stability. Moreover, it showed a long life of 77% retention after 6000 cycles and its general morphology was preserved after the test. The synergetic affect of conductive layer of Pt films and CoAl-LDH on the improvement of electrochemical properties was discussed and this would provide a useful clue in designing novel and effective electrode materials for supercapacitors

  16. Light controlled friction at a liquid crystal polymer coating with switchable patterning

    NARCIS (Netherlands)

    Liu, D.; Broer, D.J.

    2014-01-01

    We describe a new methodology that enables dynamically control of motion through modulating friction at coating surfaces by exposing with UV light. The principle is based on reversibly switching the surface topographies of the coating by light. The coating surface transfers from flat in the dark to

  17. Corrosion protection performance of single and dual Plasma Electrolytic Oxidation (PEO) coating for aerospace applications

    International Nuclear Information System (INIS)

    Madhan Kumar, A.; Kwon, Sun Hwan; Jung, Hwa Chul; Shin, Kwang Seon

    2015-01-01

    Plasma Electrolytic Oxidation (PEO) coatings are known to be one of the most appropriate method for corrosion protection of magnesium (Mg) alloy. The improvement of PEO coatings and the optimization of their surface aspects are of major importance. In this current work, the influence of dual PEO coating on strip-cast AZ31 Mg alloy substrate has been evaluated with the aim of improving the surface and corrosion protection aspects. For this purpose, AZ31 Mg substrates are subjected to single and dual PEO processing in silicate and phosphate electrolyte under similar condition. Scanning electron microscopy (SEM) analysis confirmed that the number of pores in PEO coating processed in silicate electrolyte is higher than others. X-ray diffraction analysis of PEO coatings showed that the surface coating is mainly comprised of Mg 2 SiO 4 , Mg 3 (PO 4 ) 2 and MgO with different quantity based on PEO processing. Compared with the AZ31 Mg, the corrosion potential (E corr ) of both type PEO coatings was positively shifted about 250–400 mV and the corrosion current density (i corr ) was lowered by 3-4 orders of magnitude as result of adequate corrosion protection to the Mg alloy in 3.5% NaCl solution. All of the observation obviously showed that the dual PEO coating provides better corrosion protection performance than their respective single due to its synergistic beneficial effect. - Highlights: • Influence of dual PEO coating on AZ31 Mg alloy substrate was evaluated. • XRD confirmed formation of thin MgO inner, Mg 3 (PO 4 ) 2 and Mg 2 SiO 4 outer layer. • SEM results showed uniform coating with no cracks and relatively less micro pores. • Micro hardness of dual PEO coatings is higher than single PEO coatings. • Dual coating provides superior corrosion performance due to its synergistic effect

  18. Self-cleaning performance of superhydrophobic hybrid nanocomposite coatings on Al with excellent corrosion resistance

    International Nuclear Information System (INIS)

    Raj, V.; Mohan Raj, R.

    2016-01-01

    Highlights: • Ceramic-poly(Ani-co-oPD) coatings were formed on Al by anodization and electro-polymerisation techniques. • The superhydrophobic coating was fabricated on copolymer by electrodeposition of zinc stearate. • The superhydrophobicity mechanism relies on morphologies and chemical components on surface is the key factor. • Ceramic-poly(Ani-co-oPD)-zinc stearate coated Al has excellent corrosion resistance and good self-cleaning performance. - Abstract: Protective ceramic-PANI, ceramic-poly(Ani-co-oPD) and ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coatings were formed on Al surface by the processes involving anodization, electropolymerisation and electrodeposition under optimum conditions. The prepared nanocomposite coatings were evaluated by ATR-IR and XRD studies. SEM studies performed on nanocomposite coatings reveal that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating shows a cauliflower-like cluster with crack-free morphology compared to ceramic-PANI and ceramic-poly(Ani-co-oPD) nanocomposite coatings. The mechanical properties of different nanocomposite coatings were measured using Vicker microhardness tester and Taber Abrasion tester. The ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite has higher mechanical stability. The corrosion resistance of the coatings measured by Tafel polarization and electrochemical impedance spectroscopy, shows that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coated aluminum has higher corrosion resistance than other coatings and bare Al. Wettability studies prove that superhydrophobic nature of ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating with contact angle of 155.8° is responsible for good self-cleaning property and excellent corrosion resistance of aluminum.

  19. Self-cleaning performance of superhydrophobic hybrid nanocomposite coatings on Al with excellent corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Raj, V., E-mail: alaguraj2@rediffmail.com; Mohan Raj, R., E-mail: chem_mohan@rediffmail.com

    2016-12-15

    Highlights: • Ceramic-poly(Ani-co-oPD) coatings were formed on Al by anodization and electro-polymerisation techniques. • The superhydrophobic coating was fabricated on copolymer by electrodeposition of zinc stearate. • The superhydrophobicity mechanism relies on morphologies and chemical components on surface is the key factor. • Ceramic-poly(Ani-co-oPD)-zinc stearate coated Al has excellent corrosion resistance and good self-cleaning performance. - Abstract: Protective ceramic-PANI, ceramic-poly(Ani-co-oPD) and ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coatings were formed on Al surface by the processes involving anodization, electropolymerisation and electrodeposition under optimum conditions. The prepared nanocomposite coatings were evaluated by ATR-IR and XRD studies. SEM studies performed on nanocomposite coatings reveal that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating shows a cauliflower-like cluster with crack-free morphology compared to ceramic-PANI and ceramic-poly(Ani-co-oPD) nanocomposite coatings. The mechanical properties of different nanocomposite coatings were measured using Vicker microhardness tester and Taber Abrasion tester. The ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite has higher mechanical stability. The corrosion resistance of the coatings measured by Tafel polarization and electrochemical impedance spectroscopy, shows that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coated aluminum has higher corrosion resistance than other coatings and bare Al. Wettability studies prove that superhydrophobic nature of ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating with contact angle of 155.8° is responsible for good self-cleaning property and excellent corrosion resistance of aluminum.

  20. Quality control of thermal spray coatings in diesel engines; Qualitaetskontrolle an thermisch gespritzten Beschichtungen in Dieselmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Carstensen, Jesper Vejloe [MAN Diesel and Turbo, Copenhagen (Denmark). Material Technology and Research Dept.; Lindegren, Maria [Struers A/S, Ballerup (Denmark). Application Dept.

    2013-06-01

    Thermal spraying is a method, which is suitable for coating of large components. The coatings can e.g. improve the wear, friction and/or corrosion properties of components so that they can withstand the increased loads. The quality of the coatings is essential to ensure reliable operation of the components. However, quality control of thermally sprayed coatings is indeed nontrivial and sample preparation is a key issue. This paper shows examples of thermal spray coated components in large diesel engines and provides insight into the methods used in preparing samples for quality control. (orig.)

  1. Performance of MHD coatings in flowing Li at 700 deg

    International Nuclear Information System (INIS)

    Pint, B.; Pawel, S.J.; Howell, M.; Moser, J.L.; Garner, G.W.; Santella, M.L.; Tortorelli, P.F.; Di Stefano, J.R.

    2007-01-01

    Full text of publication follows: A thermal convection loop was constructed from V-4Cr-4Ti tubing and operated in vacuum at a maximum Li temperature of 700 deg. C for ∼1000 h.. Due to slow Li flow (∼1 cm/s) in the loop, the temperature gradient was ∼340 deg. C. Specimens in the hot and cold legs of the loop included V-4Cr-4Ti spacers, tensile specimens (SS-3 type) and coupons coated by physical vapor deposition with yttria and over coated with unalloyed vanadium. Based on prior work, the multi-layer electrically-insulating coatings were developed to reduce the magneto hydrodynamic (MHD) force expected in the first wall of a lithium cooled blanket in a magnetic confinement fusion reactor. Characterization of the specimens after exposure will include: (1) mass change and chemistry change as a function of location in the temperature gradient, (2) the effect of Li exposure on the tensile properties of V-4Cr-4Ti and (3) characterization of the properties and microstructure of the coatings after exposure. Of particular interest will be the coating resistivity after exposure and any degradation of the thin (∼10 μm) vanadium overlayer. Chemistry of the Li before and after the experiment will be compared in order to assess any mass transfer effects. (authors)

  2. Corrosion performance of some titanium-based hard coatings

    International Nuclear Information System (INIS)

    Matthes, B.; Broszeit, E.; Aromaa, J.; Ronkainen, H.; Hannula, S.P.; Leyland, A.; Matthews, A.

    1991-01-01

    Tools and machine parts which could benefit from wear-resistant titanium-based hard films are often subject to corrosive environments. Physically vapour-deposited coatings frequently exhibit porosity and even small defects, which can cause rapid local corrosion of the substrate material; there is therefore a requirement for dense and chemically inert coatings. This paper presents corrosion data for titanium-based hard coatings such as TiN, (Ti, Al)N, Ti(B, N) and TiB 2 and also for multilayered structures where additional aluminium-based insulating surface layers (AlN and Al 2 O 3 ) were deposited. The corrosion resistance and porosity of the films were analysed by electrochemical techniques. The degree of metallic bonding can play a significant role in influencing the corrosion resistance of refractory transition-metal-based ceramic coatings. Here we demonstrate that, under potentiodynamic corrosion test conditions, resistance to corrosive attack was relatively poor for TiB 2 , better for (Ti, Al)N and Ti(B, N) and best for TiN. It is also shown that applying the additional protective aluminium-based insulating surface layers on the coating can further improve corrosion resistance. (orig.)

  3. Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

    Directory of Open Access Journals (Sweden)

    Fang Luo

    2015-03-01

    Full Text Available Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

  4. Study of silica coatings degradation under laser irradiation and in controlled environment

    International Nuclear Information System (INIS)

    Becker, S.

    2006-11-01

    Performances of optical components submitted to high laser intensities are usually determined by their laser-induced damage threshold. This value represents the highest density of energy (fluence) sustainable by the component before its damage. When submitted to laser fluences far below this threshold, optical performances may also decrease with time. The degradation processes depend on laser characteristics, optical materials, and environment around the component. Silica being the most used material in optics, the aim of this study was to describe and analyse the physical-chemical mechanisms responsible for laser-induced degradation of silica coatings in controlled environment. Experimental results show that degradation is due to the growth of a carbon deposit in the irradiated zone. From these results, a phenomenological model has been proposed and validated with numerical simulations. Then, several technological solutions have been tested in order to reduce the laser-induced contamination of silica coatings. (author)

  5. Life assessment of PVD based hard coatings by linear sweep voltammetry for high performance industrial application

    International Nuclear Information System (INIS)

    Malik, M.; Alam, S.; Irfan, M.; Hassan, Z.

    2006-01-01

    PVD based hard coatings have remarkable achievements in order to improve Tribological and surface properties of coating tools and dies. As PVD based hard coatings have a wide range of industrial applications especially in aerospace and automobile parts where they met different chemical attacks and in order to improve industrial performance these coatings must provide an excellent resistance against corrosion, high temperature oxidation and chemical reaction. This paper focuses on study of behaviour of PVD based hard coatings under different corrosive environments like as H/sub 2/SO/sub 4/, HCl, NaCl, KCl, NaOH etc. Corrosion rate was calculate under linear sweep voltammetry method where the Tafel extrapolation curves used for continuously monitoring the corrosion rate. The results show that these coatings have an excellent resistance against chemical attack. (author)

  6. High-Performance Molybdenum Coating by Wire–HVOF Thermal Spray Process

    Science.gov (United States)

    Tailor, Satish; Modi, Ankur; Modi, S. C.

    2018-04-01

    Coating deposition on many industrial components with good microstructural, mechanical properties, and better wear resistance is always a challenge for the thermal spray community. A number of thermal spray methods are used to develop such promising coatings for many industrial applications, viz. arc spray, flame spray, plasma, and HVOF. All these processes have their own limitations to achieve porous free, very dense, high-performance wear-resistant coatings. In this work, an attempt has been made to overcome this limitation. Molybdenum coatings were deposited on low-carbon steel substrates using wire-high-velocity oxy-fuel (W-HVOF; WH) thermal spray system (trade name HIJET 9610®). For a comparison, Mo coatings were also fabricated by arc spray, flame spray, plasma spray, and powder-HVOF processes. As-sprayed coatings were analyzed using x-ray diffraction, scanning electron microscopy for phase, and microstructural analysis, respectively. Coating microhardness, surface roughness, and porosity were also measured. Adhesion strength and wear tests were conducted to determine the mechanical and wear properties of the as-sprayed coatings. Results show that the coatings deposited by W-HVOF have better performance in terms of microstructural, mechanical, and wear resistance properties, in comparison with available thermal spray process (flame spray and plasma spray).

  7. Scope of work for evaluating the mechanical performance of EPR first wall coatings

    International Nuclear Information System (INIS)

    Jones, W.B.; Van Den Avyle, J.A.

    1978-01-01

    An outline is presented for a proposed scope of work to evaluate the mechanical performance of candidate first wall coatings for a Tokamak-type fusion reactor. The goal of the overall program is to provide an adequate coating material and recoating process which can be manufactured by currently available vendors

  8. Lithium Surface Coatings for Improved Plasma Performance in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, H W; Ahn, J -W; Allain, J P; Bell, R; Boedo, J; Bush, C; Gates, D; Gray, T; Kaye, S; Kaita, R; LeBlanc, B; Maingi, R; Majeski, R; Mansfield, D; Menard, J; Mueller, D; Ono, M; Paul, S; Raman, R; Roquemore, A L; Ross, P W; Sabbagh, S; Schneider, H; Skinner, C H; Soukhanovskii, V; Stevenson, T; Timberlake, J; Wampler, W R

    2008-02-19

    NSTX high-power divertor plasma experiments have shown, for the first time, significant and frequent benefits from lithium coatings applied to plasma facing components. Lithium pellet injection on NSTX introduced lithium pellets with masses 1 to 5 mg via He discharges. Lithium coatings have also been applied with an oven that directed a collimated stream of lithium vapor toward the graphite tiles of the lower center stack and divertor. Lithium depositions from a few mg to 1 g have been applied between discharges. Benefits from the lithium coating were sometimes, but not always seen. These improvements sometimes included decreases plasma density, inductive flux consumption, and ELM frequency, and increases in electron temperature, ion temperature, energy confinement and periods of MHD quiescence. In addition, reductions in lower divertor D, C, and O luminosity were measured.

  9. Study on performance of waterborne anticorrosive coatings on steel rebars

    Science.gov (United States)

    Ramaswamy, S. N.; Varalakshmi, R.; Selvaraj, R.

    2017-12-01

    Durability of reinforced cement concrete structures is mainly affected by corrosion of steel reinforcements. In order to protect the reinforcing bars from corrosion and to enhance the lifetime of reinforced cement concrete structural members, anticorrosive treatment to steel is of prime importance. Conventional coatings are solvent based. In this study, water based Latex was used to formulate anticorrosive coating. Latex is applied to steel specimen substrates such as plates and rods and their mechanical properties such as flexibility, abrasion, bendability, adhesive strength, impact resistance, etc. were studied. It was inferred that coating containing latex, micro silica, zinc phosphate, ferric oxide, aluminum oxide, titanium oxide and silica fume was found to possess more corrosion resistance under marine exposure conditions.

  10. Performance of a dual-process PVD/PS tungsten coating structure under deuterium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunmyung; Lee, Ho Jung; Kim, Sung Hwan [Department of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Song, Jae-Min [Department of Nuclear Engineering, Seoul National University, Seoul (Korea, Republic of); Jang, Changheui, E-mail: chjang@kaist.ac.kr [Department of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of)

    2016-11-01

    Highlights: • D{sup +} irradiation performance of a dual-process PVD/PS W coating was evaluated. • Low-energy plasmas exposure of 100 eV D{sup +} with 1.17 × 10{sup 21} D/s{sup −1} m{sup 2} flux was applied. • After D ion irradiation, flakes were observed on the surface of the simple PS coating. • While, sub-μm size protrusions were observed for dual-process PVD/PS W coating. • Height of D spike in depth profile was lower for dual-process PVD/PS W coating. - Abstract: A dual-process coating structure was developed on a graphite substrate to improve the performance of the coating structure under anticipated operating condition of fusion devices. A thin multilayer W/Mo coating (6 μm) was deposited by physical vapor deposition (PVD) method with a variation of Mo interlayer thickness on plasma spray (PS) W coating (160 μm) of a graphite substrate panel. The dual-process PVD/PS W coatings then were exposed to 3.08 × 10{sup 24} D m{sup −2} of 100 eV D ions with a flux of 1.71 × 10{sup 21} D m{sup −2} s{sup −1} in an electron cyclotron resonance (ECR) chamber. After irradiation, surface morphology and D depth profiles of the dual-process coating were analyzed and compared to those of the simple PS W coating. Both changes in surface morphology and D retention were strongly dependent on the microstructure of surface coating. Meanwhile, the existence of Mo interlayer seemed to have no significant effect on the retention of deuterium.

  11. Interface control of atomic layer deposited oxide coatings by filtered cathodic arc deposited sublayers for improved corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Härkönen, Emma, E-mail: emma.harkonen@helsinki.fi [Laboratory of Inorganic Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland); Tervakangas, Sanna; Kolehmainen, Jukka [DIARC-Technology Inc., Espoo (Finland); Díaz, Belén; Światowska, Jolanta; Maurice, Vincent; Seyeux, Antoine; Marcus, Philippe [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7075) – Chimie ParisTech (ENSCP), F-75005 Paris (France); Fenker, Martin [FEM Research Institute, Precious Metals and Metals Chemistry, D-73525 Schwäbisch Gmünd (Germany); Tóth, Lajos; Radnóczi, György [Research Centre for Natural Sciences HAS, (MTA TKK), Budapest (Hungary); Ritala, Mikko [Laboratory of Inorganic Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland)

    2014-10-15

    Sublayers grown with filtered cathodic arc deposition (FCAD) were added under atomic layer deposited (ALD) oxide coatings for interface control and improved corrosion protection of low alloy steel. The FCAD sublayer was either Ta:O or Cr:O–Ta:O nanolaminate, and the ALD layer was Al{sub 2}O{sub 3}–Ta{sub 2}O{sub 5} nanolaminate, Al{sub x}Ta{sub y}O{sub z} mixture or graded mixture. The total thicknesses of the FCAD/ALD duplex coatings were between 65 and 120 nm. Thorough analysis of the coatings was conducted to gain insight into the influence of the FCAD sublayer on the overall coating performance. Similar characteristics as with single FCAD and ALD coatings on steel were found in the morphology and composition of the duplex coatings. However, the FCAD process allowed better control of the interface with the steel by reducing the native oxide and preventing its regrowth during the initial stages of the ALD process. Residual hydrocarbon impurities were buried in the interface between the FCAD layer and steel. This enabled growth of ALD layers with improved electrochemical sealing properties, inhibiting the development of localized corrosion by pitting during immersion in acidic NaCl and enhancing durability in neutral salt spray testing. - Highlights: • Corrosion protection properties of ALD coatings were improved by FCAD sublayers. • The FCAD sublayer enabled control of the coating-substrate interface. • The duplex coatings offered improved sealing properties and durability in NSS. • The protective properties were maintained during immersion in a corrosive solution. • The improvements were due to a more ideal ALD growth on the homogeneous FCAD oxide.

  12. Facile morphology-controlled synthesis of nickel-coated graphite core-shell particles for excellent conducting performance of polymer-matrix composites and enhanced catalytic reduction of 4-nitrophenol

    Science.gov (United States)

    Bian, Juan; Lan, Fang; Wang, Yilong; Ren, Ke; Zhao, Suling; Li, Wei; Chen, Zhihong; Li, Jiangyu; Guan, Jianguo

    2018-04-01

    We have developed a novel seed-mediated growth method to fabricate nickel-coated graphite composite particles (GP@Ni-CPs) with controllable shell morphology by simply adjusting the concentration of sodium hydroxide ([NaOH]). The fabrication of two kinds of typical GP@Ni-CPs includes adsorption of Ni2+ via electrostatic attraction, sufficient heterogeneous nucleation of Ni atoms by an in situ reduction, and shell-controlled growth by regulating the kinetics of electroless Ni plating in turn. High [NaOH] results in fast kinetics of electroless plating, which causes heterogeneous nuclei to grow isotropically. After fast and uniform growth of Ni nuclei, GP@Ni-CPs with dense shells can be achieved. The first typical GP@Ni-CPs exhibit denser shells, smaller diameters and higher conductivities than the available commercial ones, indicating their important applications in the conducting of polymer-matrix composites. On the other hand, low [NaOH] favors slow kinetics. Thus, the reduction rate of Ni2+ slows down to a relatively low level so that electroless plating is dominated thermodynamically instead of kinetically, leading to an anisotropic crystalline growth of nuclei and finally to the formation of GP@Ni-CPs with nanoneedle-like shells. The second typical samples can effectively catalyze the reduction of p-nitrophenol into p-aminophenol with NaBH4 in comparison with commercial GP@Ni-CPs and RANEY® Ni, owing to the strong charge accumulation effect of needle-like Ni shells. This work proposes a model system for fundamental investigations and has important applications in the fields of electronic interconnection and catalysis.

  13. Performance characterization of metallic substrates coated by HVOF WC–Co

    International Nuclear Information System (INIS)

    Venter, Andrew M.; Oladijo, O. Philip; Luzin, Vladimir; Cornish, Lesley A.; Sacks, Natasha

    2013-01-01

    Integral to the performance of high-velocity oxygen-fuel (HVOF) coatings is the thermo-mechanical interaction associated with the thermal misfit, or differences in thermal expansion coefficients (CTEs), between coating and substrate. This investigation reports results on the microstructures, chemical phase content, coating–substrate misfit residual stress, and wear resistance. For this purpose a systematic characterization of WC–Co sprayed coatings on a number of substrates covering a range of CTE values were pursued for both the as-coated and heat-treated conditions. The neutron diffraction technique in conjunction with sub-millimeter sized gauge volumes enabled depth-resolved studies of the stress in the coatings and substrates by paying special attention to the determination of the stress contribution attributed by the final spray process. In the as-coated condition the stress values in the coatings were compressive for CTEs larger than that of WC–Co and tensile for CTE lower than WC–Co. Wear resistance increased for increased compressive stress and macrohardness. In the heat-treated condition, this trend became enhanced due to increased compressive stress in the coatings. - Highlights: • Four different substrate systems coated with HVOF WC-Co has been investigated. • Each substrate set encompassed the grit-blast surface and as-coated conditions, as well as their heat-treated counterparts. • Microstructural, macrohardness, wear performance and depth-resolved residual stress characterised. • Successful application of neutron strain scanning to investigating the combined systems, coatings and substrates. • Link observed between macrohardness, residual stress and wear performance

  14. Fire Propagation Performance of Intumescent Fire Protective Coatings Using Eggshells as a Novel Biofiller

    Directory of Open Access Journals (Sweden)

    M. C. Yew

    2014-01-01

    Full Text Available This paper aims to synthesize and characterize an effective intumescent fire protective coating that incorporates eggshell powder as a novel biofiller. The performances of thermal stability, char formation, fire propagation, water resistance, and adhesion strength of coatings have been evaluated. A few intumescent flame-retardant coatings based on these three ecofriendly fire retardant additives ammonium polyphosphate phase II, pentaerythritol and melamine mixed together with flame-retardant fillers, and acrylic binder have been prepared and designed for steel. The fire performance of the coatings has conducted employing BS 476: Part 6-Fire propagation test. The foam structures of the intumescent coatings have been observed using field emission scanning electron microscopy. On exposure, the coated specimens’ B, C, and D had been certified to be Class 0 due to the fact that their fire propagation indexes were less than 12. Incorporation of ecofriendly eggshell, biofiller into formulation D led to excellent performance in fire stopping (index value, (I=4.3 and antioxidation of intumescent coating. The coating is also found to be quite effective in water repellency, uniform foam structure, and adhesion strength.

  15. Reproductive performance of breeder quails fed diets supplemented with L-cysteine-coated iron oxide nanoparticles.

    Science.gov (United States)

    Mohammadi, H; Farzinpour, A; Vaziry, A

    2017-04-01

    The objective of this study was to investigate the effects of L-cysteine-coated iron oxide nanoparticles on reproductive performance in breeder quails. The five treatment diets consisted of (i) negative control diet not supplemented with iron, (ii) positive control diet supplemented with 60 mg/kg of Fe 3 O 4 and (iii) experimental diets supplemented with 0.6, 6 and 60 mg/kg of L-cysteine-coated iron oxide nanoparticles. A total of 100 seven-day-old quail chicks were weighed and randomly placed to five groups of five replicate cages. Four quails (one male and three females) were raised in each cage (50 × 15 × 17 cm). Egg production, feed consumption and egg weight were recorded daily and calculated on a hen per day basis. Egg components, fertility, hatchability and day-old chicks hatched from their eggs were measured at the end of the experiment. The percentage of egg production and egg mass of the 6 mg/kg Fe 3 O 4 -Cys NPs group were significantly higher than those of the control groups. Throughout the experimental period, the highest weekly egg weight was recorded for the 60 mg/kg Fe 3 O 4 -Cys NPs group. Fertility was improved by diet supplemented with iron, both FeSO 4 and Fe 3 O 4 -Cys NPs. The breeder fed Fe 3 O 4 -Cys NPs had the highest day-old chicks weight. The results of this study showed that Fe 3 O 4 nanoparticles that were coated by L-cysteine could improve availability and utilization of iron in diet. Finally, it was proposed that Fe 3 O 4 -Cys NPs could be used as feed additives in quails. © 2017 Blackwell Verlag GmbH.

  16. Reliability of magnetic particle inspection performed through coatings: Final report

    International Nuclear Information System (INIS)

    1988-07-01

    The magnetic particle examination (MT) technique can reliably examine containment welds without removing their protective coatings. This study has investigated a variety of MT methods used in the oil and gas industry for their suitability for nuclear plant applications. 102 figs

  17. Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

    Science.gov (United States)

    Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

    As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

  18. An investigation of material properties and tribological performance of magnetron sputtered thin film coatings

    Science.gov (United States)

    Singh, Harpal

    This dissertation is divided into two categories based upon lubrication functionality and its application. The categories are: Dry film lubrication and Fluid film lubrication with thin film coatings. Thin film coatings examined in this work were deposited using closed field unbalanced magnetron sputtering and RF-DC coupled magnetron sputtering systems. In Dry/Solid film lubrication, the mechanical, structural and tribological properties of two Molybdenum disulphide (MoS2) based coatings are examined and evaluated. Among the two coatings, one coating is doped with Ti (Ti-MoS2) and the other is a combination of metal, lubricant and oxide (Sb2O3/Au - MoS2). These coatings are known to provide low friction in vacuum environments. The goal of this work was to evaluate friction and wear performance of MoS2 doped coatings in unidirectional and reciprocating sliding contact under different environmental conditions. Sliding contact results showed friction and wear dependence on temperature and humidity. The formation and removal of transfer films and the recrystallization and reorientation of basal layers on the steel counterface was observed as the mechanism for low friction. Structural analysis revealed a relationship between the microstructural properties and tribological performance. It was also observed that the addition of dopants (Ti, Au, Sb 2O3) improved the mechanical properties as compared to pure MoS2 coatings. Further, the rolling contact performance of the coatings was measured on a five ball on rod tribometer and a Thrust bearing tribometer under vacuum and air environments. The rolling contact experiments indicated that life of the rolling components depend on the amount of material present between the contacts. Fluid film lubrication with thin film coatings investigates the possibilities to improve the performance and durability of tribological components when oils and thin films are synergistically coupled. In this work, the ability of a Diamond Like Carbon

  19. Improved dental implant drill durability and performance using heat and wear resistant protective coatings.

    Science.gov (United States)

    Er, Nilay; Alkan, Alper; İlday, Serim; Bengu, Erman

    2018-03-02

    Dental implant drilling procedure is an essential step for implant surgery and frictional heat appeared in bone during drilling is a key factor affecting the success of an implant. The aim of this study is to increase the dental implant drill lifetime and performance using heat- and wear-resistant protective coatings hence to decrease the alveolar bone temperature caused by the dental implant drilling procedure. Commercially obtained stainless steel drills were coated with titanium aluminum nitride, diamond-like carbon, titanium boron nitride, and boron nitride coatings via magnetron-sputter deposition. Drilling procedure was performed on a bovine femoral cortical bone under the conditions mimicking clinical practice, where the tests were performed both under water-assisted cooling and under the conditions without any cooling was applied. Coated drill performances and durabilities were compared to that of three commonly used commercial drills which surfaces are made from namely; zirconia, black diamond and stainless steel. Protective coatings with boron nitride, titanium boron nitride and diamond-like carbon have significantly improved drill performance and durability. Especially boron nitride-coated drills have performed within safe bone temperature limits for 50 drillings even without any cooling is applied. Titanium aluminium nitride coated drills did not show any improvement over commercially obtained stainless steel drills. Surface modification using heat and wear resistant coatings is an easy and highly effective way to improve implant drill performance and durability, which can reflect positively on surgical procedure and healing period afterwards. The noteworthy success of different types of coatings is novel and likely to be applicable to various other medical systems.

  20. Impact on burnup performance of coated particle fuel design in pebble bed reactor with ROX fuel

    International Nuclear Information System (INIS)

    Ho, Hai Quan; Obara, Toru

    2015-01-01

    The pebble bed reactor (PBR), a kind of high-temperature gas-cooled reactor (HTGR), is expected to be among the next generation of nuclear reactors as it has excellent passive safety features, as well as online refueling and high thermal efficiency. Rock-like oxide (ROX) fuel has been studied at the Japan Atomic Energy Agency (JAEA) as a new once-through type fuel concept. Rock-like oxide used as fuel in a PBR can be expected to achieve high burnup and improve chemical stabilities. In the once-through fuel concept, the main challenge is to achieve as high a burnup as possible without failure of the spent fuel. The purpose of this study was to investigate the impact on burnup performance of different coated fuel particle (CFP) designs in a PBR with ROX fuel. In the study, the AGR-1 Coated Particle design and Deep-Burn Coated Particle design were used to make the burnup performance comparison. Criticality and core burnup calculations were performed by MCPBR code using the JENDL-4.0 library. Results at equilibrium showed that the two reactors utilizing AGR-1 Coated Particle and Deep-Burn Coated Particle designs could be critical with almost the same multiplication factor k eff . However, the power peaking factor and maximum power per fuel ball in the AGR-1 coated particle design was lower than that of Deep-Burn coated particle design. The AGR-1 design also showed an advantage in fissions per initial fissile atoms (FIFA); the AGR-1 coated particle design produced a higher FIFA than the Deep-Burn coated particle design. These results suggest that the difference in coated particle fuel design can have an effect on the burnup performance in ROX fuel. (author)

  1. Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool

    Directory of Open Access Journals (Sweden)

    Jose Mario Paiva

    2018-02-01

    Full Text Available In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,AlN deposited by physical vapor deposition (PVD have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC and one central rotating cathode (CERC. The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES, scanning electron microscopy (SEM, and X-ray diffraction (XRD, respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si3N4 nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

  2. Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool.

    Science.gov (United States)

    Paiva, Jose Mario; Fox-Rabinovich, German; Locks Junior, Edinei; Stolf, Pietro; Seid Ahmed, Yassmin; Matos Martins, Marcelo; Bork, Carlos; Veldhuis, Stephen

    2018-02-28

    In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,Al)N deposited by physical vapor deposition (PVD) have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel) by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC) and one central rotating cathode (CERC). The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM) and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si₃N₄ nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

  3. Artificial chameleon skin that controls spectral radiation: Development of Chameleon Cool Coating (C3).

    Science.gov (United States)

    Gonome, Hiroki; Nakamura, Masashi; Okajima, Junnosuke; Maruyama, Shigenao

    2018-01-19

    Chameleons have a diagnostic thermal protection that enables them to live under various conditions. Our developed special radiative control therefore is inspired by the chameleon thermal protection ability by imitating its two superposed layers as two pigment particles in one coating layer. One particle imitates a chameleon superficial surface for color control (visible light), and another particle imitates a deep surface to reflect solar irradiation, especially in the near-infrared region. Optical modeling allows us to optimally design the particle size and volume fraction. Experimental evaluation shows that the desired spectral reflectance, i.e., low in the VIS region and high in NIR region, can be achieved. Comparison between the measured and calculated reflectances shows that control of the particle size and dispersion/aggregation of particle cloud is important in improving the thermal-protection performance of the coating. Using our developed coating, the interior temperature decreases and the cooling load is reduced while keeping the dark tone of the object.

  4. Al2O3-coated porous separator for enhanced electrochemical performance of lithium sulfur batteries

    International Nuclear Information System (INIS)

    Zhang, Zhiyong; Lai, Yanqing; Zhang, Zhian; Zhang, Kai; Li, Jie

    2014-01-01

    Graphical abstract: Al2O3-coated separator with developed porous channels is prepared by coating Al2O3 polymer solution on routine separator. The batteries with Al2O3-coated separator exhibited a reversible capacity of as high as 593 mAh g-1 at the rate of 0.2 C after 50th charge/discharge cycle. The enhancement in the electrochemical performance could be attributed to the reduced charge transfer resistance after the introduction of Al2O3 coating layer. Besides, the Al2O3 coating layer, acting as a physical barrier for polysulfides, can effectively prevent polysulfides shuttling between the cathode and the anode. We believe that the Al2O3-coated separator is promising in the lithium sulfur battery applications. - Highlights: • Al 2 O 3 -coated separator is used as the separator of lithium sulfur battery. • The cell with Al 2 O 3 -coated separator exhibits excellent cycling stability and high rate capability. • Al 2 O 3 -coated separator is promising in the lithium sulfur battery applications. - Abstract: In this paper, Al 2 O 3 -coated separator with developed porous channels is prepared to improve the electrochemical performance of lithium sulfur batteries. It is demonstrated that the Al 2 O 3 -coating layer is quite effective in reducing shuttle effect and enhancing the stability of the sulfur electrode. The initial discharge capacity of the cell with Al 2 O 3 -coated separator can reach 967 mAh g −1 at the rate of 0.2 C. After 50th charge/discharge cycle, this cell can also deliver a reversible capacity of as high as 593.4 mAh g −1 . Significantly, the charge-transfer resistance of the electrode tends to be reducing after using Al 2 O 3 -coated separator. The improved cell performance is attributed to the porous architecture of the Al 2 O 3 -coating layer, which serves as an ion-conducting skeleton for trapping and depositing dissolved sulfur-containing active materials, as confirmed by scanning electron microscopy (SEM) and energy-dispersive X

  5. Environmental Barrier Coatings for Turbine Engines: A Design and Performance Perspective

    Science.gov (United States)

    Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis; Smialek, James L.; Miller, Robert A.

    2009-01-01

    Ceramic thermal and environmental barrier coatings (TEBC) for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating long-term durability remains a major concern with the ever-increasing temperature, strength and stability requirements in engine high heat-flux combustion environments, especially for highly-loaded rotating turbine components. Advanced TEBC systems, including nano-composite based HfO2-aluminosilicate and rare earth silicate coatings are being developed and tested for higher temperature capable SiC/SiC ceramic matrix composite (CMC) turbine blade applications. This paper will emphasize coating composite and multilayer design approach and the resulting performance and durability in simulated engine high heat-flux, high stress and high pressure combustion environments. The advances in the environmental barrier coating development showed promise for future rotating CMC blade applications.

  6. Precise Morphology Control and Continuous Fabrication of Perovskite Solar Cells Using Droplet-Controllable Electrospray Coating System.

    Science.gov (United States)

    Hong, Seung Chan; Lee, Gunhee; Ha, Kyungyeon; Yoon, Jungjin; Ahn, Namyoung; Cho, Woohyung; Park, Mincheol; Choi, Mansoo

    2017-03-08

    Herein, we developed a novel electrospray coating system for continuous fabrication of perovskite solar cells with high performance. Our system can systemically control the size of CH 3 NH 3 PbI 3 precursor droplets by modulating the applied electrical potential, shown to be a crucial factor for the formation of perovskite films. As a result, we have obtained pinhole-free and large grain-sized perovskite solar cells, yielding the best PCE of 13.27% with little photocurrent hysteresis. Furthermore, the average PCE through the continuous coating process was 11.56 ± 0.52%. Our system demonstrates not only the high reproducibility but also a new way to commercialize high-quality perovskite solar cells.

  7. 49 CFR 195.559 - What coating material may I use for external corrosion control?

    Science.gov (United States)

    2010-10-01

    ...) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.559 What coating... 49 Transportation 3 2010-10-01 2010-10-01 false What coating material may I use for external corrosion control? 195.559 Section 195.559 Transportation Other Regulations Relating to Transportation...

  8. Design and development on automated control system of coated fuel particle fabrication process

    International Nuclear Information System (INIS)

    Liu Malin; Shao Youlin; Liu Bing

    2013-01-01

    With the development trend of the large-scale production of the HTR coated fuel particles, the original manual control system can not meet the requirement and the automation control system of coated fuel particle fabrication in modern industrial grade is needed to develop. The comprehensive analysis aiming at successive 4-layer coating process of TRISO type coated fuel particles was carried out. It was found that the coating process could be divided into five subsystems and nine operating states. The establishment of DCS-type (distributed control system) of automation control system was proposed. According to the rigorous requirements of preparation process for coated particles, the design considerations of DCS were proposed, including the principle of coordinated control, safety and reliability, integration specification, practical and easy to use, and open and easy to update. A complete set of automation control system for coated fuel particle preparation process was manufactured based on fulfilling the requirements of these principles in manufacture practice. The automated control system was put into operation in the production of irradiated samples for HTRPM demonstration project. The experimental results prove that the system can achieve better control of coated fuel particle preparation process and meet the requirements of factory-scale production. (authors)

  9. Promising Hard Carbon Coatings on Cu Substrates: Corrosion and Tribological Performance with Theoretical Aspect

    Science.gov (United States)

    Kumar, A. Madhan; Babu, R. Suresh; Obot, I. B.; Adesina, Akeem Yusuf; Ibrahim, Ahmed; de Barros, A. L. F.

    2018-05-01

    Protecting the surface of metals and alloys against corrosion and wear is of abundant importance owing to their widespread applications. In the present work, we report the improved anticorrosion and tribo-mechanical performance of copper (Cu) by a hard carbon (HC) coating synthesized in different pyrolysis temperature. Structural and surface characterization with roughness measurements was systematically investigated using various techniques. Effect of pyrolysis temperature on the corrosion behavior of coated Cu substrates in 0.6 M NaCl solution was evaluated via electrochemical impedance spectroscopy, potentiodynamic polarization. Pin-on-disk wear test of coated Cu substrate showed the influence of the pyrolysis temperature on the wear resistance performance of the HC coatings. According to the obtained results, it could be concluded that the HC coatings synthesized at 1100 °C revealed an enhanced comprehensive performance, revealing their possible utilization as a protective coating for Cu substrates in chloride environment. Monte Carlo simulations have been utilized to elucidate the interaction between the Cu surface and HC coatings.

  10. Electrochemical performances of diamond-like carbon coatings on carbon steel, stainless steel, and brass

    International Nuclear Information System (INIS)

    Hadinata, Samuel-Sudibyo; Lee, Ming-Tsung; Pan, Szu-Jung; Tsai, Wen-Ta; Tai, Chen-Yi; Shih, Chuan-Feng

    2013-01-01

    Diamond-like carbon (DLC) coatings have been deposited onto stainless steel, carbon steel and brass by plasma-enhanced chemical vapor deposition, respectively. Atomic arrangement, chemical structure, surface morphology and cross-section microstructure of the DLC coatings were examined by X-ray diffraction, Raman scattering spectroscopy and scanning electron microscopy. The electrochemical behaviors of the DLC coatings in 3.5 wt.% NaCl solution were investigated by performing an open circuit potential (OCP) measurement and a potentiodynamic polarization test. The experimental results showed that properly deposited DLC coatings could cause an increase of OCP by hundreds of millivolts and a reduction of anodic current density by several orders of magnitude as compared to that of the substrate. The results also demonstrated that electrochemical techniques could be used as tools to detect the soundness of the DLC coating by examining OCP and polarization curve, which varied with the form of defect and depended on the type of substrate. - Highlights: ► The substrate could affect the quality of diamond-like carbon (DLC) coating. ► Defect-free DLC coating exhibited extremely low anodic current density. ► The quality of DLC coating on metal could be evaluated by electrochemical test

  11. Electrochemical performances of diamond-like carbon coatings on carbon steel, stainless steel, and brass

    Energy Technology Data Exchange (ETDEWEB)

    Hadinata, Samuel-Sudibyo; Lee, Ming-Tsung [Department of Materials Science and Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Pan, Szu-Jung [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Tsai, Wen-Ta, E-mail: wttsai@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Tai, Chen-Yi [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Shih, Chuan-Feng [Ocean Energy Research Center, Tainan Hydraulics Laboratory, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China); Department of Electrical Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan (China)

    2013-02-01

    Diamond-like carbon (DLC) coatings have been deposited onto stainless steel, carbon steel and brass by plasma-enhanced chemical vapor deposition, respectively. Atomic arrangement, chemical structure, surface morphology and cross-section microstructure of the DLC coatings were examined by X-ray diffraction, Raman scattering spectroscopy and scanning electron microscopy. The electrochemical behaviors of the DLC coatings in 3.5 wt.% NaCl solution were investigated by performing an open circuit potential (OCP) measurement and a potentiodynamic polarization test. The experimental results showed that properly deposited DLC coatings could cause an increase of OCP by hundreds of millivolts and a reduction of anodic current density by several orders of magnitude as compared to that of the substrate. The results also demonstrated that electrochemical techniques could be used as tools to detect the soundness of the DLC coating by examining OCP and polarization curve, which varied with the form of defect and depended on the type of substrate. - Highlights: ► The substrate could affect the quality of diamond-like carbon (DLC) coating. ► Defect-free DLC coating exhibited extremely low anodic current density. ► The quality of DLC coating on metal could be evaluated by electrochemical test.

  12. Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

    Energy Technology Data Exchange (ETDEWEB)

    Rojaee, Ramin, E-mail: raminrojaee@aim.com [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

    2013-10-15

    Magnesium (Mg) alloys have been introduced as new generation of biodegradable orthopedic materials in recent years since it has been proved that Mg is one of the main minerals required for osseous tissue revival. The main goal of the present study was to establish a desired harmony between the necessities of orthopedic patient body to Mg{sup 2+} ions and degradation rate of the Mg based implants as a new class of biodegradable/bioresorbable materials. This prospect was followed by providing a sol–gel derived nanostructured hydroxyapatite (n-HAp) coating on AZ91 alloy using dip coating technique. Phase structural analysis, morphology study, microstructure characterization, and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The prepared samples were immersed in simulated body fluid in order to study the formation of apatite-like precipitations, barricade properties of the n-HAp coating, and to estimate the dosage of released Mg{sup 2+} ions within a specified and limited time of implantation. Electrochemical polarization tests were carried out to evaluate and compare the corrosion behavior of the n-HAp coated and uncoated samples. The changes of the in vitro pH values were also evaluated. Results posed the noticeable capability of n-HAp coating on stabilizing alkalization behavior and improving the corrosion resistance of AZ91 alloy. It was concluded that n-HAp coated AZ91 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. - Highlights: • Nanostructured hydroxyapatite coatings were applied on Mg based alloy. • The whole corrosion process of Mg based alloy was controlled in body fluid. • This coating was able to act as a barrier against further release of Mg{sup 2+} ions. • The coating improved the stabilization of Mg alkalization behavior.

  13. Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

    International Nuclear Information System (INIS)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-01-01

    Magnesium (Mg) alloys have been introduced as new generation of biodegradable orthopedic materials in recent years since it has been proved that Mg is one of the main minerals required for osseous tissue revival. The main goal of the present study was to establish a desired harmony between the necessities of orthopedic patient body to Mg 2+ ions and degradation rate of the Mg based implants as a new class of biodegradable/bioresorbable materials. This prospect was followed by providing a sol–gel derived nanostructured hydroxyapatite (n-HAp) coating on AZ91 alloy using dip coating technique. Phase structural analysis, morphology study, microstructure characterization, and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The prepared samples were immersed in simulated body fluid in order to study the formation of apatite-like precipitations, barricade properties of the n-HAp coating, and to estimate the dosage of released Mg 2+ ions within a specified and limited time of implantation. Electrochemical polarization tests were carried out to evaluate and compare the corrosion behavior of the n-HAp coated and uncoated samples. The changes of the in vitro pH values were also evaluated. Results posed the noticeable capability of n-HAp coating on stabilizing alkalization behavior and improving the corrosion resistance of AZ91 alloy. It was concluded that n-HAp coated AZ91 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. - Highlights: • Nanostructured hydroxyapatite coatings were applied on Mg based alloy. • The whole corrosion process of Mg based alloy was controlled in body fluid. • This coating was able to act as a barrier against further release of Mg 2+ ions. • The coating improved the stabilization of Mg alkalization behavior

  14. Quantitative fabrication, performance optimization and comparison of PEG and zwitterionic polymer antifouling coatings.

    Science.gov (United States)

    Xing, Cheng-Mei; Meng, Fan-Ning; Quan, Miao; Ding, Kai; Dang, Yuan; Gong, Yong-Kuan

    2017-09-01

    A versatile fabrication and performance optimization strategy of PEG and zwitterionic polymer coatings is developed on the sensor chip of surface plasma resonance (SPR) instrument. A random copolymer bearing phosphorylcholine zwitterion and active ester side chains (PMEN) and carboxylic PEG coatings with comparable thicknesses were deposited on SPR sensor chips via amidation coupling on the precoated polydopamine (PDA) intermediate layer. The PMEN coating showed much stronger resistance to bovine serum albumin (BSA) adsorption than PEG coating at very thin thickness (∼1nm). However, the BSA resistant efficacy of PEG coating could exceed that of PMEN due to stronger steric repelling effect when the thickness increased to 1.5∼3.3nm. Interestingly, both the PEG and PMEN thick coatings (≈3.6nm) showed ultralow fouling by BSA and bovine plasma fibrinogen (Fg). Moreover, changes in the PEG end group from -OH to -COOH, protein adsorption amount could increase by 10-fold. Importantly, the optimized PMEN and PEG-OH coatings were easily duplicated on other substrates due to universal adhesion of the PDA layer, showed excellent resistance to platelet, bacteria and proteins, and no significant difference in the antifouling performances was observed. These detailed results can explain the reported discrepancy in performances between PEG and zwitterionic polymer coatings by thickness. This facile and substrate-independent coating strategy may benefit the design and manufacture of advanced antifouling biomedical devices and long circulating nanocarriers. Prevention of biofouling is one of the biggest challenges for all biomedical applications. However, it is very difficult to fabricate a highly hydrophilic antifouling coating on inert materials or large devices. In this study, PEG and zwitterion polymers, the most widely investigated polymers with best antifouling performance, are conveniently immobilized on different kinds of substrates from their aqueous solutions by

  15. Influence of Experimental Parameters Using the Dip-Coating Method on the Barrier Performance of Hybrid Sol-Gel Coatings in Strong Alkaline Environments

    Directory of Open Access Journals (Sweden)

    Rita B. Figueira

    2015-04-01

    Full Text Available Previous studies have shown that the barrier effect and the performance of organic-inorganic hybrid (OIH sol-gel coatings are highly dependent on the coating deposition method as well as on the processing conditions. However, studies on how the coating deposition method influences the barrier properties in alkaline environments are scarce. The aim of this experimental research was to study the influence of experimental parameters using the dip-coating method on the barrier performance of an OIH sol-gel coating in contact with simulated concrete pore solutions (SCPS. The influence of residence time (Rt, a curing step between each dip step and the number of layers of sol-gel OIH films deposited on hot-dip galvanized steel to prevent corrosion in highly alkaline environments was studied. The barrier performance of these OIH sol-gel coatings, named U(400, was assessed in the first instants of contact with SCPS, using electrochemical impedance spectroscopy and potentiodynamic methods. The durability and stability of the OIH coatings in SCPS was monitored during eight days by macrocell current density. The morphological characterization of the surface was performed by Scanning Electronic Microscopy before and after exposure to SCPS. Glow Discharge Optical Emission Spectroscopy was used to investigate the thickness of the U(400 sol-gel coatings as a function of the number of layers deposited with and without Rt in the coatings thickness.

  16. Mitigating SDN controller performance bottlenecks

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius; Soler, José

    2015-01-01

    The centralization of the control plane decision logic in Software Defined Networking (SDN) has raised concerns regarding the performance of the SDN Controller (SDNC) when the network scales up. A number of solutions have been proposed in the literature to address these concerns. This paper...... proposes a new approach for addressing the performance bottlenecks that arise from limited computational resources at the SDNC. The proposed approach is based on optimally configuring the operating parameters of the components residing inside the SDNC (network control functions such as monitoring, routing...

  17. Achieving Control of Coating Process in your Foundry

    DEFF Research Database (Denmark)

    Di Muoio, G. L.; Tiedje, N. S.

    2015-01-01

    process is prerequisite for a stable drying process. In this study, we analyse the effect of different variables on the coating layer properties. We start by considering four critical variables identified in a previous study such as sand compaction, coating density, dipping time and gravity and then we...

  18. Friction and wear performance of bearing ball sliding against diamond-like carbon coatings

    Science.gov (United States)

    Wu, Shenjiang; Kousaka, Hiroyuki; Kar, Satyananda; Li, Dangjuan; Su, Junhong

    2017-01-01

    We have studied the tribological properties of bearing steel ball (Japan standard, SUJ2) sliding against tetrahedral amorphous carbon (ta-C) coatings and amorphous hydrogenated carbon (a-C:H) coatings. The reciprocating sliding testes are performed with ball-on-plate friction tester in ambient air condition. Analysis of friction coefficient, wear volume and microstructure in wear scar are carried out using optical microscopy, atom force morphology (AFM) and Raman spectroscopy. The results show the SUJ2 on ta-C coating has low friction coefficient (around 0.15) but high wear loss. In contrast, the low wear loss of SUJ2 on a-C:H coating with high (around 0.4) and unsteady friction coefficient. Some Fe2O3, FeO and graphitization have been found on the wear scar of SUJ2 sliding against ta-C coating. Nearly no oxide materials exist on the wear scar of SUJ2 against a-C:H coating. The mechanism and hypothesis of the wear behavior have been investigated according to the measurement results. This study will contribute to proper selection and understand the tribological performance of bearing steels against DLC coatings.

  19. Investigation of Coating Performance of UV-Curable Hybrid Polymers Containing 1H,1H,2H,2H-Perfluorooctyltriethoxysilane Coated on Aluminum Substrates

    Directory of Open Access Journals (Sweden)

    Mustafa Çakır

    2017-03-01

    Full Text Available This study describes preparation and characterization of fluorine-containing organic-inorganic hybrid coatings. The organic part consists of bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin and 1,6-hexanediol diacrylate reactive diluent. The inorganically rich part comprises trimethoxysilane-terminated urethane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl propyl methacrylate and sol–gel precursors that are products of hydrolysis and condensation reactions. Bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin was added to the inorganic part in predetermined amounts. The resultant mixture was utilized in the preparation of free films as well as coatings on aluminum substrates. Thermal and mechanical tests such as DSC, thermo-gravimetric analysis (TGA, and tensile and shore D hardness tests were performed on free films. Water contact angle, gloss, Taber abrasion test, cross-cut and tubular impact tests were conducted on the coated samples. SEM examination and EDS analysis was performed on the fractured surfaces of free films. The hybrid coatings on the aluminum sheets gave rise to properties such as moderately glossed surface; low wear rate and hydrophobicity. Tensile strength of free films increased with up to 10% inorganic content in the hybrid structure and this increase was approximately three times that of the control sample. As expected; the % strain value decreased by 17.3 with the increase in inorganic content and elastic modulus values increased by a factor of approximately 6. Resistance to ketone-based solvents was proven and an increase in hardness was observed as the ratio of the inorganic part increased. Samples which contain 10% sol–gel content were observed to provide optimal properties.

  20. Controlled release from drug microparticles via solventless dry-polymer coating.

    Science.gov (United States)

    Capece, Maxx; Barrows, Jason; Davé, Rajesh N

    2015-04-01

    A novel solvent-less dry-polymer coating process employing high-intensity vibrations avoiding the use of liquid plasticizers, solvents, binders, and heat treatments is utilized for the purpose of controlled release. The main hypothesis is that such process having highly controllable processing intensity and time may be effective for coating particularly fine particles, 100 μm and smaller via exploiting particle interactions between polymers and substrates in the dry state, while avoiding breakage yet achieving conformal coating. The method utilizes vibratory mixing to first layer micronized polymer onto active pharmaceutical ingredient (API) particles by virtue of van der Waals forces and to subsequently mechanically deform the polymer into a continuous film. As a practical example, ascorbic acid and ibuprofen microparticles, 50-500 μm, are coated with the polymers polyethylene wax or carnauba wax, a generally recognized as safe material, resulting in controlled release on the order of seconds to hours. As a novelty, models are utilized to describe the coating layer thickness and the controlled-release behavior of the API, which occurs because of a diffusion-based mechanism. Such modeling would allow the design and control of the coating process with application for the controlled release of microparticles, particularly those less than 100 μm, which are difficult to coat by conventional solvent coating methods. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. The Role of interfacial layers on the performance of an epoxy / polyester powder coated Aluminium Alloy

    International Nuclear Information System (INIS)

    Mirabedini, M.; Moradian, S.; Scanteburg, D.; Thonpson, G.E.

    2002-01-01

    The influence of polyacrylic acid and a blend of polyacrylic acid with hexa fluorozirconic acid treatments on the performance of an epoxy/polyester powder coating on a 1050 Al substrate has been studied and compared to the performance of the same system using a so-called chromate/phosphate conversion coating. The chemical interactions between pretreatments and Al substrates were examined using FTIR spectroscopy and various accelerated test methods were also employed. Two mechanical adhesion measurement methods were used under wet and dry conditions, namely a vertical pull-off test in the dry state and the tape test under dry conditions. The water permeation of the differently pretreated powder coated samples was studied using a capacitance measurement method. FTIR results showed two modes of interaction; namely ionic and complex formation between COO - and Al 3+ Various experiments revealed that polyacrylic acid improved only the dry adhesion but as a standing alone treatment it did not provide an overall improvement in anti-corrosive performance. The water uptake measurements proved that pretreatment does not considerably affect the properties of the coatings during water permeation stage. The use of various techniques revealed that relatively good performance of powder coating is due to a high ohmic resistance of the coating prior to and after saturation with water, reasonably low water solubility and good adhesion to the substrate

  2. Improvement of Drill Performance in Metal Cutting Using MoST Solid Lubricant Coatings

    Institute of Scientific and Technical Information of China (English)

    N.R. Thomas; D.G. Teer; S. Yang; S. Hickman

    2004-01-01

    Coated tools are widely used in today's metal cutting industries and have significantly improved machining productivity through reducing operation costs and time. This paper presents the results of a systematic study of the performance of HSS drills coated with CrTiAlN and drills with a top solid lubricant coating of MoSTTM. The tests were performed on a Haas vertical machining centre under wet and dry cutting conditions to machine through holes in medium carbon steel workpieces. The feed force and torque were recorded throughout some of the tests using a force dynamometer,while the tool wear was monitored and measured. It was found that MoSTTM coatings even under accelerated conditions improve the tool life significantly based on their unique properties and very low friction.

  3. Effect of surface coating with magnesium stearate via mechanical dry powder coating approach on the aerosol performance of micronized drug powders from dry powder inhalers.

    Science.gov (United States)

    Zhou, Qi Tony; Qu, Li; Gengenbach, Thomas; Larson, Ian; Stewart, Peter J; Morton, David A V

    2013-03-01

    The objective of this study was to investigate the effect of particle surface coating with magnesium stearate on the aerosolization of dry powder inhaler formulations. Micronized salbutamol sulphate as a model drug was dry coated with magnesium stearate using a mechanofusion technique. The coating quality was characterized by X-ray photoelectron spectroscopy. Powder bulk and flow properties were assessed by bulk densities and shear cell measurements. The aerosol performance was studied by laser diffraction and supported by a twin-stage impinger. High degrees of coating coverage were achieved after mechanofusion, as measured by X-ray photoelectron spectroscopy. Concomitant significant increases occurred in powder bulk densities and in aerosol performance after coating. The apparent optimum performance corresponded with using 2% w/w magnesium stearate. In contrast, traditional blending resulted in no significant changes in either bulk or aerosolization behaviour compared to the untreated sample. It is believed that conventional low-shear blending provides insufficient energy levels to expose host micronized particle surfaces from agglomerates and to distribute guest coating material effectively for coating. A simple ultra-high-shear mechanical dry powder coating step was shown as highly effective in producing ultra-thin coatings on micronized powders and to substantially improve the powder aerosolization efficiency.

  4. Study on heat transfer performance of water-borne and oily graphene coatings using anti-/de-icing component

    Science.gov (United States)

    Chen, Long; Zhang, Yidu; Wu, Qiong; Jie, Zhang

    2018-02-01

    A graphene coating anti-/de-icing experiment was proposed by employing water-borne and oily graphene coatings on the composite material anti-/de-icing component. Considering the characteristics of helicopter rotor sensitivity to icing, a new graphene coating enhancing thermal conductivity of anti-/de-icing component was proposed. The anti-/de-icing experiment was conducted to validate the effectiveness of graphene coating. The results of the experiment show that the graphene coatings play a prominent role in controlling the heat transfer of anti-/de-icing component. The anti-/de-icing effect of oily graphene coating is superior to water-borne graphene.

  5. Control of surface topography in biomimetic calcium phosphate coatings.

    Science.gov (United States)

    Costa, Daniel O; Allo, Bedilu A; Klassen, Robert; Hutter, Jeffrey L; Dixon, S Jeffrey; Rizkalla, Amin S

    2012-02-28

    The behavior of cells responsible for bone formation, osseointegration, and bone bonding in vivo are governed by both the surface chemistry and topography of scaffold matrices. Bone-like apatite coatings represent a promising method to improve the osteoconductivity and bonding of synthetic scaffold materials to mineralized tissues for regenerative procedures in orthopedics and dentistry. Polycaprolactone (PCL) films were coated with calcium phosphates (CaP) by incubation in simulated body fluid (SBF). We investigated the effect of SBF ion concentration and soaking time on the surface properties of the resulting apatite coatings. CaP coatings were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and energy dispersive X-ray spectrometry (EDX). Young's modulus (E(s)) was determined by nanoindentation, and surface roughness was assessed by atomic force microscopy (AFM) and mechanical stylus profilometry. CaP such as carbonate-substituted apatite were deposited onto PCL films. SEM and AFM images of the apatite coatings revealed an increase in topographical complexity and surface roughness with increasing ion concentration of SBF solutions. Young's moduli (E(s)) of various CaP coatings were not significantly different, regardless of the CaP phase or surface roughness. Thus, SBF with high ion concentrations may be used to coat synthetic polymers with CaP layers of different surface topography and roughness to improve the osteoconductivity and bone-bonding ability of the scaffold. © 2012 American Chemical Society

  6. Tribological performance of hard carbon coatings on 440C bearing steel

    Energy Technology Data Exchange (ETDEWEB)

    Kustas, F M; Misra, M S; Shepard, D F; Froechtenigt, J F [Martin Marietta Astronautics Group, Denver, CO (United States)

    1991-11-01

    Hard carbon coatings such as amorphous carbon, diamond and diamond-like carbon have received considerable attention for tribological applications owing to their high hardness, high modulus and desirable surface properties. Unfortunately, most of the deposition techniques induce high substrate temperatures that would temper traditional bearing steels and reduce the substrate load-carrying capability. Therefore, to effectively use these desirable coatings, a lower temperature deposition technique is required. Ion beam deposition can provide essentially ambient temperature conditions, accurate control of process parameters and good coating-substrate adhesion. To use these attributes, a test program was initiated to deposit mass-analyzed, high purity C{sup +} and CH{sub 4}{sup +} ions on molybdenum and 440C bearing steel for subsequent characterization by Raman spectroscopy and friction-wear tests. Results for a coating deposited from a carbon monoxide source showed an amorphous carbon-microcrystalline graphtie structure which exhibited very high microhardness and a three fold reduction in coefficient of friction for unlubricated tests compared to untreated 440C steel. In addition, incrementally increasing the applied load (by up to a factor of 5) resulted in progressively lower coefficients of friction, which conforms to solid lubrication theory. End-of-travel wear debris and some limited coating delamination were observed within thinner areas of the coating. Therefore an amorphous carbon-graphite coating applied to 440C steel at ambient temperature exhibits solid lubricating film characteristics with high load-carrying capability. (orig.).

  7. Biodegradable, elastomeric coatings with controlled anti-proliferative agent release for magnesium-based cardiovascular stents.

    Science.gov (United States)

    Gu, Xinzhu; Mao, Zhongwei; Ye, Sang-Ho; Koo, Youngmi; Yun, Yeoheung; Tiasha, Tarannum R; Shanov, Vesselin; Wagner, William R

    2016-08-01

    Vascular stent design continues to evolve to further improve the efficacy and minimize the risks associated with these devices. Drug-eluting coatings have been widely adopted and, more recently, biodegradable stents have been the focus of extensive evaluation. In this report, biodegradable elastomeric polyurethanes were synthesized and applied as drug-eluting coatings for a relatively new class of degradable vascular stents based on Mg. The dynamic degradation behavior, hemocompatibility and drug release were investigated for poly(carbonate urethane) urea (PCUU) and poly(ester urethane) urea (PEUU) coated magnesium alloy (AZ31) stents. Poly(lactic-co-glycolic acid) (PLGA) coated and bare stents were employed as control groups. The PCUU coating effectively slowed the Mg alloy corrosion in dynamic degradation testing compared to PEUU-coated, PLGA-coated and bare Mg alloy stents. This was confirmed by electron microscopy, energy-dispersive x-ray spectroscopy and magnesium ion release experiments. PCUU-coating of AZ31 was also associated with significantly reduced platelet adhesion in acute blood contact testing. Rat vascular smooth muscle cell (rSMC) proliferation was successfully inhibited when paclitaxel was released from pre-loaded PCUU coatings. The corrosion retardation, low thrombogenicity, drug loading capacity, and high elasticity make PCUU an attractive option for drug eluting coating on biodegradable metallic cardiovascular stents. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Reflective coatings for interior and exterior of buildings and improving thermal performance

    International Nuclear Information System (INIS)

    Joudi, Ali; Svedung, Harald; Cehlin, Mathias; Rönnelid, Mats

    2013-01-01

    Highlights: ► Increase building energy efficiency by optimizing surface optical properties. ► Study different scenarios with both interior and exterior reflective coatings. ► Combined thermal effect of both interior and exterior reflective coatings. -- Abstract: The importance of reducing building energy usage and thriving for more energy efficient architectures, has nurtured creative solutions and smart choices of materials in the last few decades. Among those are optimizing surface optical properties for both interior and exterior claddings of the building. Development in the coil-coating steel industries has now made it possible to allocate correct optical properties for steel clad buildings with improved thermal performance. Although the importance of the exterior coating and solar gain are thoroughly studied in many literatures, the effect of interior cladding are less tackled, especially when considering a combination of both interior and exterior reflective coatings. This paper contemplates the thermal behavior of small cabins with reflective coatings on both interior and exterior cladding, under different conditions and climates with the aim to clarify and point out to the potential energy saving by smart choices of clad coatings.

  9. Effects of Conformal Nanoscale Coatings on Thermal Performance of Vertically Aligned Carbon Nanotubes.

    Science.gov (United States)

    Silvestri, Cinzia; Riccio, Michele; Poelma, René H; Jovic, Aleksandar; Morana, Bruno; Vollebregt, Sten; Irace, Andrea; Zhang, Guo Qi; Sarro, Pasqualina M

    2018-04-17

    The high aspect ratio and the porous nature of spatially oriented forest-like carbon nanotube (CNT) structures represent a unique opportunity to engineer a novel class of nanoscale assemblies. By combining CNTs and conformal coatings, a 3D lightweight scaffold with tailored behavior can be achieved. The effect of nanoscale coatings, aluminum oxide (Al 2 O 3 ) and nonstoichiometric amorphous silicon carbide (a-SiC), on the thermal transport efficiency of high aspect ratio vertically aligned CNTs, is reported herein. The thermal performance of the CNT-based nanostructure strongly depends on the achieved porosity, the coating material and its infiltration within the nanotube network. An unprecedented enhancement in terms of effective thermal conductivity in a-SiC coated CNTs has been obtained: 181% compared to the as-grown CNTs and Al 2 O 3 coated CNTs. Furthermore, the integration of coated high aspect ratio CNTs in an epoxy molding compound demonstrates that, next to the required thermal conductivity, the mechanical compliance for thermal interface applications can also be achieved through coating infiltration into foam-like CNT forests. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Mechanical Performance of Cold-Sprayed A357 Aluminum Alloy Coatings for Repair and Additive Manufacturing

    Science.gov (United States)

    Petráčková, K.; Kondás, J.; Guagliano, M.

    2017-12-01

    Cold-sprayed coatings made of A357 aluminum alloy, a casting alloy widely used in aerospace, underwent set of standard tests as well as newly developed fatigue test to gain an information about potential of cold spray for repair and additive manufacturing of loaded parts. With optimal spray parameters, coating deposition on substrate with smooth surface resulted in relatively good bonding, which can be further improved by application of grit blasting on substrate's surface. However, no enhancement of adhesion was obtained for shot-peened surface. Process temperature, which was set either to 450 or 550 °C, was shown to have an effect on adhesion and cohesion strength, but it does not influence residual stress in the coating. To assess cold spray perspectives for additive manufacturing, flat tensile specimens were machined from coating and tested in as-sprayed and heat-treated (solution treatment and aging) condition. Tensile properties of the coating after the treatment correspond to properties of the cast A357-T61 aluminum alloy. Finally, fatigue specimen was proposed to test overall performance of the coating and coating's fatigue limit is compared to the results obtained on cast A357-T61 aluminum alloy.

  11. Preparation and performance evaluation of epoxy-based heat reflective coating for the pavement

    Science.gov (United States)

    Hu, B.; Liang, Y. H.; Guo, L. Y.; Jiang, T.

    2017-04-01

    According to the basic characteristics and composition of heat-reflective coating, combining with the functional requirements of road materials, the experiment selects the epoxy resin with good wear resistance and adhesive force as a film forming material, with TiO2, SiO2 and extinction powder as the main functional filler. The experiment gets a good formula with suitable viscosity, low glossiness and good cooling effect, optimizes by orthogonal experiment. The experiment evaluates the indoor and outdoor cooling effect of heat-reflective coating, and analyses the road performance of the coating. The results shows that the better heat-reflective coating formula included 12% of titanium dioxide, 4% of silica and 4% of extinction powder. When the dosage of coating is 0.8kg/m2, the indoor specimen of heat-reflective coating decrease the temperature of 12 ˜ 14°C, and the specimen under solar radiation can reduce the temperature of 7 ˜ 9°C. The pavement of heat-reflective coating has good wear resistance, but the road slip resistance partly declines. Therefore, it needs to add the anti-sliding particles to meet the safe driving requirements.

  12. A new process control strategy for aqueous film coating of pellets in fluidised bed

    DEFF Research Database (Denmark)

    Larsen, C.C.; Sonnergaard, Jørn; Bertelsen, Pernille Scholdan

    2003-01-01

    The parameters with effect on maximum spray rate and maximum relative outlet air humidity when coating pellets in a fluidised bed were investigated. The tested variables include type of water based modified release film coating (Eudragit® NE 30D, Eudragit® RS 30D, Aquacoat ECD®) coating principle...... (top spray, bottom spray), inlet air humidity and type of pellets (sugar spheres, microcrystalline cellulose pellets). The maximum spray rate was not influenced by the coating principles. The highest spray rate was obtained for the film polymer with the lowest tackiness which is assumed...... to be the controlling factor. The type of pellets affected the maximum spray rate. A thermodynamic model for the coating process is employed throughout the process and not just during steady state. The thermodynamic model is incorporated into a new process control strategy. The process control strategy is based on in...

  13. Interaction of phosphorylcholine with fibronectin coatings: Surface characterization and biological performances

    Energy Technology Data Exchange (ETDEWEB)

    Montaño-Machado, Vanessa, E-mail: vanessa.montano-machado.1@ulaval.ca [Laboratory for Biomaterials and Bioengineering, Dept. of Min-Met-Materials Eng., & University Hospital Research Center, Laval University, University Campus, PLT-1745G, Québec, Québec, G1 V 0A6 (Canada); ERRMECe, University of Cergy-Pontoise, Site Saint-Martin, 2 Avenue Adolphe Chauvin, 95302 Cergy-Pontoise Cedex (France); Noël, Céline, E-mail: celine.noel@unamur.be [Research Centre in Physics of Matter and Radiation (PMR), Université de Namur, 61 rue de Bruxelles, B-5000 Namur (Belgium); Chevallier, Pascale, E-mail: pascale.chevallier@crchudequebec.ulaval.ca [Laboratory for Biomaterials and Bioengineering, Dept. of Min-Met-Materials Eng., & University Hospital Research Center, Laval University, University Campus, PLT-1745G, Québec, Québec, G1 V 0A6 (Canada); Turgeon, Stéphane, E-mail: stephane.turgeon@crchudequebec.ulaval.ca [Laboratory for Biomaterials and Bioengineering, Dept. of Min-Met-Materials Eng., & University Hospital Research Center, Laval University, University Campus, PLT-1745G, Québec, Québec, G1 V 0A6 (Canada); Houssiau, Laurent, E-mail: laurent.houssiau@unamur.be [Research Centre in Physics of Matter and Radiation (PMR), Université de Namur, 61 rue de Bruxelles, B-5000 Namur (Belgium); Pauthe, Emmanuel, E-mail: emmanuel.pauthe@u-cergy.fr [ERRMECe, University of Cergy-Pontoise, Site Saint-Martin, 2 Avenue Adolphe Chauvin, 95302 Cergy-Pontoise Cedex (France); and others

    2017-02-28

    Highlights: • Fibronectin/phosphorylcholine coatings on plasma deposited fluorocarbon films were created. • The effect of several coating techniques on the surface biological performances was evaluated. • XPS, DWCA, immunostaining and ToF-SIMS (imaging and depth profiling) techniques were applied. • Potential for cardiovascular applications was showed by endothelial cell and blood interactions. - Abstract: Coating medical devices with several bioactive molecules is an interesting approach to achieve specific biological targets upon the interaction of the biomaterial with the living environment. In this work, a fluorocarbon polymer (CF{sub x}) was first deposited by plasma treatment on stainless steel (SS) substrate and thereafter, coatings containing fibronectin (FN) and phosphorylcholine (PRC) were created for cardiovascular applications. These two biomolecules were chosen to promote endothelialization and to avoid thrombus formation, respectively. Adsorption and grafting techniques were applied – and combined – to accomplish 4 different coatings containing both molecules. However, big challenge was found to characterize a small molecule (PRC: 184 g/mol) interacting with a protein (FN: 450 kD). For the first time XPS, dynamic water contact angle, immunostaining and ToF-SIMS (imaging and depth profiling) analyses were combined to accomplish the characterization of such a coating. The most encouraging biological performances were obtained for samples where FN was grafted to the CF{sub x} film followed by the adsorption of PRC: proliferation of endothelial cells and hemocompatibility properties were observed. Promising coatings for cardiovascular applications were developed. The relevance of characterizing the coatings with high sensitive techniques and the further correlation with their biological performances were evidenced.

  14. Manufacturing issues which affect coating erosion performance in wind turbine blades

    Science.gov (United States)

    Cortés, E.; Sánchez, F.; Domenech, L.; Olivares, A.; Young, T. M.; O'Carroll, A.; Chinesta, F.

    2017-10-01

    Erosion damage, caused by repeated rain droplet impact on the leading edges of wind turbine blades, is a major cause for cost concern. Resin Infusion (RI) is used in wind energy blades where low weight and high mechanical performance materials are demanded. The surface coating plays a crucial role in the manufacturing and performance response. The Leading Edge coating is usually moulded, painted or sprayed onto the blade surface so adequate adhesion in the layers' characterization through the thickness is required for mechanical performance and durability reasons. In the current work, an investigation has been directed into the resulting rain erosion durability of the coating was undertaken through a combination of mass loss testing measurements with manufacturing processing parameter variations. The adhesion and erosion is affected by the shock wave caused by the collapsing water droplet on impact. The stress waves are transmitted to the substrate, so microestructural discontinuities in coating layers and interfaces play a key role on its degradation. Standard industrial systems are based on a multilayer system, with a high number of interfaces that tend to accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations and their potential stress reduction on the interface. In this research, the input parameters for the appropriate definition of the Cohesive Zone Modelling (CZM) of the coating-substrate interface are outlined by means of Pull off testing and Peeling testing results. It allowed one to optimize manufacturing and coating process for blades into a knowledge-based guidance for leading edge coating material development. It was achieved by investigating the erosion degradation process using both numerical and laboratory techniques (Pull off, Peeling and Rain Erosion Testing in a whirling arm rain erosion test facility).

  15. Control over Coating Structure during Electromagnetic Welding and Application of HighSpeed Steel Powder

    Directory of Open Access Journals (Sweden)

    L. M. Kozhuro

    2004-01-01

    Full Text Available The paper considers peculiar features concerning coating formation in the process of electromagnetic welding of high-speed steel powder. The paper reveals how to control coating structure that ensures the required operational properties of working surfaces of machine parts. 

  16. Vesicle coating and uncoating: controlling the formation of large COPII-coated carriers.

    Science.gov (United States)

    Townley, Anna K; Stephens, David J

    2009-08-26

    The basic mechanisms underlying the formation of coated vesicles are now defined in considerable detail. This article highlights recent developments in our understanding of the problem of exporting large macromolecular cargo such as procollagen from the endoplasmic reticulum and discusses the implications that this has for cell and tissue organisation and human disease.

  17. Sequestration Coating Performance Requirements for Mitigation of Contamination from a Radiological Dispersion Device

    International Nuclear Information System (INIS)

    Drake, J.

    2009-01-01

    Immediate action would be necessary to minimize the effects of a radiological 'dirty bomb' detonation in a major city. After a dirty bomb has been detonated, vehicular and pedestrian traffic, as well as weather effects, would increase the spread of loose contamination, making control and recovery more difficult and costly. While contaminant migration and chemical binding into surface materials can be relatively rapid, the immediate treatment of surfaces with large quantities of an appropriate compound could alleviate much of the difficulty in decontamination. The EPA's National Homeland Security Research Center (NHSRC), in collaboration with ASTM International, is currently developing performance standards for materials which could be applied to exterior surfaces contaminated by an RDD to mitigate the spread and migration of radioactive contamination. These performance standards are being promulgated via an ASTM Standard Specification to be published by ASTM International. Test methods will be developed to determine if candidate coatings meet the performance requirements stipulated in the ASTM performance standard. These test methods will be adapted from existing standard methods, or will be devised through laboratory research. The final set of test methods will be codified in an ASTM or other standard test method. The principal market for products described in the ASTM performance standard would be federal, state and local government emergency responders and response planners, decontamination service providers and those whose interests include protection and recovery of real estate potentially at risk from radiological terrorism. (authors)

  18. Effect of solder flux residue on the performance of silicone conformal coatings on printed circuit board assemblies

    DEFF Research Database (Denmark)

    Rathinavelu, Umadevi; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    Conformal coatings are applied on printed circuit board assemblies (PCBAs) in order to protect the assembly from environmental influence and silicone-based coating is commonly used. A systematic study on the performance of silicone conformal coating in connection with process-related contaminants...

  19. Performance and durability tests of smart icephobic coatings to reduce ice adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Janjua, Zaid A.; Turnbull, Barbara [Faculty of Engineering, University of Nottingham (United Kingdom); Choy, Kwang-Leong; Pandis, Christos [Institute for Materials Discovery, University College London (UCL) (United Kingdom); Liu, Junpeng; Hou, Xianghui; Choi, Kwing-So [Faculty of Engineering, University of Nottingham (United Kingdom)

    2017-06-15

    Highlights: • Repeated ice adhesion and removal occurs on nanocoatings. • Icephobicity of nanocoatings reduces with each test cycle. • Adhesion strength linked to contact angle hysteresis in Gaussian fit. • Icephobicity not linked to hydrophobicity. - Abstract: The accretion of ice can cause damage in applications ranging from power lines and shipping decks, to wind turbines and rail infrastructure. In particular on aircraft, it can change aerodynamic characteristics, greatly affecting the flight safety. Commercial aircraft are therefore required to be equipped with de-icing devices, such as heating mats over the wings. The application of icephobic coatings near the leading edge of a wing can in theory reduce the high power requirements of heating mats, which melt ice that forms there. Such coatings are effective in preventing the accretion of runback ice, formed from airborne supercooled droplets, or the water that the heating mats generate as it is sheared back over the wing's upper surface. However, the durability and the practicality of applying them over a large wing surface have been prohibitive factors in deploying this technology so far. Here, we evaluated the ice adhesion strength of four non-conductive coatings and seven thermally conductive coatings by shearing ice samples from coated plates by spinning them in a centrifuge device. The durability of the coating performance was also assessed by repeating the tests, each time regrowing ice samples on the previously-used coatings. Contact angle parameters of each coating were tested for each test to determine influence on ice adhesion strength. The results indicate that contact angle hysteresis is a crucial parameter in determining icephobicity of a coating and hydrophobicity is not necessarily linked to icephobicity.

  20. Tribological performance of an H-DLC coating prepared by PECVD

    Science.gov (United States)

    Solis, J.; Zhao, H.; Wang, C.; Verduzco, J. A.; Bueno, A. S.; Neville, A.

    2016-10-01

    Carbon-based coatings are of wide interest due to their application in machine elements subjected to continuous contact where fluid lubricant films are not permitted. This paper describes the tribological performance under dry conditions of duplex layered H-DLC coating sequentially deposited by microwave excited plasma enhanced chemical vapour deposition on AISI 52100 steel. The architecture of the coating comprised Cr, WC, and DLC (a-C:H) with a total thickness of 2.8 μm and compressive residual stress very close to 1 GPa. Surface hardness was approximately 22 GPa and its reduced elastic modulus around 180 GPa. Scratch tests indicated a well adhered coating achieving a critical load of 80 N. The effect of normal load on the friction and wear behaviours were investigated with steel pins sliding against the actual coating under dry conditions at room temperature (20 ± 2 °C) and 35-50% RH. The results show that coefficient of friction of the coating decreased from 0.21 to 0.13 values with the increase in the applied loads (10-50 N). Specific wear rates of the surface coating also decrease with the increase in the same range of applied loads. Maximum and minimum values were 14 × 10-8 and 5.5 × 10-8 mm-3/N m, respectively. Through Raman spectroscopy and electron microscopy it was confirmed the carbon-carbon contact, due to the tribolayer formation on the wear scars of the coating and pin. In order to further corroborate the experimental observations regarding the graphitisation behaviour, the existing mathematical relationships to determine the graphitisation temperature of the coating/steel contact as well as the flash temperature were used.

  1. The calcium phosphate coating of soy lecithin nanoemulsion with performance in stability and as an oxygen carrier

    Science.gov (United States)

    Han, Kyu B.

    This work studied the relationship between surfactant, oil, and water, by building ternary phase diagrams, the goal of which was to identify the oil-in-water phase composition. The resulting nano-sized emulsion was coated with dicalcium phosphate by utilizing the ionic affinity between calcium ions and the emulsion surface. Since the desired function of the particle is as an oxygen carrier, the particle stability, oxygen capacity, and oxygen release rate were investigated. The first step in the process was to construct ternary phase diagrams with 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA) and soy derived lecithin. The results showed that the lecithin surfactant formed an oil-in-water phase region that was 36 times greater than that of DOPA. With the desired phase composition set, the lecithin emulsion was extruded, resulting in a well-dispersed nanosized particle. A pH titration study of the emulsion found an optimized calcium phosphate coating condition at pH 8.8, at which, the calcium ion had a greater affinity for the emulsion surface than phosphate. A Hill plot was used to show calcium cooperativeness on the emulsion surface which suggested one calcium ion binds to one lecithin molecule. The lecithin emulsion particles were then coated with calcium phosphate using a layering technique that allowed for careful control of the coating thickness. The overall particle hydrodynamic radius was consistent with the growth of the calcium phosphate coating, from 8 nm to 28 nm. This observation was further supported with cryo-TEM measurements. The stability of the coated emulsion was tested in conditions that simulate practical thermal, physical, and time-dependent conditions. Throughout the tests, the coated emulsion exhibited a constant mono-dispersed particle size, while the uncoated emulsion size fluctuated greatly and exhibited increased polydispersion. The fast mixing method with the stopped-flow apparatus was employed to test the product as an oxygen carrier, and it

  2. Protective Performance of Polyaniline-Sulfosalicylic Acid/Epoxy Coating for 5083 Aluminum

    Science.gov (United States)

    Liu, Suyun; Liu, Li; Meng, Fandi; Li, Ying; Wang, Fuhui

    2018-01-01

    Epoxy coatings incorporating different content of sulfosalicylic acid doped polyaniline (PANI-SSA) have been investigated for corrosion protection of 5083 aluminum alloy in 3.5% NaCl solution. The performance of the coatings is studied using a combination of electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), gravimetric tests, adhesion tests, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that the content of PANI-SSA not only affects the coating compactness and the transportation of aggressive medium, but also has a significant influence on the-based aluminum. The coating with 2 wt. % PANI-SSA exhibits the best corrosion inhibition due to its good protective properties and the formation of a complete PANI-SSA induced oxide layer. PMID:29438304

  3. Anticorrosive Performance of Zinc Phosphate Coatings on Mild Steel Developed Using Galvanic Coupling

    Directory of Open Access Journals (Sweden)

    M. Arthanareeswari

    2013-01-01

    Full Text Available The anticorrosive performance of zinc phosphate coatings developed by galvanic coupling technique on mild steel substrates using the cathode materials such as titanium (Ti, copper (Cu, brass (BR, nickel (Ni, and stainless steel (SS is elucidated in this study. Thermal and chemical stability tests, immersion test in 3.5% NaCl, ARE salt droplet test, and salt spray test were carried out. The study reveals that the mild steel substrates phosphated under galvanically coupled condition showed better corrosion resistance than the one coated without coupling. The open circuit potential (OCP of phosphated mild steel panels in 3.5% NaCl was found to be a function of phosphate coating weight and porosity of the coating.

  4. Analyses of performance of novel sensors with different coatings for detection of Lipopolysaccharide

    KAUST Repository

    Mohd. Syaifudin, A. R.

    2011-10-01

    Interdigital sensors have been widely used for non-destructive applications. New types of planar interdigital sensors have been fabricated with different coating materials to assess the response to Lipopolysaccharide, LPS. All the coatings were selected and optimized to be stable in water, as the measurements take place in water media. Moreover, the coatings have been designed to have available carboxylic or amine functional groups. The use of these functional groups is a widely used technique to specifically binding of biomolecules. The coated sensors were then immobilized with Polymyxin B(PmB) which has the specific binding properties to LPS. This paper will highlight the fabrication process and initial investigations on the sensors\\' performance based on Impedance Spectroscopy. © 2011 IEEE.

  5. ACCESS: Detector Control and Performance

    Science.gov (United States)

    Morris, Matthew J.; Kaiser, M.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Bohlin, R.; Kurucz, R. L.; Riess, A. G.; Pelton, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Mott, D. B.; Wen, Y.; Benford, D. J.; Gardner, J. P.; Feldman, P. D.; Moos, H. W.; Lampton, M.; Perlmutter, S.; Woodgate, B. E.

    2014-01-01

    ACCESS, Absolute Color Calibration Experiment for Standard Stars, is a series of rocket-borne sub-orbital missions and ground-based experiments that will enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass (companion poster, Kaiser et al.). The flight detector and detector spare have been selected and integrated with their electronics and flight mount. The controller electronics have been flight qualified. Vibration testing to launch loads and thermal vacuum testing of the detector, mount, and housing have been successfully performed. Further improvements to the flight controller housing have been made. A cryogenic ground test system has been built. Dark current and read noise tests have been performed, yielding results consistent with the initial characterization tests of the detector performed by Goddard Space Flight Center’s Detector Characterization Lab (DCL). Detector control software has been developed and implemented for ground testing. Performance and integration of the detector and controller with the flight software will be presented. NASA APRA sounding rocket grant NNX08AI65G supports this work.

  6. Characterization and antibacterial performance of bioactive Ti–Zn–O coatings deposited on titanium implants

    International Nuclear Information System (INIS)

    Tsai, Ming-Tzu; Chang, Yin-Yu; Huang, Heng-Li; Hsu, Jui-Ting; Chen, Ya-Chi; Wu, Aaron Yu-Jen

    2013-01-01

    Titanium (Ti)-based materials have been used for dental and orthopedic implants because of their excellent biological compatibility, superior mechanical strength, and high corrosion resistance. The hypothesis of this present study was to manufacture the Zn-doped TiO 2 layer possessing the biocompatibility and antibacterial ability on the surface of Ti specimens. TiO 2 , ZnO, and Ti(Zn)O 2 coatings were deposited on polished pure Ti substrates using a cathodic arc deposition system. Murine osteoblasts (MC3T3-E1) and human Staphylococcus aureus (S. aureus) were cultured onto the surface with different deposited coatings, respectively. The biocompatibility was examined by cell viability and osteogenic gene expression. The antibacterial ability was determined by SYTO9 nucleic acid staining. A porous Zn-doped TiO 2 coating was successfully produced. The ZnO exhibited a fibrous structure with nanorods showing a hydrophobic feature (contact angle approximately 89°). These material properties affected the following biological performance. The antibacterial testing found no apparent difference between the uncoated Ti plate and the TiO 2 coating. However, significantly lower numbers of S. aureus were observed on ZnO and Ti(Zn)O 2 coatings compared to that on the uncoated Ti. The biocompatible testing exhibited that TiO 2 and Ti(Zn)O 2 coatings enhanced greater cell viability and proliferation than the uncoated Ti plate and ZnO coating. The osteogenic gene expression of Dlx-5 and osterix also improved for the TiO 2 and Ti(Zn)O 2 coatings. However, a significant inhibition of cell viability was found for the ZnO coating. These findings suggested that the composite Ti(Zn)O 2 coating with a lower content of Zn (7.6 ± 1.3 at.%) not only improved antibacterial activity, but also maintained the biocompatibility to bone cells. - Highlights: ► TiO 2 , Ti(Zn)O 2 and ZnO coatings were deposited by cathodic arc evaporation. ► Zn may incorporated with Ti to form Zn-doped TiO 2 .

  7. Characterization and antibacterial performance of bioactive Ti–Zn–O coatings deposited on titanium implants

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ming-Tzu [Department of Biomedical Engineering, Hungkuang University, Taichung 433, Taiwan (China); Chang, Yin-Yu, E-mail: yinyu@nfu.edu.tw [Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin 632, Taiwan (China); Huang, Heng-Li; Hsu, Jui-Ting [School of Dentistry, College of Medicine China Medical University, Taichung 404, Taiwan (China); Chen, Ya-Chi [Department of Materials Science and Engineering, Mingdao University, Changhua 523, Taiwan (China); Wu, Aaron Yu-Jen [Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833, Taiwan (China)

    2013-01-01

    Titanium (Ti)-based materials have been used for dental and orthopedic implants because of their excellent biological compatibility, superior mechanical strength, and high corrosion resistance. The hypothesis of this present study was to manufacture the Zn-doped TiO{sub 2} layer possessing the biocompatibility and antibacterial ability on the surface of Ti specimens. TiO{sub 2}, ZnO, and Ti(Zn)O{sub 2} coatings were deposited on polished pure Ti substrates using a cathodic arc deposition system. Murine osteoblasts (MC3T3-E1) and human Staphylococcus aureus (S. aureus) were cultured onto the surface with different deposited coatings, respectively. The biocompatibility was examined by cell viability and osteogenic gene expression. The antibacterial ability was determined by SYTO9 nucleic acid staining. A porous Zn-doped TiO{sub 2} coating was successfully produced. The ZnO exhibited a fibrous structure with nanorods showing a hydrophobic feature (contact angle approximately 89°). These material properties affected the following biological performance. The antibacterial testing found no apparent difference between the uncoated Ti plate and the TiO{sub 2} coating. However, significantly lower numbers of S. aureus were observed on ZnO and Ti(Zn)O{sub 2} coatings compared to that on the uncoated Ti. The biocompatible testing exhibited that TiO{sub 2} and Ti(Zn)O{sub 2} coatings enhanced greater cell viability and proliferation than the uncoated Ti plate and ZnO coating. The osteogenic gene expression of Dlx-5 and osterix also improved for the TiO{sub 2} and Ti(Zn)O{sub 2} coatings. However, a significant inhibition of cell viability was found for the ZnO coating. These findings suggested that the composite Ti(Zn)O{sub 2} coating with a lower content of Zn (7.6 ± 1.3 at.%) not only improved antibacterial activity, but also maintained the biocompatibility to bone cells. - Highlights: ► TiO{sub 2}, Ti(Zn)O{sub 2} and ZnO coatings were deposited by cathodic arc

  8. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial

  9. Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture.

    Science.gov (United States)

    Karthikeya Sharma, T

    2015-11-01

    Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine's performance within the range studied.

  10. Laboratory and gas-fired furnace performance tests of epoxy primers for intumescent coatings

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Catala, Pere

    2014-01-01

    , either to ensure adhesion of the intumescent coating to the steel or to provide corrosion resistance. It is essential to document the performance of the intumescent coating together with the primer to ensure the overall quality of coating system. In the present work, two epoxy primers were used...... to a gas-fired furnace following the ISO834 fire curve (a so-called cellulosic fire), one of the primers selected performed well and the other poorly. From tests in the electrically heated oven, it was found that both primers were sensitive to the film thickness employed and the presence of oxygen....... At oxygen-rich conditions, higher primer thicknesses gave weaker performance. In addition, a color change from red to black was observed in nitrogen, while the color remained red in the oxygen-nitrogen mixture. In summary, the results suggest that an adequate choice of primer, primer thickness...

  11. Adsorption of alginate and albumin on aluminum coatings inhibits adhesion of Escherichia coli and enhances the anti-corrosion performances of the coatings

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiaoyan; Liu, Yi; Huang, Jing; Chen, Xiuyong; Ren, Kun; Li, Hua, E-mail: lihua@nimte.ac.cn

    2015-03-30

    Graphical abstract: - Highlights: • Adsorption behaviors of alginate and albumin on Al coatings were investigated at molecular level. • The adsorption inhibits effectively the colonization of Escherichia coli bacteria. • The adsorption alters the wettability of the Al coatings. • The conditioning layer enhances anti-corrosion performances of the Al coatings. - Abstract: Thermal-sprayed aluminum coatings have been extensively used as protective layers against corrosion for steel structures in the marine environment. The corrosion usually deteriorates from marine biofouling, yet the mechanism of accelerated corrosion of the coatings remains elusive. As the first stage participating in biofouling process, adsorption of molecules plays critical roles in mediating formation of biofilm. Here, we report at molecular level the adsorption behaviors of albumin and marine polysaccharide on arc-sprayed aluminum coatings and their influence on adhesion of Escherichia coli. The adsorption of alginate and albumin was characterized by infrared spectra analyses and atomic force microscopic observation. The adsorption inhibits effectively adhesion of the bacteria. Further investigation indicates that alginate/albumin altered the hydrophilicity/hydrophobicity of the coatings instead of impacting the survival of the bacteria to decline their adhesion. The conditioning layer composed of the molecules enhances anti-corrosion performances of the coatings.

  12. Adsorption of alginate and albumin on aluminum coatings inhibits adhesion of Escherichia coli and enhances the anti-corrosion performances of the coatings

    International Nuclear Information System (INIS)

    He, Xiaoyan; Liu, Yi; Huang, Jing; Chen, Xiuyong; Ren, Kun; Li, Hua

    2015-01-01

    Graphical abstract: - Highlights: • Adsorption behaviors of alginate and albumin on Al coatings were investigated at molecular level. • The adsorption inhibits effectively the colonization of Escherichia coli bacteria. • The adsorption alters the wettability of the Al coatings. • The conditioning layer enhances anti-corrosion performances of the Al coatings. - Abstract: Thermal-sprayed aluminum coatings have been extensively used as protective layers against corrosion for steel structures in the marine environment. The corrosion usually deteriorates from marine biofouling, yet the mechanism of accelerated corrosion of the coatings remains elusive. As the first stage participating in biofouling process, adsorption of molecules plays critical roles in mediating formation of biofilm. Here, we report at molecular level the adsorption behaviors of albumin and marine polysaccharide on arc-sprayed aluminum coatings and their influence on adhesion of Escherichia coli. The adsorption of alginate and albumin was characterized by infrared spectra analyses and atomic force microscopic observation. The adsorption inhibits effectively adhesion of the bacteria. Further investigation indicates that alginate/albumin altered the hydrophilicity/hydrophobicity of the coatings instead of impacting the survival of the bacteria to decline their adhesion. The conditioning layer composed of the molecules enhances anti-corrosion performances of the coatings

  13. Corrosion protection performance of waterborne epoxy coatings containing self-doped polyaniline nanofiber

    International Nuclear Information System (INIS)

    Qiu, Shihui; Chen, Cheng; Cui, Mingjun; Li, Wei; Zhao, Haichao; Wang, Liping

    2017-01-01

    Highlights: • Self-dopedpolyaniline (SPANi) with good conductivity and dispersibility in water was copolymerized by aniline and its derivative. • Environmental friendly SPANi/epoxy composite coating with remarkable anti-corrosion performance was prepared. • The corrosion product of pure epoxy or composite coating was characterized by X-ray diffraction pattern and scanning electron microscope (SEM). - Abstract: Self-doped sulfonated polyaniline (SPANi) nanofiber was synthesized by the copolymerization of 2-aminobenzenesulfonic acid (ASA) and aniline via a rapid mixing polymerization approach. The chemical structure of SPANi was investigated by the Fourier-transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), UV–vis spectra and X-ray diffraction (XRD) pattern. The as-prepared SPANi nanofibers had 45 nm average diameter and length up to 750 nm as measured by scanning electron microscope (SEM) and transmission electron microscope (TEM). The self-doped SPANi nanofiber possessed excellent aqueous solubility, good conductivity (0.11 S/cm) and reversible redox activity, making it suitable as a corrosion inhibitor for waterborne coatings. The prepared SPANi/waterborne epoxy composite coatings exhibited remarkably improved corrosion protection compared with pure waterborne epoxy coating as proved by the polarization curves and electrochemical impedance spectroscopy (EIS). The passivation effect of SPANi nanofiber and the corrosion products beneath the epoxy coatings immersed in 3.5% NaCl solution as a function of time were also investigated in this study.

  14. Corrosion protection performance of waterborne epoxy coatings containing self-doped polyaniline nanofiber

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Shihui [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 (China); Chen, Cheng; Cui, Mingjun [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Li, Wei [Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 (China); Zhao, Haichao, E-mail: zhaohaichao@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Wang, Liping, E-mail: wangliping@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China)

    2017-06-15

    Highlights: • Self-dopedpolyaniline (SPANi) with good conductivity and dispersibility in water was copolymerized by aniline and its derivative. • Environmental friendly SPANi/epoxy composite coating with remarkable anti-corrosion performance was prepared. • The corrosion product of pure epoxy or composite coating was characterized by X-ray diffraction pattern and scanning electron microscope (SEM). - Abstract: Self-doped sulfonated polyaniline (SPANi) nanofiber was synthesized by the copolymerization of 2-aminobenzenesulfonic acid (ASA) and aniline via a rapid mixing polymerization approach. The chemical structure of SPANi was investigated by the Fourier-transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), UV–vis spectra and X-ray diffraction (XRD) pattern. The as-prepared SPANi nanofibers had 45 nm average diameter and length up to 750 nm as measured by scanning electron microscope (SEM) and transmission electron microscope (TEM). The self-doped SPANi nanofiber possessed excellent aqueous solubility, good conductivity (0.11 S/cm) and reversible redox activity, making it suitable as a corrosion inhibitor for waterborne coatings. The prepared SPANi/waterborne epoxy composite coatings exhibited remarkably improved corrosion protection compared with pure waterborne epoxy coating as proved by the polarization curves and electrochemical impedance spectroscopy (EIS). The passivation effect of SPANi nanofiber and the corrosion products beneath the epoxy coatings immersed in 3.5% NaCl solution as a function of time were also investigated in this study.

  15. Controlling the scattering properties of thin, particle-doped coatings

    Science.gov (United States)

    Rogers, William; Corbett, Madeleine; Manoharan, Vinothan

    2013-03-01

    Coatings and thin films of small particles suspended in a matrix possess optical properties that are important in several industries from cosmetics and paints to polymer composites. Many of the most interesting applications require coatings that produce several bulk effects simultaneously, but it is often difficult to rationally formulate materials with these desired optical properties. Here, we focus on the specific challenge of designing a thin colloidal film that maximizes both diffuse and total hemispherical transmission. We demonstrate that these bulk optical properties follow a simple scaling with two microscopic length scales: the scattering and transport mean free paths. Using these length scales and Mie scattering calculations, we generate basic design rules that relate scattering at the single particle level to the film's bulk optical properties. These ideas will be useful in the rational design of future optically active coatings.

  16. CHARACTERIZATION AND PERFORMANCE OF DUPLEX-COATINGS ON Cr-V COLD WORK TOOL STEEL

    Directory of Open Access Journals (Sweden)

    Peter Jurči

    2015-09-01

    Full Text Available Specimens made of Vanadis 6 steel were heat treated, plasma nitrided and coated with Cr2N. The microstructure, phase constitution and mechanical properties of plasma nitrided areas and duplex-coatings have been investigated using the light microscopy, scanning electron microscopy, X-ray diffraction and microhardness measurements. The adhesion of the coatings and the wear performance were studied using the scratch test and ring-on-plate tribological testing. Worn surfaces were examined by scanning electron microscopy. Nitrided areas formed at lower temperature were free of compound “white” layer while hose developed at higher temperatures contained as the white layer so the nitrided network. Significant increase in substrate hardness was detected due to the nitriding. Beneficial effect of the nitriding on the adhesion of Cr2N coatings was clearly determined whereas the extent in improvement of the adhesion depends on the presence/no presence of “white” layer on the surface. The extent of beneficial effect of plasma nitriding on the wear performance follows the impact of the constitution of nitrided areas on the adhesion. The amelioration of wear performance of Cr2N coatings can be attributed to the supporting effect of hard nitrided intermediate region, which provides excellent resistance of the substrate against plastic deformation, under heavy loading in particular. Practical testing demonstrated many times prolonged service-time of duplex-treated tools for sheet metal working.

  17. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2015-07-15

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  18. High temperature glass thermal control structure and coating. [for application to spacecraft reusable heat shielding

    Science.gov (United States)

    Stewart, D. A.; Goldstein, H. E.; Leiser, D. B. (Inventor)

    1983-01-01

    A high temperature stable and solar radiation stable thermal control coating is described which is useful either as such, applied directly to a member to be protected, or applied as a coating on a re-usable surface insulation (RSI). It has a base coat layer and an overlay glass layer. The base coat layer has a high emittance, and the overlay layer is formed from discrete, but sintered together glass particles to give the overlay layer a high scattering coefficient. The resulting two-layer space and thermal control coating has an absorptivity-to-emissivity ratio of less than or equal to 0.4 at room temperature, with an emittance of 0.8 at 1200 F. It is capable of exposure to either solar radiation or temperatures as high as 2000 F without significant degradation. When used as a coating on a silica substrate to give an RSI structure, the coatings of this invention show significantly less reduction in emittance after long term convective heating and less residual strain than prior art coatings for RSI structures.

  19. On the Material Characterisation of Wind Turbine Blade Coatings: The Effect of Interphase Coating-Laminate Adhesion on Rain Erosion Performance.

    Science.gov (United States)

    Cortés, Enrique; Sánchez, Fernando; O'Carroll, Anthony; Madramany, Borja; Hardiman, Mark; Young, Trevor M

    2017-09-28

    Rain erosion damage, caused by repeated droplet impact on wind turbine blades, is a major cause for concern, even more so at offshore locations with larger blades and higher tip speeds. Due to the negative economic influence of blade erosion, all wind turbine Original Equipment Manufacturers (OEMs) are actively seeking solutions. In most cases, since the surface coating plays a decisive role in the blade manufacture and overall performance, it has been identified as an area where a solution may be obtained. In this research, two main coating technologies have been considered: In-mould coatings (Gel coating) applied during moulding on the entire blade surface and the post-mould coatings specifically developed for Leading Edge Protection (LEP). The coating adhesion and erosion is affected by the shock waves created by the collapsing water droplets on impact. The stress waves are reflected and transmitted to the laminate substrate, so microstructural discontinuities in coating layers and interfaces play a key role on its degradation and may accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations based on their potential stress reduction on the interface. Nevertheless, in order to use them, it is necessary to measure the contact adhesion resistance of the multi-layered system interfaces. The rain erosion performance is assessed using an accelerated testing technique, whereby the test material is repeatedly impacted at high speed with water droplets in a Whirling Arm Rain Erosion Rig (WARER). The materials, specifically the coating-laminate interphase region and acoustic properties, are further characterised by several laboratory tests, including Differential Scanning Calorimetry (DSC), pull-off testing, peeling-adhesion testing and nanoindentation testing. This body of work includes a number of case studies. The first case study compares two

  20. Optimizing Compliance and Thermal Conductivity of Plasma Sprayed Thermal Barrier Coatings via Controlled Powders and Processing Strategies

    Science.gov (United States)

    Tan, Yang; Srinivasan, Vasudevan; Nakamura, Toshio; Sampath, Sanjay; Bertrand, Pierre; Bertrand, Ghislaine

    2012-09-01

    The properties and performance of plasma-sprayed thermal barrier coatings (TBCs) are strongly dependent on the microstructural defects, which are affected by starting powder morphology and processing conditions. Of particular interest is the use of hollow powders which not only allow for efficient melting of zirconia ceramics but also produce lower conductivity and more compliant coatings. Typical industrial hollow spray powders have an assortment of densities resulting in masking potential advantages of the hollow morphology. In this study, we have conducted process mapping strategies using a novel uniform shell thickness hollow powder to control the defect microstructure and properties. Correlations among coating properties, microstructure, and processing reveal feasibility to produce highly compliant and low conductivity TBC through a combination of optimized feedstock and processing conditions. The results are presented through the framework of process maps establishing correlations among process, microstructure, and properties and providing opportunities for optimization of TBCs.

  1. The erosion performance of cold spray deposited metal matrix composite coatings with subsequent friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Peat, Tom, E-mail: tompeat12@gmail.com [Department of Mechanical & Aerospace Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ (United Kingdom); Galloway, Alexander; Toumpis, Athanasios [Department of Mechanical & Aerospace Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ (United Kingdom); McNutt, Philip [TWI Ltd., Granta Park, Cambridge CB21 6AL (United Kingdom); Iqbal, Naveed [TWI Technology Centre, Wallis Way, Catcliff, Rotherham, S60 5TZ (United Kingdom)

    2017-02-28

    Highlights: • WC-CoCr, Cr{sub 3}C{sub 2}-NiCr and Al{sub 2}O{sub 3} coatings were cold spray deposited on AA5083 and friction stir processed. • The SprayStirred WC-CoCr demonstrated a hardness increase of 100% over the cold sprayed coating. • As-deposited and SprayStirred coatings were examined under slurry erosion test conditions. • Mass and volume loss was measured following 20-min exposure to the slurry. • The WC-CoCr and Al2O3 demonstrated a reduction in volume loss of approx. 40% over the cold sprayed coating. - Abstract: This study forms an initial investigation into the development of SprayStir, an innovative processing technique for generating erosion resistant surface layers on a chosen substrate material. Tungsten carbide – cobalt chromium, chromium carbide – nickel chromium and aluminium oxide coatings were successfully cold spray deposited on AA5083 grade aluminium. In order to improve the deposition efficiency of the cold spray process, coatings were co-deposited with powdered AA5083 using a twin powder feed system that resulted in thick (>300 μm) composite coatings. The deposited coatings were subsequently friction stir processed to embed the particles in the substrate in order to generate a metal matrix composite (MMC) surface layer. The primary aim of this investigation was to examine the erosion performance of the SprayStirred surfaces and demonstrate the benefits of this novel process as a surface engineering technique. Volumetric analysis of the SprayStirred surfaces highlighted a drop of approx. 40% in the level of material loss when compared with the cold spray deposited coating prior to friction stir processing. Micro-hardness testing revealed that in the case of WC-CoCr reinforced coating, the hardness of the SprayStirred material exhibits an increase of approx. 540% over the unaltered substrate and 120% over the as-deposited composite coating. Microstructural examination demonstrated that the increase in the hardness of the

  2. Microwave absorption properties of carbon nanocoils coated with highly controlled magnetic materials by atomic layer deposition.

    Science.gov (United States)

    Wang, Guizhen; Gao, Zhe; Tang, Shiwei; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Lin, Shiwei; Feng, Yuhong; Zhou, Lei; Qin, Yong

    2012-12-21

    In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe(3)O(4) or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.

  3. Controlling the Biodegradation of Magnesium Implants Through Nanostructured Calcium-Phosphate Coating

    Science.gov (United States)

    Iskandar, Maria Emil

    Magnesium (Mg) alloys, a novel class of degradable, metallic biomaterials, have attracted growing interest as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. Moreover, Mg is biodegradable in the physiological environments. However, the major obstacle for Mg to be used as medical implants is its rapid degradation in physiological fluids. Therefore, the present key challenge lies in controlling Mg degradation rate in the physiological environment. The objective of this study was to develop a nanostructured-hydroxyapatite (nHA) coating on polished Mg implants to control the degradation and bone tissue integration of the implants. The nHA coatings were deposited on Mg using the Spire's patented TPA process to moderate the aggressive degradation of Mg and to improve quick osteointegration between Mg and natural bone. Nanostructured-HA coatings mimic the nanostructure and chemistry of natural bone, which will provide a desirable environment for bone tissue regeneration. Surface morphology, element compositions, and crystal structures were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and x-ray diffractometry (XRD), respectively. SEM images of the deposited nHA-coating was analyzed using ImageJ's quantitative image analysis tool, to determine the nHA-coating particle size and thickness. The degradation of nHA-coated and non-coated Mg samples was investigated by incubating samples in phosphate buffered saline (PBS) and revised simulated body fluid (r-SBF), under standard cell culture conditions. To mimic the in vivo cell response in the physiological environment, rat bone marrow stromal cells (BMSC) were harvested and cultured with nHA-coated and non-coated polished Mg samples to determine cytocompatibilty. The degradation results suggested that the nanocoatings positively mediated Mg degradation. It can therefore be concluded that nHA-coatings

  4. Development of high performance electroless Ni-P-HNT composite coatings

    Science.gov (United States)

    Ranganatha, S.; Venkatesha, T. V.; Vathsala, K.

    2012-12-01

    Halloysite nanotubes (HNTs) of the dimension 50 nm × 1-3 μm (diameter × length) are utililized to fabricate the alloy composite by employing electroless/autocatalytic deposition technique. Electroless Ni-P-HNT binary alloy composite coatings are prepared successfully on low carbon steel. These nanotubes were made to get inserted/incorporated into nickel matrix and corresponding composites are examined for their electrochemical, mechanical and tribological performances and compared with that of plain Ni-P. The coatings were characterized using scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDX) techniques to analyze surface nature and composition correspondingly. Small amount of incorporated HNTs made Ni-P deposits appreciable enhancement and betterment in corrosion resistance, hardness and friction resistance. This drastic improvement in the properties reflects the effect of addition of HNTs into Ni-P matrix leading to the development of high performance Ni-P-HNT composite coatings.

  5. Review on Electroless Plating Ni-P Coatings for Improving Surface Performance of Steel

    Science.gov (United States)

    Zhang, Hongyan; Zou, Jiaojuan; Lin, Naiming; Tang, Bin

    2014-04-01

    Electroless plating has been considered as an effective approach to provide protection and enhancement for metallic materials with many excellent properties in engineering field. This paper begins with a brief introduction of the fundamental aspects underlying the technological principles and conventional process of electroless nickel-phosphorus (Ni-P) coatings. Then this paper discusses different electroless nickel plating, including binary plating, ternary composite plating and nickel plating with nanoparticles and rare earth, with the intention of improving the surface performance on steel substrate in recent years in detail. Based on different coating process, the varied features depending on the processing parameters are highlighted. Separately, diverse preparation techniques aiming at improvement of plating efficiency are summarized. Moreover, in view of the outstanding performance, such as corrosion resistance, abrasive resistance and fatigue resistance, this paper critically reviews the behaviors and features of various electroless coatings under different conditions.

  6. Radiation curing of intelligent coating for controlled release and permeation

    International Nuclear Information System (INIS)

    Nakayama, Hiroshi; Kaetsu, Isao; Uchida, Kumao; Sakata, Shoei; Tougou, Kazuhide; Hara, Takamichi; Matsubara, Yoshio

    2002-01-01

    Intelligent membranes for pH and temperature-responsive drug releases were developed by coating and curing of polymer-drug composite film with electrolyte or N-isopropyl acrylamide curable mixture. It was proved that those intelligent membranes showed the stimule-sensitive and responsive release functions and could be produced efficiently by radiation curing processing with a conveyer system

  7. Influence of hydroxyapatite coating thickness and powder particle size on corrosion performance of MA8M magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sonmez, S. [Hakkari University, Dept. of Biomedical Eng., 30000 Hakkari (Turkey); Aksakal, B., E-mail: baksakal@yildiz.edu.tr [Yildiz Technical University, Chemical Metallurgy Faculty, Dept. of Metall and Mater Eng., Istanbul (Turkey); Dikici, B. [Yuzuncu Yil University, Dept. of Mechanical Eng., 65080 Van (Turkey)

    2014-05-01

    Graphical abstract: The corrosion resistance of magnesium alloys is the primary concern in biomedical applications. Micron and nano-scale hydroxyapatite (HA) was coated successfully on MA8M magnesium alloy substrates by using a sol–gel deposition. In this study, the effects of coating thicknesses and HA powder particle sizes on the adhesion strength and corrosion behavior were investigated. Potentiodynamic polarization tests were performed in a Ringer solution. The coatings before and after corrosion tests were characterized by adhesion tests, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The micro-scale-HA coated Mg substrates were more corrosion resistant than the nano-scale-HA coatings. The anodic activity of the micro-scale-HA coatings increased with increased coating thickness and the corrosion resistance of Mg substrates decreased. Corrosion susceptibilities of the nano-scale-HA coated samples were affected inversely. The coated film provided good barrier characteristics and achieved good corrosion protection for Mg substrates when compared to substrates without coatings. For micro-scale-HA coatings, anodic and cathodic activities were more intense for thicker films. When HA coatings are compared to nano-scale HA coatings, the micro-scale-HA coatings produced better current density values. Overall, as shown in Fig. 1, the best corrosion behavior of the Mg alloys was achieved using micro-scale HA powders at 30 μm coating thickness. - Highlights: • Nano and micro-scale-HA coatings provided good anti-corrosion performance compared to the uncoated ones. • The micro-scale-HA coated Mg substrates were more corrosion resistant than the nano-scale-HA coatings. • The best corrosion behavior was achieved for the micro-scale HA powders at 30 μm coating thickness. • Anodic activity decrease and cathodic activity increase with increasing film thickness. - Abstract: To improve the corrosion resistance of MA8M magnesium alloy, sol

  8. Performance of Carbon Coatings for Mitigation of Electron Cloud in the SPS

    CERN Document Server

    Yin Vallgren, C; Costa Pinto, P; Neupert, H; Rumolo, G; Shaposhnikova, E; Taborelli, M; Kato, S

    2011-01-01

    Amorphous carbon (a-C) coatings have been tested in electron cloud monitors (ECM) in the Super Proton Synchrotron (SPS) and have shown for LHC type beams a reduction of the electron cloud current by a factor 104 compared to stainless steel (StSt). This performance has been maintained for more than 3 years under SPS operation conditions. Secondary electron yield (SEY) laboratory data confirm that after more than 1 year of SPS operation, the coating maintains a SEY below 1.0. The compatibility of coexisting StSt and a-C surfaces has been studied in an ECM having coated and uncoated areas. The results show no degradation of the properties of the a-C areas. The performance of diamond like carbon (DLC) coating has also been studied. DLC shows a less effective reduction of the EC current than a-C, but conditioning is faster than for StSt. Three a-C coated dipoles were inserted in the SPS. However, even with no EC detected, the dynamic pressure rise is similar to the one observed in the StSt reference dipoles. Measu...

  9. Synthesis and Performance Evaluation of Pulse Electrodeposited Ni-AlN Nanocomposite Coatings

    Directory of Open Access Journals (Sweden)

    Kamran Ali

    2018-01-01

    Full Text Available This research work presents the microscopic analysis of pulse electrodeposited Ni-AlN nanocomposite coatings using SEM and AFM techniques and their performance evaluation (mechanical and electrochemical by employing nanoindentation and electrochemical methods. The Ni-AlN nanocomposite coatings were developed by pulse electrodeposition. The nickel matrix was reinforced with various amounts of AlN nanoparticles (3, 6, and 9 g/L to develop Ni-AlN nanocomposite coatings. The effect of reinforcement concentration on structure, surface morphology, and mechanical and anticorrosion properties was studied. SEM and AFM analyses indicate that Ni-AlN nanocomposite coatings have dense, homogenous, and well-defined pyramid structure containing uniformly distributed AlN particles. A decent improvement in the corrosion protection performance is also observed by the addition of AlN particles to the nickel matrix. Corrosion current was reduced from 2.15 to 1.29 μA cm−2 by increasing the AlN particles concentration from 3 to 9 g/L. It has been observed that the properties of Ni-AlN nanocomposite coating are sensitive to the concentration of AlN nanoparticles used as reinforcement.

  10. A study on coated particle fuel properties and performances and phase-I data base establishment

    International Nuclear Information System (INIS)

    Kim, Yong Soo; Lee, Hyo Cheol; Im, Byeong Ju; Yun, Sang Pil; Son, Seung Beom; Lee, Gyeong Hui; Jang, Jeong Nam

    2006-03-01

    For the successful development of the high temperature gas cooled reactor acquisition and generation of the high temperature properties of reactor materials, especially temperature and burn-up dependent properties of coated particle fuel and fuel element, are crucially essential. Recently national project for HTGR for hydrogen production has been kicked off. However, we have had little experience on this new challenges. Therefore, it became necessary to build up the materials properties and fuel performance data base. In this study, a primitive properties and performance DB for coated particle fuel was developed. This database report consists two sections: materials properties and fuel performance. The materials properties has three parts: kernel materials, carbide coating materials, and fuel elements and graphite matrix. UO 2 and UCO belong to kernel materials while PyC, SiC, and ZrC comprises the coating materials section. Thermal, mechanical and physical properties of these materials were collected, reviewed, and summarized. Additionally, the property change induced by manufacture process and irradiation were collected and summarized. Performance data were also collected, reviewed, and analyzed based on the key phenomena and failure mechanism. All of these data will be accessible in the on-line system. These results will be directly used for HTGR fuel design and fabrication and preliminary fuel performance analysis under irradiation

  11. Smart Multifunctional Coatings for Corrosion Detection and Control in the Aerospace Industry

    Science.gov (United States)

    Calle, Luz Marina

    2015-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  12. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  13. Tribological performance of an H-DLC coating prepared by PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Solis, J., E-mail: jsolis@ittla.edu.mx [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); SEP/SES/TecNM/IT de Tlalnepantla, DEPI-Mechanical Engineering, 54070, Edo. Méx. (Mexico); Zhao, H.; Wang, C. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); Verduzco, J.A. [Instituto de Investigación en Metalurgia y Materiales, UMSNH, P.O. Box 888, 58000, Morelia, Mich. (Mexico); Bueno, A.S. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom); Mechanical Engineering Department, Universidade Federal de São João Del Rei, 170 Praça Frei Orlando, 36307-352 São João Del Rei (Brazil); Neville, A. [IFS, University of Leeds, School of Mechanical Engineering, Leeds, LS2 9JT (United Kingdom)

    2016-10-15

    Highlights: • Duplex hydrogenated Diamond-like Carbon was produced and characterised. • Friction and wear under dry condition of H-DLC/steel tribopair was assessed. • Adhesive strength of the coating was 80N after the scratch tests under dry condition. • Maximum and minimum values of average coefficient of friction were 0.21 and 0.13. • A protective transferred layer on the counterpart produced a carbon-carbon contact. - Abstract: Carbon-based coatings are of wide interest due to their application in machine elements subjected to continuous contact where fluid lubricant films are not permitted. This paper describes the tribological performance under dry conditions of duplex layered H-DLC coating sequentially deposited by microwave excited plasma enhanced chemical vapour deposition on AISI 52100 steel. The architecture of the coating comprised Cr, WC, and DLC (a-C:H) with a total thickness of 2.8 μm and compressive residual stress very close to 1 GPa. Surface hardness was approximately 22 GPa and its reduced elastic modulus around 180 GPa. Scratch tests indicated a well adhered coating achieving a critical load of 80 N. The effect of normal load on the friction and wear behaviours were investigated with steel pins sliding against the actual coating under dry conditions at room temperature (20 ± 2 °C) and 35–50% RH. The results show that coefficient of friction of the coating decreased from 0.21 to 0.13 values with the increase in the applied loads (10–50 N). Specific wear rates of the surface coating also decrease with the increase in the same range of applied loads. Maximum and minimum values were 14 × 10{sup −8} and 5.5 × 10{sup −8} mm{sup −3}/N m, respectively. Through Raman spectroscopy and electron microscopy it was confirmed the carbon-carbon contact, due to the tribolayer formation on the wear scars of the coating and pin. In order to further corroborate the experimental observations regarding the graphitisation behaviour, the

  14. Fabrication of Polymeric Coatings with Controlled Microtopographies Using an Electrospraying Technique.

    Directory of Open Access Journals (Sweden)

    Qiongyu Guo

    Full Text Available Surface topography of medical implants provides an important biophysical cue on guiding cellular functions at the cell-implant interface. However, few techniques are available to produce polymeric coatings with controlled microtopographies onto surgical implants, especially onto implant devices of small dimension and with complex structures such as drug-eluting stents. Therefore, the main objective of this study was to develop a new strategy to fabricate polymeric coatings using an electrospraying technique based on the uniqueness of this technique in that it can be used to produce a mist of charged droplets with a precise control of their shape and dimension. We hypothesized that this technique would allow facile manipulation of coating morphology by controlling the shape and dimension of electrosprayed droplets. More specifically, we employed the electrospraying technique to coat a layer of biodegradable polyurethane with tailored microtopographies onto commercial coronary stents. The topography of such stent coatings was modulated by controlling the ratio of round to stretched droplets or the ratio of round to crumped droplets under high electric field before deposition. The shape of electrosprayed droplets was governed by the stability of these charged droplets right after ejection or during their flight in the air. Using the electrospraying technique, we achieved conformal polymeric coatings with tailored microtopographies onto conductive surgical implants. The approach offers potential for controlling the surface topography of surgical implant devices to modulate their integration with surrounding tissues.

  15. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances.

    Science.gov (United States)

    Zhang, Xueguang; Zhang, Xudong; He, Wen; Yue, Yuanzheng; Liu, Hong; Ma, Jingyun

    2012-10-18

    We report a simple, inexpensive green biomimetic way for developing the high performance LiFePO(4) for high-power lithium-ion batteries. Biocarbon-coated LiFePO(4) nucleus nanoparticles are synthesized by using yeast cells as both a structural template and a biocarbon source.

  16. Fire performance of fiber board coated with nano kaolin-clay film

    Science.gov (United States)

    Zhijia Liu; John F. Hunt; Zhiyong Cai

    2013-01-01

    Fiberboard is a common interior material used both in China and the United States of America. The increase in demand for interior materials has raised concerns regarding combustibility of the materials. The pyrolysis characteristics of fiber, phenolic resin (PF), and nano kaolin-clay (NK) were investigated using thermogravimetry. The fire performances of samples coated...

  17. Pre-coating of LSCM perovskite with metal catalyst for scalable high performance anodes

    KAUST Repository

    Boulfrad, Samir; Cassidy, Mark; Djurado, Elisabeth; Irvine, John Ts S; Jabbour, Ghassan E.

    2013-01-01

    then dispersed into organic based vehicles to form a screen-printable ink which was deposited and fired to form SOFC anode layers. Electrochemical tests show a considerable enhancement of the pre-coated anode performances under 50 ml/min wet H2 flow

  18. Improving the Performance of Lithium–Sulfur Batteries by Conductive Polymer Coating

    KAUST Repository

    Yang, Yuan; Yu, Guihua; Cha, Judy J.; Wu, Hui; Vosgueritchian, Michael; Yao, Yan; Bao, Zhenan; Cui, Yi

    2011-01-01

    Ah/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li-S batteries and can be applicable to other electrode materials in lithium ion batteries

  19. Improved rate control for electron-beam evaporation and evaluation of optical performance improvements.

    Science.gov (United States)

    Gevelber, Michael; Xu, Bing; Smith, Douglas

    2006-03-01

    A new deposition-rate-control and electron-beam-gun (e-gun) strategy was developed that significantly reduces the growth-rate variations for e-beam-deposited SiO2 coatings. The resulting improvements in optical performance are evaluated for multilayer bandpass filters. The adverse effect of uneven silica-source depletion on coating spectral performances during long deposition runs is discussed.

  20. Performance and Durability of Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

    2016-01-01

    This presentation highlights advanced environmental barrier coating (EBC) and SiC-SiC Ceramic Matrix Composites (CMC) systems for next generation turbine engines. The emphasis will be placed on fundamental coating and CMC property evaluations; and the integrated system performance and degradation mechanisms in simulated laboratory turbine engine testing environments. Long term durability tests in laser rig simulated high heat flux the rmomechanical creep and fatigue loading conditions will also be presented. The results can help improve the future EBC-CMC system designs, validating the advanced EBC-CMC technologies for hot section turbine engine applications.

  1. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    Directory of Open Access Journals (Sweden)

    Mohamed Alburaki

    Full Text Available Thirty-two honeybee (Apis mellifera colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads.

  2. Poly(dimethylsiloxane) coatings for controlled drug release--polymer modifications.

    Science.gov (United States)

    Schulze Nahrup, J; Gao, Z M; Mark, J E; Sakr, A

    2004-02-11

    Modifications of endhydroxylated poly(dimethylsiloxane) (PDMS) formulations were studied for their ability to be applied onto tablet cores in a spray-coating process and to control drug release in zero-order fashion. Modifications of the crosslinker from the most commonly used tetraethylorthosilicate (TEOS) to the trifunctional 3-(2,3-epoxypropoxy)propyltrimethoxysilane (SIG) and a 1:1 mixture of the two were undertaken. Addition of methylpolysiloxane-copolymers were studied. Lactose, microcrystalline cellulose (MCC) and polyethylene glycol 8000 (PEG) were the channeling agents applied. The effects on dispersion properties were characterized by particle size distribution and viscosity. Mechanical properties of resulting free films were studied to determine applicability in a pan-coating process. Release of hydrochlorothiazide (marker drug) was studied from tablets coated in a lab-size conventional coating pan. All dispersions were found suitable for a spray-coating process. Preparation of free films showed that copolymer addition was not possible due to great decline in mechanical properties. Tablets coated with formulations containing PEG were most suitable to control drug release, at only 5% coating weight. Constant release rates could be achieved for formulations with up to 25% PEG; higher amounts resulted in a non-linear release pattern. Upon adding 50% PEG, a drug release of 63% over 24 h could be achieved.

  3. Biocatalytic coatings for air pollution control: a proof of concept study on VOC biodegradation.

    Science.gov (United States)

    Estrada, José M; Bernal, Oscar I; Flickinger, Michael C; Muñoz, Raúl; Deshusses, Marc A

    2015-02-01

    Although biofilm-based biotechnologies exhibit a large potential as solutions for off-gas treatment, the high water content of biofilms often causes pollutant mass transfer limitations, which ultimately limit their widespread application. The present study reports on the proof of concept of the applicability of bioactive latex coatings for air pollution control. Toluene vapors served as a model volatile organic compound (VOC). The results showed that Pseudomonas putida F1 cells could be successfully entrapped in nanoporous latex coatings while preserving their toluene degradation activity. Bioactive latex coatings exhibited toluene specific biodegradation rates 10 times higher than agarose-based biofilms, because the thin coatings were less subject to diffusional mass transfer limitations. Drying and pollutant starvation were identified as key factors inducing a gradual deterioration of the biodegradation capacity in these innovative coatings. This study constitutes the first application of bioactive latex coatings for VOC abatement. These coatings could become promising means for air pollution control. © 2014 Wiley Periodicals, Inc.

  4. Spectral and optical performance of electrochromic poly(3,4-ethylenedioxythiophene) (PEDOT) deposited on transparent conducting oxide coated glass and polymer substrates

    International Nuclear Information System (INIS)

    Sindhu, S.; Narasimha Rao, K.; Ahuja, Sharath; Kumar, Anil; Gopal, E.S.R.

    2006-01-01

    Electrochromic devices utilizing conjugated polymers as electrochromic layers have gained increasing attention owing to their optical properties, fast switching times and contrast ratios. Polyethylenedioxythiophene (PEDOT) is an excellent material from its electrochromic properties, high conductivity and high stability in the doped form. Aqueous dispersions of PEDOT were either spin coated or electro-polymerized on transparent conducting oxide coated glass and polyethylene tetraphthalate (PET) film substrates. The spectro- and opto-electrochemical studies of the films on transparent conducting oxide coated glass/PET substrates were performed. These films have application in the fabrication of electrochromic windows (smart windows). Smart window devices having excellent switching characteristics over wide range of temperature are used for glazing applications. The aerospace industry is interested in the development of visors and windows that can control glare for pilots and passengers, especially if the coatings can be made on curved surfaces and electrically conducting

  5. Effects of Graphene Monolayer Coating on the Optical Performance of Remote Phosphors

    Science.gov (United States)

    Yazdan Mehr, M.; Volgbert, S.; van Driel, W. D.; Zhang, G. Q.

    2017-10-01

    A graphene monolayer has been successfully coated on one side of a bisphenol-A-polycarbonate (BPA-PC) plate, used as a substrate for remote phosphor applications in light-emitting diode (LED)-based products. Using a photoresist transferring method, graphene sheet has been coated on BPA-PC plates. The results show that this graphene monolayer significantly improves the lifetime and performance of LEDs mainly by protecting them against external degradation factors such as moisture and oxygen. Also, LED-based products composed of graphene-coated BPA-PC plates exhibit longer stability with comparatively less loss of luminous efficiency. This method has great potential to significantly improve the reliability of not only LED-based products but also many other microelectronics packaging and components, in which moisture and oxygen are the key causes of failures.

  6. Thermal performance of annular-coated and sphere-pac LWR fuel rod designs

    International Nuclear Information System (INIS)

    Guenther, R.J.; Hsieh, K.A.; Barner, J.O.; Freshley, M.D.

    1980-01-01

    Two FCI-resistant UO 2 fuel rod designs are being compared to a reference design in irradiation tests in the Halden Boiling Water Reactor (HBWR) as part of the DOE-sponsored Fuel Performance Improvement Program (FPIP). The primary fuel design (annular-coated-pressurized) incorporates annular pellets, a graphite coating on the inner surface of the Zircaloy cladding, and pressurized helium fill gas. Also being investigated is an 87% smear density sphere-pac design with pressurized helium fill gas. The solid pellet (reference) and annular-coated designs described had helium fill gas at approx. 100 kPa and the sphere-pac rods were pressurized at approx. 455 kPa

  7. Metal monitoring for process control of laser-based coating removal

    Science.gov (United States)

    Fraser, Mark E.; Hunter, Amy J.; Panagiotou, Thomai; Davis, Steven J.; Freiwald, David A.

    1999-12-01

    Cost-effective and environmentally-sound means of paint and coatings removal is a problem spanning many government, commercial, industrial and municipal applications. For example, the Department of Energy is currently engaged in removing paint and other coatings from concrete and structural steel as part of decommissioning former nuclear processing facilities. Laser-based coatings removal is an attractive new technology for these applications as it promises to reduce the waste volume by up to 75 percent. To function more efficiently, however, the laser-based systems require some form of process control.

  8. Improving the Performance of Lithium–Sulfur Batteries by Conductive Polymer Coating

    KAUST Repository

    Yang, Yuan

    2011-11-22

    Rechargeable lithium-sulfur (Li-S) batteries hold great potential for next-generation high-performance energy storage systems because of their high theoretical specific energy, low materials cost, and environmental safety. One of the major obstacles for its commercialization is the rapid capacity fading due to polysulfide dissolution and uncontrolled redeposition. Various porous carbon structures have been used to improve the performance of Li-S batteries, as polysulfides could be trapped inside the carbon matrix. However, polysulfides still diffuse out for a prolonged time if there is no effective capping layer surrounding the carbon/sulfur particles. Here we explore the application of conducting polymer to minimize the diffusion of polysulfides out of the mesoporous carbon matrix by coating poly(3,4-ethylenedioxythiophene)- poly(styrene sulfonate) (PEDOT:PSS) onto mesoporous carbon/sulfur particles. After surface coating, coulomb efficiency of the sulfur electrode was improved from 93% to 97%, and capacity decay was reduced from 40%/100 cycles to 15%/100 cycles. Moreover, the discharge capacity with the polymer coating was ∼10% higher than the bare counterpart, with an initial discharge capacity of 1140 mAh/g and a stable discharge capacity of >600 mAh/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li-S batteries and can be applicable to other electrode materials in lithium ion batteries. © 2011 American Chemical Society.

  9. Actual problems of ultrasonic control of welded anticorrosion coatings (ch. 1)

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Razygraev, N.P.; Runov, A.E.; Sobolev, Yu.A.; Kretov, E.F.; Tabakma, R.L.

    1988-01-01

    Results of investigations into heat treatment effect on the size of discontinuities revealed under ultrasonic control (USC) of welded anticorrosion coatings are presented. Comparison of dimensions of equivalent area of allowable and non-allowable reflector-discantinuities (defectiveness standards) in the alloying zone of melted anticorrosion coatings and bimetal sheet, applied in NPP equipment, is given. It is shown that USC on the side of basic metal monifest almost by an order more defects than USC on the side of melting surface

  10. Simple roll coater with variable coating and temperature control for printed polymer solar cells

    DEFF Research Database (Denmark)

    Dam, Henrik Friis; Krebs, Frederik C

    2012-01-01

    of solution, enabling roll coating testing of new polymers where only small amounts are often available. We demonstrate the formation of >50 solar cells (each with an active area of 1 cm2) with printed metal back electrodes using as little as 0.1 mL of active layer solution. This approach outperforms spin...... coating with respect to temperature control, ink usage, speed and is directly compatible with industrial processing and upscaling....

  11. A study on properties-performances of coated particle fuel and on-line DB establishment

    International Nuclear Information System (INIS)

    Kim, Yong Soo; Lee, Hyo Cheol; Jang, Jeong Nam; Kwon, Seok Hwan

    2007-03-01

    Recently national project for HTGR for hydrogen production has been kicked off. However, For the successful development of the high temperature gas cooled reactor high temperature and burn-up dependent properties of the reactor materials are essentially and crucially required. Therefore, it was proposed to build up the materials properties and fuel performance data base. In this study, a phase - 1 properties and performance DB for coated particle fuel was developed. This database report consists two sections: materials properties and fuel performance. The materials properties has three parts: kernel materials, carbide coating materials, and fuel elements and graphite matrix. UO2 and UCO belong to kernel materials while PyC, SiC, and ZrC comprises the coating materials section. Thermal, mechanical and physical properties data of these materials were collected, reviewed, and summarized. Additionally, the property change induced by manufacture process and irradiation were reviewed. Fuel performance data were also collected, reviewed, and analyzed based on the key phenomena and failure mechanism, These performance data are divided into two: normal and accident. All of these data will be accessible in the pc based stand-alone system. These results will be directly used for HTGR fuel design and fabrication and preliminary fuel performance analysis under irradiation

  12. Cutting Performance of Low Stress Thick TiAlN PVD Coatings during Machining of Compacted Graphite Cast Iron (CGI

    Directory of Open Access Journals (Sweden)

    Kenji Yamamoto

    2018-01-01

    Full Text Available A new family of physical vapor deposited (PVD coatings is presented in this paper. These coatings are deposited by a superfine cathode (SFC using the arc method. They combine a smooth surface, high hardness, and low residual stresses. This allows the production of PVD coatings as thick as 15 µm. In some applications, in particular for machining of such hard to cut material as compacted graphite iron (CGI, such coatings have shown better tool life compared to the conventional PVD coatings that have a lower thickness in the range of up to 5 μm. Finite element modeling of the temperature/stress profiles was done for the SFC coatings to present the temperature/stress profiles during cutting. Comprehensive characterization of the coatings was performed using XRD, TEM, SEM/EDS studies, nano-hardness, nano-impact measurements, and residual stress measurements. Application of the coating with this set of characteristics reduces the intensity of buildup edge formation during turning of CGI, leading to longer tool life. Optimization of the TiAlN-based coatings composition (Ti/Al ratio, architecture (mono vs. multilayer, and thickness were performed. Application of the optimized coating resulted in a 40–60% improvement in the cutting tool life under finishing turning of CGI.

  13. Size-Controlled Dissolution of Organic-Coated Silver Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Rui; Levard, Clément; Marinakos, Stella M.; Cheng, Yingwen; Liu, Jie; Michel, F. Marc; Brown, Jr., Gordon E.; Lowry, Gregory V. (Duke)

    2012-04-02

    The solubility of Ag NPs can affect their toxicity and persistence in the environment. We measured the solubility of organic-coated silver nanoparticles (Ag NPs) having particle diameters ranging from 5 to 80 nm that were synthesized using various methods, and with different organic polymer coatings including poly(vinylpyrrolidone) and gum arabic. The size and morphology of Ag NPs were characterized by transmission electron microscopy (TEM). X-ray absorption fine structure (XAFS) spectroscopy and synchrotron-based total X-ray scattering and pair distribution function (PDF) analysis were used to determine the local structure around Ag and evaluate changes in crystal lattice parameters and structure as a function of NP size. Ag NP solubility dispersed in 1 mM NaHCO{sub 3} at pH 8 was found to be well correlated with particle size based on the distribution of measured TEM sizes as predicted by the modified Kelvin equation. Solubility of Ag NPs was not affected by the synthesis method and coating as much as by their size. Based on the modified Kelvin equation, the surface tension of Ag NPs was found to be {approx}1 J/m{sup 2}, which is expected for bulk fcc (face centered cubic) silver. Analysis of XAFS, X-ray scattering, and PDFs confirm that the lattice parameter, {alpha}, of the fcc crystal structure of Ag NPs did not change with particle size for Ag NPs as small as 6 nm, indicating the absence of lattice strain. These results are consistent with the finding that Ag NP solubility can be estimated based on TEM-derived particle size using the modified Kelvin equation for particles in the size range of 5-40 nm in diameter.

  14. Oxidation performance of high temperature steels and coatings for future supercritical power plants

    Energy Technology Data Exchange (ETDEWEB)

    Auerkari, Pertti; Salonen, Jorma; Toivonen, Aki; Penttilae, Sami [VTT, Espoo (Finland); Haekkilae, Juha [Foster Wheeler Energia, Varkaus (Finland); Aguero, Alina; Gutierrez, Marcos; Muelas, Raul [INTA, Madrid (Spain); Fry, Tony [NPL (United Kingdom)

    2010-07-01

    The operating efficiency of current and future thermal power plants is largely dependent on the applied temperature and pressure, which are in part limited by the internal oxidation resistance of the structural materials in the steam systems. Alternative and reference materials for such systems have been tested within the COST 536 (ACCEPT) project, including bulk reference materials (ferritic P92 and austenitic 316 LN steels) and several types of coatings under supercritical combined (oxygen) water chemistry (150 ppb DO) at 650 C/300 bar. The testing results from a circulating USC autoclave showed that under such conditions the reference bulk steels performed poorly, with extensive oxidation already after relatively short term exposure to the supercritical medium. Better protection was attained by suitable coatings, although there were clear differences in the protective capabilities between different coating types, and some challenges remain in applying (and repairing) coatings for the internal surfaces of welded structures. The materials performance seems to be worse in supercritical than in subcritical conditions, and this appears not to be only due to the effect of temperature. The implications are considered from the point of view of the operating conditions and materials selection for future power plants. (orig.)

  15. COMPARATIVE PERFORMANCE OF COATED AND UNCOATED INSERTS DURING INTERMITTENT CUT MILLING OF AISI 4340 STEEL

    Directory of Open Access Journals (Sweden)

    SARAVANAN L.

    2015-05-01

    Full Text Available Machining behaviour of TiN coated and uncoated cemented carbide tools were studied during intermittent milling operation of AISI 4340 steel. Series of orthogonal intermittent milling tests were performed subsequently to investigate the role of the selected tools and cutting parameters. Three cutting parameters namely cutting speed, feed and depth of cut with three different levels and two types of cutting tools (coated and uncoated were considered for conducting the experimental trials. Intermittent face milling was employed to study the wear behaviour of the tools and the resulting surface roughness. The cyclic load induced during the entry and exit of the tool, leads to unstable temperature at cutting zone. This unstable temperature affects the tool life badly during intermittent milling. Tool wear increases considerably with an increase in frequency of the interruption. The experimental results indicated that the coated tool out performed uncoated tool in terms of tool life and surface finish. The other interesting observation was the uncoated tool performed better than coated tool at moderate cutting parameters. Results also indicated that the fracture and chipping were the dominant tool failure modes in uncoated tool. The chipping of uncoated tool causes the surface quality to deteriorate. TiN coating ensures the toughness of the cutting tool, which leads to good surface quality during the machining process. A detailed analysis of tool wear and surface roughness was done and the results are employed to create a linear regression model. This model established the relation between the cutting parameters and the response variables. ANOVA was used to identify the influential parameters which affect the tool wear and surface roughness.

  16. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings

    International Nuclear Information System (INIS)

    Farmer, J C; Haslam, J J; Wong, F; Ji, X; Day, S D; Branagan, D J; Marshall, M C; Meacham, B E; Buffa, E J; Blue, C A; Rivard, J K; Beardsley, M B; Weaver, D T; Aprigliano, L F; Kohler, L; Bayles, R; Lemieux, E J; Wolejsza, T M; Martin, F J; Yang, N; Lucadamo, G; Perepezko, J H; Hildal, K; Kaufman, L; Heuer, A H; Ernst, F; Michal, G M; Kahn, H; Lavernia, E J

    2004-01-01

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an ''integral drip shield'' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  17. Plasma effects on the passive external thermal control coating of Space Station Freedom

    Science.gov (United States)

    Carruth, Ralph, Jr.; Vaughn, Jason A.; Holt, James M.; Werp, Richard; Sudduth, Richard D.

    1992-01-01

    The current baseline chromic acid anodized thermal control coating on 6061-T6 aluminum meteoroid debris (M/D) shields for SSF has been evaluated. The degradation of the solar absorptance, alpha, and the thermal emittance, epsilon, of chromic acid anodized aluminum due to dielectric breakdown in plasma was measured to predict the on-orbit lifetime of the SSF M/D shields. The lifetime of the thermal control coating was based on the surface temperatures achieved with degradation of the thermal control properties, alpha and epsilon. The temperatures of each M/D shield from first element launch (FEL) through FEL+15 years were analyzed. It is shown that the baseline thermal control coating cannot withstand the -140 V potential between the conductive structure of the SSF and the current plasma environment.

  18. Performing instrumentation and controls upgrades

    International Nuclear Information System (INIS)

    Kessler, F. M.; Connell, T. J.; Ryan, M. P.

    1992-01-01

    I and C upgrades are comprised of a varying range of content, complexity, expansiveness, and criticality. There are common threads in all upgrades which can be simplified by the development of a long term I and C upgrade plan. The development of a such a plan can establish effective ground rules for upgrades, large and small. It can be the basis from which to begin an upgrade evaluation and the standard which is used to compare the degree of compliance of any upgrade regarding the plan or to define the differences from the plan and an individual upgrade. Primary motivation for I and C upgrades are obsolescence and unavailability of spare parts. Numerous other areas of consideration are also involved in an upgrade. Today's technology results in most upgrades largely or totally utilizing digital equipment. The use of digital equipment is fairly new in many I and C applications and requires an elaborate evaluation from functional, qualification, operational, and licensing perspectives as well as others. A well defined upgrade plan developed as a basis for I and C upgrades is a significant start to ensuring an effective upgrade process. Properly developed and implemented, the plan will support I and C upgrade efforts to ensure that the intricacies associated with such tasks eliminate the existing problems which require the upgrade to be performed. The upgrade plan also results in ensuring the maximum benefit from all perspectives of the plant enhancements being carried out and considered for future implementation. Instrumentation and controls aging and replacement are issues of growing importance due to the potential for significant impact on plant operation and efficiency. Obsolescence and unavailability of spare parts are major drivers towards evaluating the cost benefits of upgrading current equipment. In addition to these two primary factors, the advantages of utilizing digital equipment have also become of prime importance when evaluating instrumentation and

  19. Study on coated layer material performance of coated particle fuel FBR (2). High temperature property and capability of coating to thick layer of TiN

    International Nuclear Information System (INIS)

    Naganuma, Masayuki; Mizuno, Tomoyasu

    2002-08-01

    'Helium Gas Cooled Coated Particle Fuel FBR' is one of attractive core concepts in the Feasibility Study on Commercialized Fast Reactor Cycle System in Japan, and the design study is presently proceeded. As one of key technologies of this concept, the coated layer material is important, and ceramics is considered to be a candidate material because of the superior refractory. Based on existing knowledge, TiN is regarded to be a possible candidate material, to which some property tests and evaluations have been conducted. In this study, preliminary tests about the high temperature property and the capability of thick layer coating of TiN have been conducted. Results of these tests come to the following conclusions. Heating tests of two kinds of TiN layer specimens coated by PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) were conducted. As a result, as for CVD coating specimens, remarkable charge was not observed on the layer up to 2,000degC, therefore we concluded that the layer by CVD had applicability up to high temperature of actual operation level. On the other hand, as for PVD coating specimens, an unstable behavior that the layer changed to a mesh like texture was observed on a 2,000degC heated specimen, therefore the applied PVD method is not considered to be promising as the coating technique. The surface conditions of some parts inside CVD device were investigated in order to evaluate possibility of TiN thick coating (∼100 μm). As a result, around 500 μm of TiN coating layer was observed on the condition of multilayer. Therefore, we conclude that CVD has capability of coating up to thick layer in actual coated particle fuel fabrication. (author)

  20. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  1. Amplified photoacoustic performance and enhanced photothermal stability of reduced graphene oxide coated gold nanorods for sensitive photoacoustic imaging.

    Science.gov (United States)

    Moon, Hyungwon; Kumar, Dinesh; Kim, Haemin; Sim, Changbeom; Chang, Jin-Ho; Kim, Jung-Mu; Kim, Hyuncheol; Lim, Dong-Kwon

    2015-03-24

    We report a strongly amplified photoacoustic (PA) performance of the new functional hybrid material composed of reduced graphene oxide and gold nanorods. Due to the excellent NIR light absorption properties of the reduced graphene oxide coated gold nanorods (r-GO-AuNRs) and highly efficient heat transfer process through the reduced graphene oxide layer, r-GO-AuNRs exhibit excellent photothermal stability and significantly higher photoacoustic amplitudes than those of bare-AuNRs, nonreduced graphene oxide coated AuNRs (GO-AuNRs), or silica-coated AuNR, as demonstrated in both in vitro and in vivo systems. The linear response of PA amplitude from reduced state controlled GO on AuNR indicates the critical role of GO for a strong photothermal effect of r-GO-AuNRs. Theoretical studies with finite-element-method lab-based simulation reveal that a 4 times higher magnitude of the enhanced electromagnetic field around r-GO-AuNRs can be generated compared with bare AuNRs or GO-AuNRs. Furthermore, the r-GO-AuNRs are expected to be a promising deep-tissue imaging probe because of extraordinarily high PA amplitudes in the 4-11 MHz operating frequency of an ultrasound transducer. Therefore, the r-GO-AuNRs can be a useful imaging probe for highly sensitive photoacoustic images and NIR sensitive therapeutics based on a strong photothermal effect.

  2. Spectral and Wavefront Error Performance of WFIRST-AFTA Bandpass Filter Coating Prototypes

    Science.gov (United States)

    Quijada, Manuel A.; Seide, Laurie; Pasquale, Bert A.; McMann, Joseph C.; Hagopian, John G.; Dominguez, Margaret Z.; Gong, Quian; Marx, Catherine T.

    2016-01-01

    The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflected/transmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the wide-field channel in the WFIRST/AFTA observatory.

  3. Microstructure, composition and performance of PVD coatings designed for successful dry high speed milling

    International Nuclear Information System (INIS)

    Muenz, W.-D.; Lembke, M.I.; Lewis, D.B.; Smith, I.J.

    2001-01-01

    Dry high speed machining (HSM), particularly dry high speed milling, demands hard coatings, which exhibit high toughness, high oxidation resistance, a limited amount of residual stress and excellent adhesion to the cemented carbide (CC) substrate. These requirements are met by TiAICrYN coatings grown by the combined cathodic arc/unbalanced magnetron deposition method. Fully sufficient adhesion is achieved by ion implantation of Cr into the CC prior deposition. Residual stress is controlled by an Y - free base layer; high oxidation resistance is provided by an Y - containing 3 μm thick hard coating with 29 GPa hardness and a residual stress well below -7 GPa. Under the influence of temperatures above 800 o C, Y segregates along the columns of TiAIN and plugs the in/out diffusion of elements. A top layer of Y - containing oxynitride reduces the friction against the work piece material (0.9 to 0.65). Cutting tools coated as such may be used for dry milling up to 25 k rpm in steels HRC > 60. (author)

  4. Effect of cathodic current density on performance of tungsten coatings on molybdenum prepared by electrodeposition in molten salt

    Science.gov (United States)

    Jiang, Fan

    2016-02-01

    Smooth tungsten coatings were prepared at current density below 70 mA cm-2 by electrodeposition on molybdenum substrate from Na2WO4-WO3 -melt at 1173 K in air atmosphere. As the current density reached up to 90 mA cm-2, many significant nodules were observed on the surface of the coating. Surface characterization, microstructure and mechanical properties were performed on the tungsten coatings. As the increasing of current density, the preferred orientation of the coatings changed to (2 0 0). All coatings exhibited columnar-grained-crystalline. There was about a 2 μm thick diffusion layer between tungsten coating and molybdenum substrate. The bending test revealed the tungsten coating had -good bonding strength with the molybdenum substrate. There is a down trend of the grain size of the coating on molybdenum as the current density increased from 30 mA cm-2 to 50 mA cm-2. The coating obtained at 50 mA cm-2 had a minimum grain size of 4.57 μm, while the microhardness of this coating reached to a maximum value of 495 HV.

  5. Development of Electrodeposited Zn/nano-TiO2 Composite Coatings with Enhanced Corrosion Performance

    Science.gov (United States)

    Benea, L.; Dănăilă, E.

    2017-06-01

    Pure zinc coatings have been found ineffective when are used in aggressive environments such as those which contain chlorides or industrial pollutants [1]. In this paper, Zn/nano-TiO2 composite coatings with various contents of TiO2 nanoparticles (diameter size of 10 nm) were prepared on low-carbon steel by electro-codeposition technique. The deposition was carried out at different cathodic potentials ranging from -1600 mV to -2100 mV for different deposition times between 5-15 min. Pure Zn coatings were also produced under the same experimental conditions for comparison. Present work aims to investigate the effects of selected electrodeposition parameters (cathodic potential, TiO2 nanoparticle concentration in the plating bath and electrodeposition time) on the corrosion behavior of electrodeposited Zn/nano-TiO2 composite obtained. The corrosion experiments were performed in natural seawater, using electrochemical methods such as open circuit potential, potentiodynamic polarization and linear polarization resistance. The results showed that the inclusion of TiO2 nanoparticles into zinc matrix lead to an improved corrosion resistance comparatively with pure zinc coatings obtained under similar conditions.

  6. Thermal performance of glass fiber reinforced intumescent fire retardant coating for structural applications

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Ullah, Sami; Aziz, Hammad, E-mail: engr.hammad.aziz03@gmail.com; Omar, Nor Sharifah [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 31750 Perak (Malaysia)

    2015-07-22

    The results of influence of glass fiber addition into the basic intumescent coating formulation towards the enhancement of its thermal insulation properties are presented. The intumescent coatings were formulated from expandable graphite, ammonium polyphosphate, melamine, boric acid, bisphenol A epoxy resin BE-188, polyamide amine H-2310 hardener and fiberglass (FG) of length 3.0 mm. Eight intumescent formulations were developed and the samples were tested for their fire performance by burning them at 450°C, 650°C and 850°C in the furnace for two hours. The effects of each fire test at different temperatures; low and high temperature were evaluated. Scanning Electron Microscope, X-Ray Diffraction technique and Thermo Gravimetric Analysis were conducted on the samples to study the morphology, the chemical components of char and the residual weight of the coatings. The formulation, FG08 containing 7.0 wt% glass fiber provided better results with enhanced thermal insulation properties of the coatings.

  7. Pre-coating of LSCM perovskite with metal catalyst for scalable high performance anodes

    KAUST Repository

    Boulfrad, Samir

    2013-07-01

    In this work, a highly scalable technique is proposed as an alternative to the lab-scale impregnation method. LSCM-CGO powders were pre-coated with 5 wt% of Ni from nitrates. After appropriate mixing and adequate heat treatment, coated powders were then dispersed into organic based vehicles to form a screen-printable ink which was deposited and fired to form SOFC anode layers. Electrochemical tests show a considerable enhancement of the pre-coated anode performances under 50 ml/min wet H2 flow with polarization resistance decreased from about 0.60cm2 to 0.38 cm2 at 900 C and from 6.70 cm2 to 1.37 cm2 at 700 C. This is most likely due to the pre-coating process resulting in nano-scaled Ni particles with two typical sizes; from 50 to 200 nm and from 10 to 40 nm. Converging indications suggest that the latter type of particle comes from solid state solution of Ni in LSCM phase under oxidizing conditions and exsolution as nanoparticles under reducing atmospheres. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  8. Effects of fixture rotation on coating uniformity for high-performance optical filter fabrication

    Science.gov (United States)

    Rubin, Binyamin; George, Jason; Singhal, Riju

    2018-04-01

    Coating uniformity is critical in fabricating high-performance optical filters by various vacuum deposition methods. Simple and planetary rotation systems with shadow masks are used to achieve the required uniformity [J. B. Oliver and D. Talbot, Appl. Optics 45, 13, 3097 (2006); O. Lyngnes, K. Kraus, A. Ode and T. Erguder, in `Method for Designing Coating Thickness Uniformity Shadow Masks for Deposition Systems with a Planetary Fixture', 2014 Technical Conference Proceedings, Optical Coatings, August 13, 2014, DOI: 10.14332/svc14.proc.1817.]. In this work, we discuss the effect of rotation pattern and speed on thickness uniformity in an ion beam sputter deposition system. Numerical modeling is used to determine statistical distribution of random thickness errors in coating layers. The relationship between thickness tolerance and production yield are simulated theoretically and demonstrated experimentally. Production yields for different optical filters produced in an ion beam deposition system with planetary rotation are presented. Single-wavelength and broadband optical monitoring systems were used for endpoint monitoring during filter deposition. Limitations of thickness tolerances that can be achieved in systems with planetary rotation are shown. Paths for improving production yield in an ion beam deposition system are described.

  9. Machining of high performance workpiece materials with CBN coated cutting tools

    International Nuclear Information System (INIS)

    Uhlmann, E.; Fuentes, J.A. Oyanedel; Keunecke, M.

    2009-01-01

    The machining of high performance workpiece materials requires significantly harder cutting materials. In hard machining, the early tool wear occurs due to high process forces and temperatures. The hardest known material is the diamond, but steel materials cannot be machined with diamond tools because of the reactivity of iron with carbon. Cubic boron nitride (cBN) is the second hardest of all known materials. The supply of such PcBN indexable inserts, which are only geometrically simple and available, requires several work procedures and is cost-intensive. The development of a cBN coating for cutting tools, combine the advantages of a thin film system and of cBN. Flexible cemented carbide tools, in respect to the geometry can be coated. The cBN films with a thickness of up to 2 μm on cemented carbide substrates show excellent mechanical and physical properties. This paper describes the results of the machining of various workpiece materials in turning and milling operations regarding the tool life, resultant cutting force components and workpiece surface roughness. In turning tests of Inconel 718 and milling tests of chrome steel the high potential of cBN coatings for dry machining was proven. The results of the experiments were compared with common used tool coatings for the hard machining. Additionally, the wear mechanisms adhesion, abrasion, surface fatigue and tribo-oxidation were researched in model wear experiments.

  10. Effect of Montmorillonite Nanogel Composite Fillers on the Protection Performance of Epoxy Coatings on Steel Pipelines.

    Science.gov (United States)

    Atta, Ayman M; El-Saeed, Ashraf M; Al-Lohedan, Hamad A; Wahby, Mohamed

    2017-06-02

    Montmorillonite (MMT) clay mineral is widely used as filler for several organic coatings. Its activity is increased by exfoliation via chemical modification to produce nanomaterials. In the present work, the modification of MMT to form nanogel composites is proposed to increase the dispersion of MMT into epoxy matrices used to fill cracks and holes produced by the curing exotherms of epoxy resins. The dispersion of MMT in epoxy improved both the mechanical and anti-corrosion performance of epoxy coatings in aggressive marine environments. In this respect, the MMT surfaces were chemically modified with different types of 2-acrylamido-2-methyl propane sulfonic acid (AMPS) nanogels using a surfactant-free dispersion polymerization technique. The effect of the chemical structure, nanogel content and the interaction with MMT surfaces on the surface morphology, surface charges and dispersion in the epoxy matrix were investigated for use as nano-filler for epoxy coatings. The modified MMT nanogel epoxy composites showed excellent resistance to mechanical damage and salt spray resistance up to 1000 h. The interaction of MMT nanogel composites with the epoxy matrix and good response of AMPS nanogel to sea water improve their ability to act as self-healing materials for epoxy coatings for steel.

  11. Performance limits of coated particle fuel. Part I. The significance of empirical performance diagrams and mathematical models in fuel development and power reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Graham, L. W.; Hick, H.

    1973-06-15

    This report introduces a general survey of our present knowledge and understanding of coated particle fuel performance. It defines first the reference power reactor conditions and the reference coated particle design on which the survey is centred. It describes then the typical strategy which has been followed in coated particle fuel development by the Dragon Project R & D Branch. Finally it shows the priorities which have governed the time scale and scope of fuel development and of the present review.

  12. Properties and performance of spin-on-glass coatings for the corrosion protection of stainless steels in chloride media

    DEFF Research Database (Denmark)

    Lampert, Felix; Jensen, Annemette H.; Din, Rameez U.

    2018-01-01

    Spin-on-glass deposition was investigated as viable alternative to increase the durability and performance of 316L steel in chloride environment. The buildup of a detrimental interface oxide was prevented by non-oxidative thermal curing of the coatings, which leads to a transformation...... silica. Electrochemical analysis by cyclic polarization indicated that the coatings behave as imperfect barrier coatings, which may enhance the passive properties of the substrates; however, there is still some statistical scatter in the quality of the coatings. While there is a tendency for an increase...... of the upper limit of the breakdown potential, there is also a decrease of the lower limit. It was found that such lower quality coatings showed, in association with substrate defects, unevenly distributed coating flaws, which may act as initiation points of pitting corrosion and decrease the corrosion...

  13. Effect of cathodic current density on performance of tungsten coatings on molybdenum prepared by electrodeposition in molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Fan, E-mail: jiangfan1109@163.com [Department of Materials and Physics, School of Physics and Optoelectronic Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, Nanjing 210044, Jiangsu Province (China); School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 10083 (China)

    2016-02-15

    Graphical abstract: - Highlights: • Tungsten coatings were successfully electroplated on molybdenum substrate. • The electrodeposition was studied in the air atmosphere at 1173 K. • The coating had columnar structure with preferential growth orientation of (2 0 0). • The coating obtained at 50 mA cm{sup −2} had a maximum microhardness of 495 HV. - Abstract: Smooth tungsten coatings were prepared at current density below 70 mA cm{sup −2} by electrodeposition on molybdenum substrate from Na{sub 2}WO{sub 4}-WO{sub 3} -melt at 1173 K in air atmosphere. As the current density reached up to 90 mA cm{sup −2}, many significant nodules were observed on the surface of the coating. Surface characterization, microstructure and mechanical properties were performed on the tungsten coatings. As the increasing of current density, the preferred orientation of the coatings changed to (2 0 0). All coatings exhibited columnar-grained-crystalline. There was about a 2 μm thick diffusion layer between tungsten coating and molybdenum substrate. The bending test revealed the tungsten coating had –good bonding strength with the molybdenum substrate. There is a down trend of the grain size of the coating on molybdenum as the current density increased from 30 mA cm{sup −2} to 50 mA cm{sup −2}. The coating obtained at 50 mA cm{sup −2} had a minimum grain size of 4.57 μm, while the microhardness of this coating reached to a maximum value of 495 HV.

  14. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  15. Controlled Distribution and Clustering of Silver in Ag-DLC Nanocomposite Coatings Using a Hybrid Plasma Approach.

    Science.gov (United States)

    Cloutier, M; Turgeon, S; Busby, Y; Tatoulian, M; Pireaux, J-J; Mantovani, D

    2016-08-17

    Incorporation of selected metallic elements into diamond-like carbon (DLC) has emerged as an innovative approach to add unique functional properties to DLC coatings, thus opening up a range of new potential applications in fields as diverse as sensors, tribology, and biomaterials. However, deposition by plasma techniques of metal-containing DLC coatings with well-defined structural properties and metal distribution is currently hindered by the limited understanding of their growth mechanisms. We report here a silver-incorporated diamond-like carbon coating (Ag-DLC) prepared in a hybrid plasma reactor which allowed independent control of the metal content and the carbon film structure and morphology. Morphological and chemical analyses of Ag-DLC films were performed by atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The vertical distribution of silver from the surface toward the coating bulk was found to be highly inhomogeneous due to top surface segregation and clustering of silver nanoparticles. Two plasma parameters, the sputtered Ag flux and ion energy, were shown to influence the spatial distribution of silver particles. On the basis of these findings, a mechanism for Ag-DLC growth by plasma was proposed.

  16. The Tribological Performance of Hardfaced/ Thermal Sprayed Coatings for Increasing the Wear Resistance of Ventilation Mill Working Parts

    Directory of Open Access Journals (Sweden)

    A. Vencl

    2015-09-01

    Full Text Available During the coal pulverizing, the working parts of the ventilation mill are being worn by the sand particles. For this reason, the working parts are usually protected with materials resistant to wear (hardfaced/thermal sprayed coatings. The aim of this study was to evaluate the tribological performance of four different types of coatings as candidates for wear protection of the mill’s working parts. The coatings were produced by using the filler materials with the following nominal chemical composition: NiFeBSi-WC, NiCrBSiC, FeCrCTiSi, and FeCrNiCSiBMn, and by using the plasma arc welding and flame and electric arc spraying processes. The results showed that Ni-based coatings exhibited higher wear resistance than Fe-based coatings. The highest wear resistance showed coating produced by using the NiFeBSi-WC filler material and plasma transferred arc welding deposition process. The hardness was not the only characteristic that affected the wear resistance. In this context, the wear rate of NiFeBSi-WC coating was not in correlation with its hardness, in contrast to other coatings. The different wear performance of NiFeBSi-WC coating was attributed to the different type and morphological features of the reinforcing particles (WC.

  17. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    Science.gov (United States)

    Patond, S. B.; Chaple, S. A.; Shrirao, P. N.; Shaikh, P. I.

    2013-06-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3·2SiO2 (mullite) (Al2O3 = 60%, SiO2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  18. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    International Nuclear Information System (INIS)

    Patond, S B; Chaple, S A; Shrirao, P N; Shaikh, P I

    2013-01-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al 2 O 3 ·2SiO 2 (mullite) (Al 2 O 3 = 60%, SiO 2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  19. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Science.gov (United States)

    Yu, Honglian; Merib, Josias; Anderson, Jared L

    2016-03-18

    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Influence of load on the dry frictional performance of alkyl acrylate copolymer elastomers coated with diamond-like carbon films

    NARCIS (Netherlands)

    Martinez, D. Martinez; Nohava, Jiri; De Hosson, J. Th. M.

    2015-01-01

    In this work, the influence of applied load on the frictional behavior of alkyl acrylate copolymer elastomers coated with diamond- like carbon films is studied at dry conditions. The performance of two coatings with very different microstructure (patched vs. continuous film) is compared with the

  1. Improvement of Zinc Coating Weight Control for Transition of Target Change

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chien Ming; Lin, Jeong Hwa; Hsu, Tse Wei; Lin, Rui Rong [China Steel Corporation, Kaohsiung (China)

    2010-06-15

    The product specification of the Continuous Hot Dip Galvanizing Line (CGL) changes and varies constantly with different customers' requirements, especially in the zinc coating weight which is from 30 to 150 g/m{sup 2} on each side. Since the coating weight of zinc changes often, it is very important to reduce time spent in the transfer of target values changed for low production cost and yield loss. The No.2 CGL in China Steel Corporation (CSC) has improved the control of the air knife which is designed by Siemens VAI. CSC proposed an experiment design which is an L{sub 9}(3{sup 4}) orthogonal array to find the relations between zinc coating weight and the process parameters, such as the line speed, air pressure, gap of air knife and air knife position. A non-linear regression formula was derived from the experimental results and applied in the mathematical model. A new air knife feedforward control system, which is coupled with the regression formula, the air knife control system and the process computer, is implemented into the line. The practical plant operation results have been presented to show the transfer time is obviously shortened while zinc coating weight target changing and the product rejected ratio caused by zinc coating weight out of specification is significantly reduced from 0.5% to 0.15%.

  2. Synergistic effects of mica and wollastonite fillers on thermal performance of intumescent fire retardant coating

    Energy Technology Data Exchange (ETDEWEB)

    Zia-ul-Mustafa, M., E-mail: engr.ziamustafa@gmail.com; Ahmad, Faiz; Megat-Yusoff, Puteri S. M.; Aziz, Hammad [Mechanical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    In this study, intumescent fire retardant coatings (IFRC) were developed to investigate the synergistic effects of reinforced mica and wollastonite fillers based IFRC towards heat shielding, char expansion, char composition and char morphology. Ammonium poly-phosphate (APP) was used as acid source, expandable graphite (EG) as carbon source, melamine as blowing agent, boric acid as additive and Hardener H-2310 polyamide amine in bisphenol A epoxy resin BE-188(BPA) was used as curing agent. Bunsen burner fire test was used for thermal performance according to UL-94 for 1 h. Field Emission Scanning Electron Microscopy (FESEM) was used to observe char microstructure. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to analyse char composition. The results showed that addition of clay filler in IFRC enhanced the fire protection performance of intumescent coating. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of boron phosphate, silicon phosphate oxide, aluminium borate in the char that improved the thermal performance of intumescent fire retardant coating (IFRC). Resultantly, the presence of these developed compounds enhanced the Integrity of structural steel upto 500°C.

  3. Influence of heat conductivity on the performance of RTV SIR coatings with different fillers

    Energy Technology Data Exchange (ETDEWEB)

    Siderakis, K [High Voltage Laboratory, Department of Electrical and Computer Engineering, University of Patras, GR-26110 Patras (Greece); Agoris, D [High Voltage Laboratory, Department of Electrical and Computer Engineering, University of Patras, Greece, GR-26500, Rion, Greece (Greece); Gubanski, S [High Voltage Laboratory, Department of Electric Power Engineering, Chalmers University of Technology, S-41296, Gothenburg (Sweden)

    2005-10-07

    Room temperature vulcanized silicone rubber (RTV SIR) coatings are employed in order to improve the pollution performance of high voltage ceramic insulators by imparting surface hydrophobicity. In this paper, the performance of three RTV SIR coatings containing different fillers is investigated in a salt-fog test. Alumina trihydrate (ATH) and silica are the fillers included in the formulation, aiming to increase the material endurance to the energy supplied by the surface electrical activity during periods of hydrophobicity loss. The primary action of these fillers is to increase the material heat conductivity, i.e. the amount of energy conducted to the substrate. In addition, in the case of ATH relief is also achieved due to particle decomposition. The results indicate that for the compositions commercially available, where low amounts of fillers are used, and under the conditions of the test, ATH filled coatings performed better than the silica filled ones. This is attributed to ATH decomposition which further relieves the material structure and therefore decelerates material aging.

  4. Controlled protein adsorption on PMOXA/PAA based coatings by thermally induced immobilization

    Science.gov (United States)

    Mumtaz, Fatima; Chen, Chaoshi; Zhu, Haikun; Pan, Chao; Wang, Yanmei

    2018-05-01

    In this work, poly(2-methyl-2-oxazoline-random-glycidyl methacrylate) (PMOXA-r-GMA) and poly(acrylic acid)-block-poly(glycidyl methacrylate) (PAA-b-PGMA) copolymers were synthesized via cationic ring-opening polymerization (CROP) of 2-methyl-2-oxazoline (MOXA) and reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid (AA) followed by their random and block copolymerization with glycidyl methacrylate (GMA), respectively, and then characterized carefully. PMOXA/PAA based coatings were then prepared by simply spin coating the mixture of PMOXA-r-GMA and PAA-b-PGMA copolymer solutions onto silicon/glass substrates followed by annealing at 110 °C. The coatings were rigorously characterized by using X-ray photoelectron spectroscopy (XPS), the static water contact angle (WCA) test, ellipsometry and atomic force microscopy (AFM). The results demonstrated that the coating based mixed PMOXA/PAA brushes with desired surface composition could be attained by simply maintaining their percentage in the mixture of PMOXA-r-GMA and PAA-b-PGMA copolymer solutions. Finally, the switchable behavior of PMOXA/PAA based coatings toward bovine serum albumin (BSA) adsorption was investigated by fluorescein isothiocyanate-labelled BSA (FITC-BSA) assay and quartz crystal microbalance with dissipation monitoring (QCM-D), which indicated that the coating based mixed PMOXA/PAA brushes could control BSA adsorption/desorption from very low to high amount (>90% desorption) through adjusting the composition of PMOXA-r-GMA and PAA-b-PGMA solution used in preparing PMOXA/PAA based coatings upon pH and ionic strength change. Furthermore, PMOXA/PAA based coatings displayed efficient repeatability of reversible BSA adsorption/desorption cycles.

  5. Performance of Nb protective diffusion coating on U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Hyeon; Sohn, Dong-Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Sunghwan; Nam, Ji Min; Lee, Kyu Hong; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    To achieve this aim, it is necessary to increase the volume fraction of fuel particles inside the meat. However, the technical limit is reached at approximately 55 vol.% of fuel particles in the aluminum matrix. As a solution, an uranium compound with an higher uranium density than existing U3Si2 fuel has to be selected. Also alloying the uranium must stabilize γ-phase of uranium at room temperature because adequate properties of the γ -phase of uranium showed a good irradiation behavior in the past. Hence, U-Mo alloys were selected as the best candidates. The formation of interaction phase is a critical problem to apply U-Mo alloys to the high performance research reactor. Different means have been proposed to reduce the interaction between U-Mo fuel and Al matrix. There are three means. : 1. Addition of a diffusion limiting element to the matrix 2. Insertion of a diffusion barrier at the interface between the U-Mo and the Al 3. Alloying of the U-Mo with a third element Here we present the effect of Nb coating as diffusion barrier on formation of interaction layers between UMo powders and Al matrix. We present the effect of Nb coating on formation of interaction layers between U-Mo powders and Al matrix. Centrifugally atomized U-7 wt.% Mo powders were used, and Nb was coated on the surface of U-7 wt.% Mo by sputtering. Subsequently, the Nb-coated U-7 wt.% Mo powders were mixed with pure Al powders, and were made into compacts. The compacts were annealed at 550 .deg. C for 1, 3, 5 hours, respectively, and the result showed that the Nb coating on U-7 wt.% Mo effectively suppressed the growth of interaction layers between U-7 wt.% Mo and Al matrix.

  6. Fabrication and excellent conductive performance of antimony-doped tin oxide-coated diatomite with porous structure

    International Nuclear Information System (INIS)

    Du Yucheng; Yan Jing; Meng Qi; Wang Jinshu; Dai Hongxing

    2012-01-01

    Graphical abstract: Antimony-doped tin oxide (ATO)-coated diatomite with porous structures are fabricated using the co-precipitation method. The porous ATO-coated diatomite material shows excellent conductive performance. Highlights: ► Sb-doped SnO 2 (ATO)-coated diatomite materials with porous structures are prepared. ► Sn/Sb ratio, ATO coating amount, pH value, and temperature influence resistivity. ► Porous ATO-coated diatomite materials show excellent conductive performance. ► The lowest resistivity of the porous ATO-coated diatomite sample is 10 Ω cm. - Abstract: Diatomite materials coated with antimony-doped tin oxide (ATO) were prepared by the co-precipitation method, and characterized by means of the techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, X-ray fluorescence spectroscopy, and N 2 adsorption–desorption measurement. It was shown that the coated ATO possessed a tetragonal rutile crystal structure, and the ATO-coated diatomite materials had a multi-pore (micro- meso-, and macropores) architecture. The porous ATO-coated diatomite materials exhibited excellent electrical conductive behaviors. The best conductive performance (volume resistivity = 10 Ω cm) was achieved for the sample that was prepared under the conditions of Sn/Sb molar ratio = 5.2, Sn/Sb coating amount = 45 wt%, pH = 1.0, and reaction temperature = 50 °C. Such a conductive porous material is useful for the applications in physical and chemical fields.

  7. Fabrication and excellent conductive performance of antimony-doped tin oxide-coated diatomite with porous structure

    Energy Technology Data Exchange (ETDEWEB)

    Du Yucheng, E-mail: ychengdu@bjut.edu.cn [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Yan Jing; Meng Qi; Wang Jinshu [Key Lab of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China); Dai Hongxing, E-mail: hxdai@bjut.edu.cn [Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

    2012-04-16

    Graphical abstract: Antimony-doped tin oxide (ATO)-coated diatomite with porous structures are fabricated using the co-precipitation method. The porous ATO-coated diatomite material shows excellent conductive performance. Highlights: Black-Right-Pointing-Pointer Sb-doped SnO{sub 2} (ATO)-coated diatomite materials with porous structures are prepared. Black-Right-Pointing-Pointer Sn/Sb ratio, ATO coating amount, pH value, and temperature influence resistivity. Black-Right-Pointing-Pointer Porous ATO-coated diatomite materials show excellent conductive performance. Black-Right-Pointing-Pointer The lowest resistivity of the porous ATO-coated diatomite sample is 10 {Omega} cm. - Abstract: Diatomite materials coated with antimony-doped tin oxide (ATO) were prepared by the co-precipitation method, and characterized by means of the techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, X-ray fluorescence spectroscopy, and N{sub 2} adsorption-desorption measurement. It was shown that the coated ATO possessed a tetragonal rutile crystal structure, and the ATO-coated diatomite materials had a multi-pore (micro- meso-, and macropores) architecture. The porous ATO-coated diatomite materials exhibited excellent electrical conductive behaviors. The best conductive performance (volume resistivity = 10 {Omega} cm) was achieved for the sample that was prepared under the conditions of Sn/Sb molar ratio = 5.2, Sn/Sb coating amount = 45 wt%, pH = 1.0, and reaction temperature = 50 Degree-Sign C. Such a conductive porous material is useful for the applications in physical and chemical fields.

  8. Influence of surface morphology and microstructure on performance of CVD tungsten coating under fusion transient thermal loads

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Youyun, E-mail: lianyy@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Liu, Xiang; Wang, Jianbao; Feng, Fan [Southwestern Institute of Physics, Chengdu (China); Lv, Yanwei; Song, Jiupeng [China National R& D Center for Tungsten Technology, Xiamen Tungsten Co. Ltd, 361026 Xiamen (China); Chen, Jiming [Southwestern Institute of Physics, Chengdu (China)

    2016-12-30

    Highlights: • Thick CVD-W coatingswere deposited at a rapid growth rate. • The polished CVD-W coatings have highly textured structure and exhibited a very strong preferred orientation. • The polished CVD tungsten coatings show superior thermal shock resistance as compared with that of the as-deposited coatings. • The crack formation of the polished CVD-W was almost suppressed at an elevated temperature. - Abstract: Thick tungsten coatings have been deposited by chemical vapor deposition (CVD) at a rapid growth rate. A series of tungsten coatings with different thickness and surface morphology were prepared. The surface morphology, microstructure and preferred orientation of the CVD tungsten coatings were investigated. Thermal shock analyses were performed by using an electron beam facility to study the influence of the surface morphology and the microstructure on the thermal shock resistance of the CVD tungsten coatings. Repetitive (100 pulses) ELMs-like thermal shock loads were applied at various temperatures between room temperature and 600 °C with pulse duration of 1 ms and an absorbed power density of up to 1 GW/m{sup 2}. The results of the tests demonstrated that the specific surface morphology and columnar crystal structure of the CVD tungsten have significant influence on the surface cracking threshold and crack propagation of the materials. The CVD tungsten coatings with a polished surface show superior thermal shock resistance as compared with that of the as-deposited coatings with a rough surface.

  9. Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

    Science.gov (United States)

    Wang, Jing; Liu, Song; Qin, Yukun; Chen, Xiaolin; Xing, Rong'e.; Yu, Huahua; Li, Kecheng; Li, Pengcheng

    2017-09-01

    Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization effect and reduce environmental pollution. In this research, we formulated a new double-coated controlled-release fertilizer (CRF) by using food-grade microcrystalline wax (MW) and marine polysaccharide derivatives (calcium alginate and chitosan-glutaraldehyde copolymer). The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW. A convenient and eco-friendly method was used to prepare the CRF. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and composition of the products. The nitrogen-release properties were determined in water using UV-Vis spectrophotometry. The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives. The results show that the double-coated CRFs can release nitrogen in a controlled manner, have excellent controlled-release features, and meet the European Standard for CRFs.

  10. Study of silica coatings degradation under laser irradiation and in controlled environment; Etude de la degradation de couches minces de silice sous flux laser et en environnement controle

    Energy Technology Data Exchange (ETDEWEB)

    Becker, S

    2006-11-15

    Performances of optical components submitted to high laser intensities are usually determined by their laser-induced damage threshold. This value represents the highest density of energy (fluence) sustainable by the component before its damage. When submitted to laser fluences far below this threshold, optical performances may also decrease with time. The degradation processes depend on laser characteristics, optical materials, and environment around the component. Silica being the most used material in optics, the aim of this study was to describe and analyse the physical-chemical mechanisms responsible for laser-induced degradation of silica coatings in controlled environment. Experimental results show that degradation is due to the growth of a carbon deposit in the irradiated zone. From these results, a phenomenological model has been proposed and validated with numerical simulations. Then, several technological solutions have been tested in order to reduce the laser-induced contamination of silica coatings. (author)

  11. Development of high performance electroless Ni-P-HNT composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ranganatha, S., E-mail: kamath.ranganath@gmail.com [Department of studies in chemistry, School of chemical sciences, Kuvempu university, Shankaraghatta-577451, Shimoga, Karnataka (India); Venkatesha, T.V., E-mail: drtvvenkatesha@yahoo.co.uk [Department of studies in chemistry, School of chemical sciences, Kuvempu university, Shankaraghatta-577451, Shimoga, Karnataka (India); Vathsala, K., E-mail: vathsala.mahesh@gmail.com [Nanotribology Laboratory, Mechanical engineering department, Indian Institute of Science, Bangalore 560012, Karnataka (India)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Novel Ni-P composites were prepared by incorporating Halloysite nanotubes. Black-Right-Pointing-Pointer Mild steel specimens surface engineered by nickel using electroless technique. Black-Right-Pointing-Pointer Incorporated halloysite nanotubes made nickel matrix highly corrosion resistant. Black-Right-Pointing-Pointer HNT composite exhibits high hardness and largely reduces friction. - Abstract: Halloysite nanotubes (HNTs) of the dimension 50 nm Multiplication-Sign 1-3 {mu}m (diameter Multiplication-Sign length) are utililized to fabricate the alloy composite by employing electroless/autocatalytic deposition technique. Electroless Ni-P-HNT binary alloy composite coatings are prepared successfully on low carbon steel. These nanotubes were made to get inserted/incorporated into nickel matrix and corresponding composites are examined for their electrochemical, mechanical and tribological performances and compared with that of plain Ni-P. The coatings were characterized using scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDX) techniques to analyze surface nature and composition correspondingly. Small amount of incorporated HNTs made Ni-P deposits appreciable enhancement and betterment in corrosion resistance, hardness and friction resistance. This drastic improvement in the properties reflects the effect of addition of HNTs into Ni-P matrix leading to the development of high performance Ni-P-HNT composite coatings.

  12. Development of high performance electroless Ni–P–HNT composite coatings

    International Nuclear Information System (INIS)

    Ranganatha, S.; Venkatesha, T.V.; Vathsala, K.

    2012-01-01

    Highlights: ► Novel Ni–P composites were prepared by incorporating Halloysite nanotubes. ► Mild steel specimens surface engineered by nickel using electroless technique. ► Incorporated halloysite nanotubes made nickel matrix highly corrosion resistant. ► HNT composite exhibits high hardness and largely reduces friction. - Abstract: Halloysite nanotubes (HNTs) of the dimension 50 nm × 1–3 μm (diameter × length) are utililized to fabricate the alloy composite by employing electroless/autocatalytic deposition technique. Electroless Ni–P–HNT binary alloy composite coatings are prepared successfully on low carbon steel. These nanotubes were made to get inserted/incorporated into nickel matrix and corresponding composites are examined for their electrochemical, mechanical and tribological performances and compared with that of plain Ni–P. The coatings were characterized using scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDX) techniques to analyze surface nature and composition correspondingly. Small amount of incorporated HNTs made Ni–P deposits appreciable enhancement and betterment in corrosion resistance, hardness and friction resistance. This drastic improvement in the properties reflects the effect of addition of HNTs into Ni–P matrix leading to the development of high performance Ni–P–HNT composite coatings.

  13. Dip-Coating Process Engineering and Performance Optimization for Three-State Electrochromic Devices

    Science.gov (United States)

    Wu, Lu; Yang, Dejiang; Fei, Lixun; Huang, Yue; Wu, Fang; Sun, Yiling; Shi, Jiayuan; Xiang, Yong

    2017-06-01

    Titanium dioxide (TiO2) nanoparticles were modified onto fluorine-doped tin oxide (FTO) via dip-coating technique with different nanoparticle sizes, lifting speeds, precursor concentrations, and dipping numbers. Electrodeposition-based electrochromic device with reversible three-state optical transformation (transparent, mirror, and black) was fabricated subsequently by sandwiching a suitable amount of gel electrolyte between modified FTO electrode and flat FTO electrode. Correlation between dip-coating process engineering, morphological features of TiO2 thin films, i.e., thickness and roughness, as well as performance of electrochromic devices, i.e., optical contrast, switching time, and cycling stability, were investigated. The modified device exhibits high optical contrast of 57%, the short coloration/bleaching switching time of 6 and 20 s, and excellent cycling stability after 1500 cycles of only 27% decrement rate by adjusting dip-coating processes engineering. The results in this study will provide valuable guidance for rational design of the electrochromic device with satisfactory performance.

  14. High performance sandwich structured Si thin film anodes with LiPON coating

    Science.gov (United States)

    Luo, Xinyi; Lang, Jialiang; Lv, Shasha; Li, Zhengcao

    2018-04-01

    The sandwich structured silicon thin film anodes with lithium phosphorus oxynitride (LiPON) coating are synthesized via the radio frequency magnetron sputtering method, whereas the thicknesses of both layers are in the nanometer range, i.e. between 50 and 200 nm. In this sandwich structure, the separator simultaneously functions as a flexible substrate, while the LiPON layer is regarded as a protective layer. This sandwich structure combines the advantages of flexible substrate, which can help silicon release the compressive stress, and the LiPON coating, which can provide a stable artificial solidelectrolyte interphase (SEI) film on the electrode. As a result, the silicon anodes are protected well, and the cells exhibit high reversible capacity, excellent cycling stability and good rate capability. All the results demonstrate that this sandwich structure can be a promising option for high performance Si thin film lithium ion batteries.

  15. Monitoring by Control Technique - Compliant (Low/No VOC/HAP) Inks and Coatings

    Science.gov (United States)

    Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about Compliant (Low/No VOC/HAP) Inks and Coatings control techniques used to reduce pollutant emissions.

  16. Photolithography of thick photoresist coating for electrically controlled liquid crystal photonic bandgap fibre devices

    DEFF Research Database (Denmark)

    Wei, Lei; Khomtchenko, Elena; Alkeskjold, Thomas Tanggaard

    2009-01-01

    Thick photoresist coating for electrode patterning in an anisotropically etched V-groove is investigated for electrically controlled liquid crystal photonic bandgap fibre devices. The photoresist step coverage at the convex corners is compared with and without soft baking after photoresist spin...

  17. Hydroxyapatite coatings deposited by liquid precursor plasma spraying: controlled dense and porous microstructures and osteoblastic cell responses

    International Nuclear Information System (INIS)

    Huang Yi; Song Lei; Liu Xiaoguang; Xiao Yanfeng; Wu Yao; Chen Jiyong; Wu Fang; Gu Zhongwei

    2010-01-01

    Hydroxyapatite coatings were deposited on Ti-6Al-4V substrates by a novel plasma spraying process, the liquid precursor plasma spraying (LPPS) process. X-ray diffraction results showed that the coatings obtained by the LPPS process were mainly composed of hydroxyapatite. The LPPS process also showed excellent control on the coating microstructure, and both nearly fully dense and highly porous hydroxyapatite coatings were obtained by simply adjusting the solid content of the hydroxyapatite liquid precursor. Scanning electron microscope observations indicated that the porous hydroxyapatite coatings had pore size in the range of 10-200 μm and an average porosity of 48.26 ± 0.10%. The osteoblastic cell responses to the dense and porous hydroxyapatite coatings were evaluated with human osteoblastic cell MG-63, in respect of the cell morphology, proliferation and differentiation, with the hydroxyapatite coatings deposited by the atmospheric plasma spraying (APS) process as control. The cell experiment results indicated that the heat-treated LPPS coatings with a porous structure showed the best cell proliferation and differentiation among all the hydroxyapatite coatings. Our results suggest that the LPPS process is a promising plasma spraying technique for fabricating hydroxyapatite coatings with a controllable microstructure, which has great potential in bone repair and replacement applications.

  18. Plasma thermal performance of a dual-process PVD/PS tungsten coating on carbon-based panels for nuclear fusion application

    International Nuclear Information System (INIS)

    Kim, Hyunmyung; Lee, Ho Jung; Kim, Sung Hwan; Jang, Changheui

    2016-01-01

    Highlights: • Plasma thermal performance of a dual-process PVD/PS W coating was evaluated. • Steady-state heat fluxes of 1–3 MW/m 2 were applied to the W coated specimens. • Less micro-pores and grain growth were observed for the dual-process coating. • Loss of coating thickness was observed for the simple PS W coating. • Dual-process PVD/PS W coating was resistant to erosion due to the surface PVD layer. - Abstract: Various tungsten (W) coating techniques have been used for the application of plasma facing material in nuclear fusion devices, which resulted in limited success. In this study, a dual-process W coating structure was developed on a graphite substrate to improve the thermal performance of the coating structure. The dual-process coating structure consisted of a thin (∼7 μm) multilayer W/Mo physical vapor deposition (PVD) coating layer deposited on top of the relatively thick (∼160 μm) plasma spray (PS) W coating on a graphite substrate panel. Then the coated sample was exposed to plasma heat flux of 1–3 MW/m 2 for 300 s. With addition of a thin surface PVD coating layer, the microstructure change in underlying PS W coating was substantially reduced compared to the simple PS W coating structure. The thickness of overall coating structure was maintained for the dual-process PVD/PS coated samples after the thermal loading tests, while a significant reduction in thickness due to surface erosion was observed for the simple PS W coated samples. The improvement in surface erosion resistance in the dual-process coating structure was discussed in view of the characteristics of PVD and PS coating layers.

  19. Plasma thermal performance of a dual-process PVD/PS tungsten coating on carbon-based panels for nuclear fusion application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunmyung; Lee, Ho Jung; Kim, Sung Hwan; Jang, Changheui, E-mail: chjang@kaist.ac.kr

    2016-11-01

    Highlights: • Plasma thermal performance of a dual-process PVD/PS W coating was evaluated. • Steady-state heat fluxes of 1–3 MW/m{sup 2} were applied to the W coated specimens. • Less micro-pores and grain growth were observed for the dual-process coating. • Loss of coating thickness was observed for the simple PS W coating. • Dual-process PVD/PS W coating was resistant to erosion due to the surface PVD layer. - Abstract: Various tungsten (W) coating techniques have been used for the application of plasma facing material in nuclear fusion devices, which resulted in limited success. In this study, a dual-process W coating structure was developed on a graphite substrate to improve the thermal performance of the coating structure. The dual-process coating structure consisted of a thin (∼7 μm) multilayer W/Mo physical vapor deposition (PVD) coating layer deposited on top of the relatively thick (∼160 μm) plasma spray (PS) W coating on a graphite substrate panel. Then the coated sample was exposed to plasma heat flux of 1–3 MW/m{sup 2} for 300 s. With addition of a thin surface PVD coating layer, the microstructure change in underlying PS W coating was substantially reduced compared to the simple PS W coating structure. The thickness of overall coating structure was maintained for the dual-process PVD/PS coated samples after the thermal loading tests, while a significant reduction in thickness due to surface erosion was observed for the simple PS W coated samples. The improvement in surface erosion resistance in the dual-process coating structure was discussed in view of the characteristics of PVD and PS coating layers.

  20. Tribological Performance Optimization of Electroless Ni-P-W Coating Using Weighted Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    S. Roy

    2013-12-01

    Full Text Available The present investigation is an experimental approach to deposit electroless Ni-P-W coating on mild steel substrate and find out the optimum combination of various tribological performances on the basis of minimum friction and wear, using weighted principal component analysis (WPCA. In this study three main tribological parameters are chosen viz. load (A, speed (B and time(C. The responses are coefficient of friction and wear depth. Here Weighted Principal Component Analysis (WPCA method is adopted to convert the multi-responses into single performance index called multiple performance index (MPI and Taguchi L27 orthogonal array is used to design the experiment and to find the optimum combination of tribological parameters for minimum coefficient of friction and wear depth. ANOVA is performed to find the significance of the each tribological process parameters and their interactions. The EDX analysis, SEM and XRD are performed to study the composition and structural aspects.

  1. Performance evaluation of Titanium nitride coated tool in turning of mild steel

    Science.gov (United States)

    Srinivas, B.; Pramod Kumar, G.; Cheepu, Muralimohan; Jagadeesh, N.; kumar, K. Ravi; Haribabu, S.

    2018-03-01

    The growth in demand for bio-gradable materials is opened as a venue for using vegetable oils, coconut oils etc., as alternate to the conventional coolants for machining operations. At present in manufacturing industries the demand for surface quality is increasing rapidly along with dimensional accuracy and geometric tolerances. The present study is influence of cutting parameters on the surface roughness during the turning of mild steel with TiN coated carbide tool using groundnut oil and soluble oil as coolants. The results showed vegetable gave closer surface finish compares with soluble oil. Cutting parameters has been optimized with Taguchi technique. In this paper, the main objective is to optimize the cutting parameters and reduce surface roughness analogous to increase the tool life by apply the coating on the carbide inserts. The cost of the coating is more, but economically efficient than changing the tools frequently. The plots were generated and analysed to find the relationship between them which are confirmed by performing a comparison study between the predicted results and theoretical results.

  2. Characterization and antimicrobial performance of nano silver coatings on leather materials

    Directory of Open Access Journals (Sweden)

    N. Lkhagvajav

    2015-03-01

    Full Text Available In this study, the characterization and the antimicrobial properties of nano silver (nAg coating on leather were investigated. For this purpose, turbidity, viscosity and pH of nAg solutions prepared by the sol-gel method were measured. The formation of films from these solutions was characterized according to temperature by Differential Thermal Analysis-Thermogravimetry (DTA-TG equipment. The surface morphology of treated leathers was observed using Scanning Electron Microscopy (SEM. The antimicrobial performance of nAg coatings on leather materials to the test microorganisms as Escherichia coli, Staphylococcus aureus, Candida albicans and Aspergillius niger was evaluated by the application of qualitative (Agar overlay method and quantitative (percentage of microbial reduction tests. According to qualitative test results it was found that 20 μg/cm2 and higher concentrations of nAg on the leather samples were effective against all microorganisms tested. Moreover, quantitative test results showed that leather samples treated with 20 μg/cm2 of nAg demonstrated the highest antibacterial activity against E. coli with 99.25% bacterium removal, whereas a 10 μg/cm2 concentration of nAg on leather was enough to exhibit the excellent percentage reduction against S. aureus of 99.91%. The results are promising for the use of colloidal nano silver solution on lining leather as antimicrobial coating.

  3. Drastically Enhanced High-Rate Performance of Carbon-Coated LiFePO4 Nanorods Using a Green Chemical Vapor Deposition (CVD) Method for Lithium Ion Battery: A Selective Carbon Coating Process.

    Science.gov (United States)

    Tian, Ruiyuan; Liu, Haiqiang; Jiang, Yi; Chen, Jiankun; Tan, Xinghua; Liu, Guangyao; Zhang, Lina; Gu, Xiaohua; Guo, Yanjun; Wang, Hanfu; Sun, Lianfeng; Chu, Weiguo

    2015-06-03

    Application of LiFePO4 (LFP) to large current power supplies is greatly hindered by its poor electrical conductivity (10(-9) S cm(-1)) and sluggish Li+ transport. Carbon coating is considered to be necessary for improving its interparticle electronic conductivity and thus electrochemical performance. Here, we proposed a novel, green, low cost and controllable CVD approach using solid glucose as carbon source which can be extended to most cathode and anode materials in need of carbon coating. Hydrothermally synthesized LFP nanorods with optimized thickness of carbon coated by this recipe are shown to have superb high-rate performance, high energy, and power densities, as well as long high-rate cycle lifetime. For 200 C (18s) charge and discharge, the discharge capacity and voltage are 89.69 mAh g(-1) and 3.030 V, respectively, and the energy and power densities are 271.80 Wh kg(-1) and 54.36 kW kg(-1), respectively. The capacity retention of 93.0%, and the energy and power density retention of 93.6% after 500 cycles at 100 C were achieved. Compared to the conventional carbon coating through direct mixing with glucose (or other organic substances) followed by annealing (DMGA), the carbon phase coated using this CVD recipe is of higher quality and better uniformity. Undoubtedly, this approach enhances significantly the electrochemical performance of high power LFP and thus broadens greatly the prospect of its applications to large current power supplies such as electric and hybrid electric vehicles.

  4. Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture

    Directory of Open Access Journals (Sweden)

    T. Karthikeya Sharma

    2015-11-01

    Full Text Available Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE. This paper investigates the effects of using argon (Ar gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine’s performance within the range studied.

  5. "Thunderstruck": Plasma-Polymer-Coated Porous Silicon Microparticles As a Controlled Drug Delivery System.

    Science.gov (United States)

    McInnes, Steven J P; Michl, Thomas D; Delalat, Bahman; Al-Bataineh, Sameer A; Coad, Bryan R; Vasilev, Krasimir; Griesser, Hans J; Voelcker, Nicolas H

    2016-02-01

    Controlling the release kinetics from a drug carrier is crucial to maintain a drug's therapeutic window. We report the use of biodegradable porous silicon microparticles (pSi MPs) loaded with the anticancer drug camphothecin, followed by a plasma polymer overcoating using a loudspeaker plasma reactor. Homogenous "Teflon-like" coatings were achieved by tumbling the particles by playing AC/DC's song "Thunderstruck". The overcoating resulted in a markedly slower release of the cytotoxic drug, and this effect correlated positively with the plasma polymer coating times, ranging from 2-fold up to more than 100-fold. Ultimately, upon characterizing and verifying pSi MP production, loading, and coating with analytical methods such as time-of-flight secondary ion mass spectrometry, scanning electron microscopy, thermal gravimetry, water contact angle measurements, and fluorescence microscopy, human neuroblastoma cells were challenged with pSi MPs in an in vitro assay, revealing a significant time delay in cell death onset.

  6. Influence of crosslinker structure on performance of functionalised organic-inorganic hybrid sol-gel coating

    Science.gov (United States)

    Vasiljević, J.; Zorko, M.; Štular, D.; Tomšič, B.; Jerman, I.; Orel, B.; Medved, J.; Simončič, B.

    2017-10-01

    This research aimed to investigate the influence of the co-condensation of the three different organofunctional trialkoxysilane precursors with two different crosslinkers, i.e. tetraethoxysilane or organocyclotetrasiloxane on the performance and the washing fastness of this multicomponent multifunctional sol-gel coating on cellulose fibres. To this aim, a three-component equimolar sol mixture (MC), which included 1H,1H,2H,2H-perfluorooctyltriethoxysilane (SiF), 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (SiQ) and P,P-diphenyl-N-(3-(trimethoxysilyl)propyl) phosphinic amide (SiP) in combination with two different concentrations of TEOS (T and 3T) or organocyclotetrasiloxane 2,4,6,8-tetrakis(2-(diethoxy(methyl)silyl)ethyl)-2,4,6,8-tetramethyl-cyclotetrasiloxane (T4) as crosslinkers, was applied to the cotton fibres by a pad-dry-cure process. The functional properties of the coated samples before and after repeated washing were investigated by the water θ (W) and n-hexadecane θ (C16) static contact angle as well as water sliding (roll-off) (α) angle measurements. The inclusion of both TEOS and T4 into the MC sol increased the hydrophobic affect and simultaneously decreased the oleophobic effect of the MC coating. These phenomena were more pronounced for higher concentration of TEOS and T4 crosslinker. The inclusion of T4 into the MC sol improved the coating washing fastness to a significantly higher extent than the inclusion of TEOS, with respect to the applied concentrations.

  7. A Study on Performance Evaluation of Safety-Related Protective Coating for Yonggwang Unit 1 and 2

    International Nuclear Information System (INIS)

    Kim, Sung Young; Kim, Young Bum; Lee, Won Sang

    2010-01-01

    Protective coating inside nuclear power plants could find its origin from NRC Reg. Guide 1.82(Rev. 3) regarding current issue for the regulation of foreign materials inside containment building. The current issue for the regulation of foreign materials inside containment considered/determined the current issues only regarding the blockage of sump screen by foreign materials such as coating material, insulator, and other materials, while safety-related coating is separately managed by NRC Reg. Guide 1.54(Rev. 1). In this study, we performed field walk-down to evaluate the as-is condition of protective coating inside containment building which was classified as for structure and for equipment with applying the requirement for safety-related coating

  8. Effect of Electrochemically Deposited MgO Coating on Printable Perovskite Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    T.A. Nirmal Peiris

    2017-02-01

    Full Text Available Herein, we studied the effect of MgO coating thickness on the performance of printable perovskite solar cells (PSCs by varying the electrodeposition time of Mg(OH2 on the fluorine-doped tin oxide (FTO/TiO2 electrode. Electrodeposited Mg(OH2 in the electrode was confirmed by energy dispersive X-ray (EDX analysis and scanning electron microscopic (SEM images. The performance of printable PSC structures on different deposition times of Mg(OH2 was evaluated on the basis of their photocurrent density-voltage characteristics. The overall results confirmed that the insulating MgO coating has an adverse effect on the photovoltaic performance of the solid state printable PSCs. However, a marginal improvement in the device efficiency was obtained for the device made with the 30 s electrodeposited TiO2 electrode. We believe that this undesirable effect on the photovoltaic performance of the printable PSCs is due to the higher coverage of TiO2 by the insulating MgO layer attained by the electrodeposition technique.

  9. Adsorption performance of titanium dioxide (TiO2) coated air filters for volatile organic compounds.

    Science.gov (United States)

    Zhong, Lexuan; Lee, Chang-Seo; Haghighat, Fariborz

    2012-12-01

    The photocatalytic oxidation (PCO) technology as an alternative method for air purification has been studied for decades and a variety of PCO models indicate that the adsorption of reactants on the catalyst surface is one of the major physical and chemical processes occurring at a heterogeneous photocatalytic reaction. However, limited study explored the adsorption effect of a photocatalyst. This study carried out a systematic evaluation of adsorption performance of titanium dioxide (TiO(2)) coated fiberglass fibers (FGFs), TiO(2) coated carbon cloth fibers (CCFs), and original CCFs air filters at various relative humidity conditions for nine volatile organic compounds. TiO(2)/FGFs, TiO(2)/CCFs, and CCFs were characterized by SEM for morphology and N(2) adsorption isotherm for BET surface area and pore structure. A bench-scale adsorption test setup was constructed and adsorption tests were performed at various relative humidity conditions and four different injected concentrations for each compound. The isothermal adsorption curves at low concentration levels were obtained and they were well described by Langmuir isotherm model. It was noticed that there were significant differences between the adsorption behaviors and photocatalytic activities of TiO(2)/FGFs and TiO(2)/CCFs. It was concluded that adsorption performance is closely related to the characteristics of substrates and therefore, the development of a substrate with high adsorption ability is a promising trend for improving the performance of the UV-PCO technology. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Anticorrosive performance of waterborne epoxy coatings containing water-dispersible hexagonal boron nitride (h-BN) nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Ren, Siming [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Chen, Jia; Liu, Shuan [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhang, Guangan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhao, Haichao, E-mail: zhaohaichao@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Liping, E-mail: wangliping@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xue, Qunji, E-mail: qjxue@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2017-03-01

    Highlights: • Hexagonal boron nitride nanosheets were well dispersed by using water-soluble carboxylated aniline trimer as dispersant. • The best corrosion performance of waterborne epoxy coatings was achieved with the addition of 1 wt% h-BN. • The decrease of the pores and defects of coating matrix inhibits the diffusion and water absorption of corrosive medium in the coating. - Abstract: Homogenous dispersion of hexagonal boron nitride (h-BN) nanosheets in solvents or in the polymer matrix is crucial to initiate their many applications. Here, homogeneous dispersion of hexagonal boron nitride (h-BN) in epoxy matrix was achieved with a water-soluble carboxylated aniline trimer derivative (CAT{sup −}) as a dispersant, which was attributed to the strong π-π interaction between h-BN and CAT{sup −}, as proved by Raman and UV–vis spectra. Transmission electron microscopy (TEM) analysis confirmed a random dispersion of h-BN nanosheets in the waterborne epoxy coatings. The deterioration process of water-borne epoxy coating with and without h-BN nanosheets during the long-term immersion in 3.5 wt% NaCl solution was investigated by electrochemical measurements and water absorption test. Results implied that the introduction of well dispersed h-BN nanosheets into waterborne epoxy system remarkably improved the corrosion protection performance to substrate. Moreover, 1 wt% BN/EP composite coated substrate exhibited higher impedance modulus (1.3 × 10{sup 6} Ω cm{sup 2}) and lower water absorption (4%) than those of pure waterborne epoxy coating coated electrode after long-term immersion in 3.5 wt% NaCl solution, demonstrating its superior anticorrosive performance. This enhanced anticorrosive performance was mainly ascribed to the improved water barrier property of epoxy coating via incorporating homogeneously dispersed h-BN nanosheets.

  11. Remarkable weakness against cleavage stress for YBCO-coated conductors and its effect on the YBCO coil performance

    International Nuclear Information System (INIS)

    Yanagisawa, Y.; Nakagome, H.; Takematsu, T.; Takao, T.; Sato, N.; Takahashi, M.; Maeda, H.

    2011-01-01

    Cleavage strength for YBCO-coated conductor is extremely low, typically 0.5 MPa. The remarkable weakness is due to cracks on the slit edge of the conductor. The cleavage stress appears on YBCO double pancake coils impregnated with epoxy. The cleavage stress should be avoided in the coil winding. Cleavage strength for an YBCO-coated conductor at 77 K was investigated with a model experiment. The nominal cleavage strength for an YBCO-coated conductor is extremely low, typically 0.5 MPa. This low nominal cleavage strength is due to stress concentration on a small part of the YBCO-coated conductor in cleavage fracture. Debonding by the cleavage stress occurs at the interface between the buffer layer and the Hastelloy substrate. The nominal cleavage strength for a slit edge of the conductor is 2.5-times lower than that for the original edge of the conductor; cracks and micro-peel existing over the slit edge reduce the cleavage strength for the slit edge. Cleavage stress and peel stress should be avoided in coil winding, as they easily delaminate the YBCO-coated conductor, resulting in substantial degradation of coil performance. These problems are especially important for epoxy impregnated YBCO-coated conductor coils. It appears that effect of cleavage stress and peel stress are mostly negligible for paraffin impregnated YBCO-coated conductor coils or dry wound YBCO-coated conductor coils.

  12. Slurry Erosion Performance of Ni-Al2O3 Based Thermal-Sprayed Coatings: Effect of Angle of Impingement

    Science.gov (United States)

    Grewal, H. S.; Agrawal, Anupam; Singh, H.; Shollock, B. A.

    2014-02-01

    In this paper, slurry erosion performance of high velocity flame-sprayed Ni-Al2O3 based coatings was evaluated. The coatings were deposited on a hydroturbine steel (CA6NM) by varying the content of Al2O3 in Ni. Using jet-type test rig, erosion behavior of coatings and bare steel was evaluated at different impingement angles. Detailed investigation of the surface morphology of the eroded specimens was undertaken using SEM/EDS to identify potential erosion mechanism. A parameter named "erosion mechanism identifier" (ξ) was used to predict the mode of erosion. It was observed that the coating prepared using 40 wt.% of Al2O3 showed a highest resistance to erosion. This coating enhanced the erosion resistance of the steel by 2 to 4 times. Spalling in the form of splats and chunks of material (formed by interlinking of cracks) along with fracture of Al2O3 splats were identified as primary mechanisms responsible for the loss of coating material. The erosion mechanism of coatings and bare steel predicted by ξ was in good agreement with that observed experimentally. Among different parameters,, a function of fracture toughness ( K IC) and hardness ( H) showed excellent correlation with erosion resistance of coatings at both the impingement angles.

  13. Dutch elm disease control: performance and costs

    Science.gov (United States)

    William N., Jr. Cannon; David P. Worley

    1980-01-01

    Municipal programs to suppress Dutch elm disease have had highly variable results. Performance as measured by tree mortality was unrelated to control strategies. Costs for control programs were 37 to 76 percent less than costs without control programs in the 15-year time-span of the study. Only those municipalities that conducted a high-performance program could be...

  14. Layer-by-Layer-Assembled High-Performance Broadband Antireflection Coatings

    KAUST Repository

    Shimomura, Hiroomi

    2010-03-24

    Nanoparticles are indispensable ingredients of solution-processed optical, dielectric, and catalytic thin films. Although solution-based methods are promising low-cost alternatives to vacuum methods, they can have significant limitations. Coating uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique to make uniform, conformal multistack nanoparticle thin films for optical applications with precise thickness control over each stack. Two particularly sought-after optical applications are broadband antireflection and structural color. The effects of interstack and surface roughness on optical properties of these constructs (e.g., haze and spectral response) have been studied quantitatively using a combination of Fourier-transform methods and atomic force microscopy measurements. Deconvoluting root-mean-square roughness into its large-, intermediate-, and small-scale components enables enhanced optical simulations. A 4-stack broadband antireflection coating (<0.5% average reflectance in the visible range, and 0.2% haze) composed of alternating high-index (n ≈ 1.96) and low-index (n ≈ 1.28) stacks has been made on glass substrate. Films calcinated at 550 °C endure a one-hour-long cloth cleaning test under 100 kPa normal stress. © 2010 American Chemical Society.

  15. Quality control of coated fuel particles for high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Kaneko, Mitsunobu

    1987-01-01

    The quality control of the coated fuel particles for high temperature gas-cooled reactors is characterized by the fact that the size of the target product to be controlled is very small, and the quantity is very large. Accordingly, the sampling plan and the method of evaluating the population through satisfically treating the measured data of the samples are the important subjects to see and evaluate the quality of a batch or a lot. This paper shows the fabrication process and the quality control procedure for the coated fuel particles. The development work of a HTGR was started by Japan Atomic Energy Research Institute in 1969, and as for the production technology for coated fuel particles, Nuclear Fuel Industries, Ltd. has continued the development work. The pilot plan with the capacity of about 40 kg/year was established in 1972. The fuel product fabricated in this plant was put to the irradiation experiment and out-of-pile evaluation test. In 1983, the production capacity was expanded to 200 kg/year, and the fuel compacts for the VHTRC in JAERI were produced for two years. The basic fuel design, the fabrication process, the quality control, the process control and the quality assurance are reported. For the commercial product, the studies from the viewpoint of production and quality control costs are required. (Kako, I.)

  16. Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

    Science.gov (United States)

    Yao, Sun-Hui; Su, Yen-Liang; Lai, Yu-Cheng

    2017-01-01

    Carbonitride (CNx) coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC) coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr) were prepared on biograde AISI 316L stainless steel (SS316L) substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability. PMID:29039782

  17. Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

    Directory of Open Access Journals (Sweden)

    Sun-Hui Yao

    2017-10-01

    Full Text Available Carbonitride (CNx coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr were prepared on biograde AISI 316L stainless steel (SS316L substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability.

  18. Ultrathin nickel hydroxide on carbon coated 3D-porous copper structures for high performance supercapacitors.

    Science.gov (United States)

    Kang, Kyeong-Nam; Kim, Ik-Hee; Ramadoss, Ananthakumar; Kim, Sun-I; Yoon, Jong-Chul; Jang, Ji-Hyun

    2018-01-03

    An ultrathin nickel hydroxide layer electrodeposited on a carbon-coated three-dimensional porous copper structure (3D-C/Cu) is suggested as an additive and binder-free conductive electrode with short electron path distances, large electrochemical active sites, and improved structural stability, for high performance supercapacitors. The 3D-porous copper structure (3D-Cu) provides high electrical conductivity and facilitates electron transport between the Ni(OH) 2 active materials and the current collector of the Ni-plate. A carbon coating was applied to the 3D-Cu to prevent the oxidation of Cu, without degrading the electron transport behavior of the 3D-Cu. The 3D-Ni(OH) 2 /C/Cu exhibited a high specific capacitance of 1860 F g -1 at 1 A g -1 , and good cycling performance, with an 86.5% capacitance retention after 10 000 cycles. When tested in a two-electrode system, an asymmetric supercapacitor exhibited an energy density of 147.9 W h kg -1 and a power density of 37.0 kW kg -1 . These results open a new area of ultrahigh-performance supercapacitors, supported by 3D-Cu electrodes.

  19. Studying the performance of a dehumidifier with adsorbent coated heat exchangers for tropical climate operations

    KAUST Repository

    Oh, Seung Jin; Ng, Kim Choon; Thu, Kyaw; Kum Ja, Marip; Islam, Md Raisul; Chun, Wongee; Chua, Kian Jon Ernest

    2016-01-01

    A solid desiccant dehumidifier equipped with adsorbent coated heat exchangers has been developed and investigated experimentally. The main component of the solid desiccant dehumidifier included two heat exchangers that were coated with silica gel regular density (RD) type powder in order to increase water adsorption uptake by improving its heat transfer. A series of experiment were conducted to evaluate two key performance indices, namely, moisture removal capacity and thermal performance, under various operating conditions. Results revealed that the reduction of dehumidification process time by 50% can lead to significant improvement of the mean humidity ratio at outlet up to 9.3 g/kg. The maximum moisture removal was found to decrease from 14.8 to 13.2 g/kg with higher airflow rates arising from the reduced residence time of the process air. It was further observed that the water moisture removal was highly affected by inlet humidity ratio. In addition, marked improvement in thermal performance can be achieved by a lowered hot water regeneration temperature. Copyright © 2016 ASHRAE

  20. Studying the performance of a dehumidifier with adsorbent coated heat exchangers for tropical climate operations

    KAUST Repository

    Oh, Seung Jin

    2016-09-26

    A solid desiccant dehumidifier equipped with adsorbent coated heat exchangers has been developed and investigated experimentally. The main component of the solid desiccant dehumidifier included two heat exchangers that were coated with silica gel regular density (RD) type powder in order to increase water adsorption uptake by improving its heat transfer. A series of experiment were conducted to evaluate two key performance indices, namely, moisture removal capacity and thermal performance, under various operating conditions. Results revealed that the reduction of dehumidification process time by 50% can lead to significant improvement of the mean humidity ratio at outlet up to 9.3 g/kg. The maximum moisture removal was found to decrease from 14.8 to 13.2 g/kg with higher airflow rates arising from the reduced residence time of the process air. It was further observed that the water moisture removal was highly affected by inlet humidity ratio. In addition, marked improvement in thermal performance can be achieved by a lowered hot water regeneration temperature. Copyright © 2016 ASHRAE

  1. Performance of adsorbent-embedded heat exchangers using binder-coating method

    KAUST Repository

    Li, Ang

    2016-01-01

    The performance of adsorption (AD) chillers or desalination cycles is dictated by the rates of heat and mass transfer of adsorbate in adsorbent-packed beds. Conventional granular-adsorbent, packed in fin-tube heat exchangers, suffered from poor heat transfer in heating (desorption) or cooling (adsorption) processes of the batch-operated cycles, with undesirable performance parameters such as higher footprint of plants, low coefficient of performance (COP) of AD cycles and higher capital cost of the machines. The motivation of present work is to mitigate the heat and mass "bottlenecks" of fin-tube heat exchangers by using a powdered-adsorbent cum binder coated onto the fin surfaces of exchangers. Suitable adsorbent-binder pairs have been identified for the silica gel adsorbent with pore surface areas up to 680 m2/g and pore diameters less than 6 nm. The parent silica gel remains largely unaffected despite being pulverized into fine particles of 100 μm, and yet maintaining its water uptake characteristics. The paper presents an experimental study on the selection and testing processes to achieve high efficacy of adsorbent-binder coated exchangers. The test results indicate 3.4-4.6 folds improvement in heat transfer rates over the conventional granular-packed method, resulting a faster rate of water uptake by 1.5-2 times on the suitable silica gel type. © 2015 Elsevier Ltd. All rights reserved.

  2. Design of coated standing nanowire array solar cell performing beyond the planar efficiency limits

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yang; Ye, Qinghao; Shen, Wenzhong, E-mail: wzshen@sjtu.edu.cn [Institute of Solar Energy, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-05-28

    The single standing nanowire (SNW) solar cells have been proven to perform beyond the planar efficiency limits in both open-circuit voltage and internal quantum efficiency due to the built-in concentration and the shifting of the absorption front. However, the expandability of these nano-scale units to a macro-scale photovoltaic device remains unsolved. The main difficulty lies in the simultaneous preservation of an effective built-in concentration in each unit cell and a broadband high absorption capability of their array. Here, we have provided a detailed theoretical guideline for realizing a macro-scale solar cell that performs furthest beyond the planar limits. The key lies in a complementary design between the light-trapping of the single SNWs and that of the photonic crystal slab formed by the array. By tuning the hybrid HE modes of the SNWs through the thickness of a coaxial dielectric coating, the optimized coated SNW array can sustain an absorption rate over 97.5% for a period as large as 425 nm, which, together with the inherited carrier extraction advantage, leads to a cell efficiency increment of 30% over the planar limit. This work has demonstrated the viability of a large-size solar cell that performs beyond the planar limits.

  3. Effect of triangular texture on the tribological performance of die steel with TiN coatings under lubricated sliding condition

    Science.gov (United States)

    Chen, Ping; Xiang, Xin; Shao, Tianmin; La, Yingqian; Li, Junling

    2016-12-01

    The friction and wear of stamping die surface can affect the service life of stamping die and the quality of stamping products. Surface texturing and surface coating have been widely used to improve the tribological performance of mechanical components. This study experimentally investigated the effect of triangular surface texture on the friction and wear properties of the die steel substrate with TiN coatings under oil lubrication. TiN coatings were deposited on a die steel (50Cr) substrate through a multi-arc ion deposition system, and then triangular surface texturing was fabricated by a laser surface texturing. The friction and wear test was conducted by a UMT-3 pin-on-disk tribometer under different sliding speeds and different applied loads, respectively. The adhesion test was performed to evaluate the effectiveness of triangular texturing on the interfacial bonding strength between the TiN coating and the die steel substrate. Results show that the combination method of surface texturing process and surface coating process has excellent tribological properties (the lowest frictional coefficient and wear volume), compared with the single texturing process or the single coating process. The tribological performance is improved resulting from the high hardness and low elastic modulus of TiN coatings, and the generation of hydrodynamic pressure, function of micro-trap for wear debris and micro-reservoirs for lubricating oil of the triangular surface texture. In addition, the coating bonding strength of the texturing sample is 3.63 MPa, higher than that of the single coating sample (3.48 MPa), but the mechanisms remain to be further researched.

  4. Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

    2012-01-01

    Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

  5. Preliminary evaluation of an aqueous wax emulsion for controlled-release coating.

    Science.gov (United States)

    Walia, P S; Stout, P J; Turton, R

    1998-02-01

    The purpose of this work was to evaluate the use of an aqueous carnauba wax emulsion (Primafresh HS, Johnson Wax) in a spray-coating process. This involved assessing the effectiveness of the wax in sustaining the release of the drug, theophylline. Second, the process by which the drug was released from the wax-coated pellets was modeled. Finally, a method to determine the optimum blend of pellets with different wax thicknesses, in order to yield a zero-order release profile of the drug, was addressed. Nonpareil pellets were loaded with theophylline using a novel powder coating technique. These drug-loaded pellets were then coated with different levels of carnauba wax in a 6-in. diameter Plexiglas fluid bed with a 3.5-in. diameter Wurster partition. Drug release was measured using a spin-filter dissolution device. The study resulted in continuous carnauba wax coatings which showed sustained drug release profile characteristics typical of a barrier-type, diffusion-controlled system. The effect of varying wax thickness on the release profiles was investigated. It was observed that very high wax loadings would be required to achieve long sustained-release times. The diffusion model, developed to predict the release of the drug, showed good agreement with the experimental data. However, the data exhibited an initial lag-time for drug release which could not be predicted a priori based on the wax coating thickness. A method of mixing pellets with different wax thicknesses was proposed as a way to approximate zero-order release.

  6. Control switching in high performance and fault tolerant control

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2010-01-01

    The problem of reliability in high performance control and in fault tolerant control is considered in this paper. A feedback controller architecture for high performance and fault tolerance is considered. The architecture is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization. By usi...

  7. Effects of weathering on performance of intumescent coatings for structure fire protection in the wildland-urban interface

    Science.gov (United States)

    Bahrani, Babak

    The objective of this study was to investigate the effects of weathering on the performance of intumescent fire-retardant coatings on wooden products. The weathering effects included primary (solar irradiation, moisture, and temperature) and secondary (environmental contaminants) parameters at various time intervals. Wildland urban interface (WUI) fires have been an increasing threat to lives and properties. Existing solutions to mitigate the damages caused by WUI fires include protecting the structures from ignition and minimizing the fire spread from one structure to another. These solutions can be divided into two general categories: active fire protection systems and passive fire protection systems. Passive systems are either using pre-applied wetting agents (water, gel, or foam) or adding an extra layer (composite wraps or coatings). Fire-retardant coating treatment methods can be divided into impregnated (penetrant) and intumescent categories. Intumescent coatings are easy to apply, economical, and have a better appearance in comparison to other passive fire protection methods, and are the main focus of this study. There have been limited studies conducted on the application of intumescent coatings on wooden structures and their performance after long-term weathering exposure. The main concerns of weathering effects are: 1) the reduction of ignition resistance of the coating layer after weathering; and 2) the fire properties of coatings after weathering since coatings might contribute as a combustible fuel and assist the fire growth after ignition. Three intumescent coatings were selected and exposed to natural weathering conditions in three different time intervals. Two types of tests were performed on the specimens: a combustibility test consisted of a bench-scale performance evaluation using a Cone Calorimeter, and a thermal decomposition test using Simultaneous Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) method (also known

  8. Delayed condensation and frost formation on superhydrophobic carbon soot coatings by controlling the presence of hydrophilic active sites

    Science.gov (United States)

    Esmeryan, Karekin D.; Castano, Carlos E.; Mohammadi, Reza; Lazarov, Yuliyan; Radeva, Ekaterina I.

    2018-02-01

    Condensation frosting is an undesired natural phenomenon that could be impeded efficiently using appropriate wettability and morphologically patterned surfaces. The icephobic properties of carbon soot and the fabrication scalability of its synthesis method are a good foundation for anti-frosting applications; however, the fundamentals of frost growth and spreading on sooted surfaces have not been examined yet. In this study, we investigate the anti-frosting performance of three groups of superhydrophobic soot coatings by means of 16 MHz quartz crystal microbalances (QCMs). The analysis of the real-time sensor signal of each soot coated QCM pattern shows that frost formation and its propagation velocity depend on the quantity of oxygen functionalities and structural defects in the material. In turn, the reduction of both parameters shifts the onset of frost growth to temperatures below  -20 °C, whereas the interdroplet ice bridging is slowed by a factor of four. Moreover, high-resolution scanning electron micrographs of the samples imply delamination upon defrosting of the soot with spherical-like morphology via polar interactions driven mechanism. These results reveal an opportunity for control of frost incipiency on sooted surfaces by adjusting the synthesis conditions and depositing soot coatings with as low as possible content of hydrophilic active sites.

  9. Synthesis, characterization and electrochemical performance of core/shell structured carbon coated silicon powders for lithium ion battery negative electrodes

    Directory of Open Access Journals (Sweden)

    Tuğrul Çetinkaya

    2017-06-01

    Full Text Available Surface of nano silicon powders were coated with amorphous carbon by pyrolysis of polyacronitrile (PAN polymer. Microstructural characterization of amorphous carbon coated silicon powders (Si-C were carried out using scanning electron microscopy (SEM and thickness of carbon coating is defined by transmission electron microscopy (TEM. Elemental analyses of Si-C powders were performed using energy dispersive X-ray spectroscopy (EDS. Structural and phase characterization of Si-C composite powders were investigated using X-ray diffractometer (XRD and Raman spectroscopy. Produced Si-C powders were prepared as an electrode on the copper current collector and electrochemical tests were carried out using CR2016 button cells at 200 mA/g constant current density. According to electrochemical test results, carbon coating process enhanced the electrochemical performance by reducing the problems stem from volume change and showed 770 mAh/g discharge capacity after 30 cycles.

  10. Temperature controlled infrared broadband cloaking with the bilayer coatings of semiconductor and superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaohua [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Physics and Electronics, Yancheng Teachers University, Yancheng 224051 (China); Liu, Youwen, E-mail: ywliu@nuaa.edu.cn [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Feng, Yuncai [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2015-06-15

    Highlights: • We first propose that the cloak is composed of the bilayer of semiconductor and superconductor. • We realize the infrared broadband cloaking based on the scattering cancellation method. • The cloaking frequency can be tuned by external temperature. - Abstract: The infrared broadband tunable cloaking have been proposed and investigated with the bilayer coating materials of semiconductor (n-Ge) and high-temperature superconductor (YBa{sub 2}Cu{sub 3}O{sub 7}), whose cloaking frequency can be controlled by external temperature. The analytical solution is derived based on the scattering cancellation cloaking technique from the Mie scattering theory, and the full-wave numerical simulation is performed by the finite element method. The calculated and simulated results have demonstrated that this invisibility cloak may reduce the total scattering cross section of the composite structure of 90% over a broad frequency band of nearly 20 THz, and the infrared cloaking frequency can be tuned by the external temperature. It can provide a feasible way to design a broadband tunable cloak.

  11. The erosion performance of particle reinforced metal matrix composite coatings produced by co-deposition cold gas dynamic spraying

    Science.gov (United States)

    Peat, Tom; Galloway, Alexander; Toumpis, Athanasios; McNutt, Philip; Iqbal, Naveed

    2017-02-01

    This work reports on the erosion performance of three particle reinforced metal matrix composite coatings, co-deposited with an aluminium binder via cold-gas dynamic spraying. The deposition of ceramic particles is difficult to achieve with typical cold spray techniques due to the absence of particle deformation. This issue has been overcome in the present study by simultaneously spraying the reinforcing particles with a ductile metallic binder which has led to an increased level of ceramic/cermet particles deposited on the substrate with thick (>400 μm) coatings produced. The aim of this investigation was to evaluate the erosion performance of the co-deposited coatings within a slurry environment. The study also incorporated standard metallographic characterisation techniques to evaluate the distribution of reinforcing particles within the aluminium matrix. All coatings exhibited poorer erosion performance than the uncoated material, both in terms of volume loss and mass loss. The Al2O3 reinforced coating sustained the greatest amount of damage following exposure to the slurry and recorded the greatest volume loss (approx. 2.8 mm3) out of all of the examined coatings. Despite the poor erosion performance, the WC-CoCr reinforced coating demonstrated a considerable hardness increase over the as-received AA5083 (approx. 400%) and also exhibited the smallest free space length between adjacent particles. The findings of this study reveal that the removal of the AA5083 matrix by the impinging silicon carbide particles acts as the primary wear mechanism leading to the degradation of the coating. Analysis of the wear scar has demonstrated that the damage to the soft matrix alloy takes the form of ploughing and scoring which subsequently exposes carbide/oxide particles to the impinging slurry.

  12. Investigation of Dip-Coating Parameters Effect on The Performance of Alumina-Polydimethylsiloxane Nanofiltration Membranes for Desalination

    OpenAIRE

    Mohammad Hadi Yousefi; Mohamad Mehdi Zerafat; Majid Shokri Doodeji; Samad Sabbaghi

    2017-01-01

    The objective of this work is to investigate the effect of dip-coating parameters on the performance of Alumina-PDMS hybrid nanofiltration membranes for water desalination. Ceramic supports used in this work were prepared with a 340 nm average pore size and 34% total porosity. The aim is to determine optimum conditions of dipping time, PDMS concentration, and withdrawal speed in order to achieve high rejection and flux values. Dip-coating parameters were considered as dipping time (60 - 120 s...

  13. Non-contact assessment of electrical performance for rapidly sintered nanoparticle silver coatings through colorimetry

    International Nuclear Information System (INIS)

    Cherrington, M.; Claypole, T.C.; Gethin, D.T.; Worsley, D.A.; Deganello, D.

    2012-01-01

    The color change during the ultrafast near-infrared sintering process of a nanoparticle silver ink has been correlated to its electrical performance through colorimetry using the CIELAB industry standard. Nanoparticle silver ink films, deposited over a flexible polyethylene terephthalate substrate, presented significant shifting in the a* and b* color coordinates during sintering, exhibiting the best conductivity with an a* coordinate of approximately 0 and a b* coordinate of approximately + 10. This color change has been associated with the Lorenz–Mie theory of electromagnetic scattering. This indirect measurement technique is potentially a breakthrough technology for fast in-line non-contact characterization of the drying and sintering process of nanoparticle conductive inks for use in large area roll-to-roll processing of printed electronics. - Highlights: ► Color change of a nanoparticle silver coating was measured during sintering ► Color change was correlated to the electrical performance of the coating. ► Potential in-line non-contact measurement method for roll-to-roll printed electronics

  14. Non-contact assessment of electrical performance for rapidly sintered nanoparticle silver coatings through colorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cherrington, M.; Claypole, T.C.; Gethin, D.T. [Welsh Centre for Printing and Coating, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Worsley, D.A. [SPECIFIC, College of Engineering, Swansea University, Baglan Bay Innovation Centre, Central Avenue, Baglan Energy Park, Port Talbot, SA12 7AX (United Kingdom); Deganello, D., E-mail: d.deganello@swansea.ac.uk [Welsh Centre for Printing and Coating, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)

    2012-11-01

    The color change during the ultrafast near-infrared sintering process of a nanoparticle silver ink has been correlated to its electrical performance through colorimetry using the CIELAB industry standard. Nanoparticle silver ink films, deposited over a flexible polyethylene terephthalate substrate, presented significant shifting in the a* and b* color coordinates during sintering, exhibiting the best conductivity with an a* coordinate of approximately 0 and a b* coordinate of approximately + 10. This color change has been associated with the Lorenz-Mie theory of electromagnetic scattering. This indirect measurement technique is potentially a breakthrough technology for fast in-line non-contact characterization of the drying and sintering process of nanoparticle conductive inks for use in large area roll-to-roll processing of printed electronics. - Highlights: Black-Right-Pointing-Pointer Color change of a nanoparticle silver coating was measured during sintering Black-Right-Pointing-Pointer Color change was correlated to the electrical performance of the coating. Black-Right-Pointing-Pointer Potential in-line non-contact measurement method for roll-to-roll printed electronics.

  15. Prediction of TRISO coated particle performances for a one-pass deep burn

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, Alberto [Nuclear Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL 60439 (United States)], E-mail: alby@anl.gov

    2008-02-15

    In the present studies, TRISO coated particle performances have been investigated for incinerating plutonium and minor actinides by the Gas Turbine-Modular Helium Reactor, whose fresh fuel is fabricated after the uranium extraction (UREX) process applied to Light Water Reactors irradiated fuel. The analyses divide into two parts: in the first part, the latest design of the reactor core proposed by General Atomics, which takes advantage of four fuel rings, has been modeled in deep details by the Monte Carlo MCNP code and a burnup process has been simulated by the MCB code. In the second part, the TRISO coated particle performances have been investigated by the PANAMA code with the goal of verifying the design constraints proposed by General Atomics. During burnup, the refueling and shuffling schedule followed the one-pass deep burn concept, where the fuel is utilized, since fabrication for the Gas Turbine-Modular Helium Reactor, without any reprocessing until the final disposal into the geological repository. During the reactor operation, the fast fluence on all TRISO particles layers has been evaluated and the production of the key fission products monitored. During an hypothetical reactor accident scenario, the TRISO particle failure fraction has been estimated.

  16. Prediction of TRISO coated particle performances for a one-pass deep burn

    International Nuclear Information System (INIS)

    Talamo, Alberto

    2008-01-01

    In the present studies, TRISO coated particle performances have been investigated for incinerating plutonium and minor actinides by the Gas Turbine-Modular Helium Reactor, whose fresh fuel is fabricated after the uranium extraction (UREX) process applied to Light Water Reactors irradiated fuel. The analyses divide into two parts: in the first part, the latest design of the reactor core proposed by General Atomics, which takes advantage of four fuel rings, has been modeled in deep details by the Monte Carlo MCNP code and a burnup process has been simulated by the MCB code. In the second part, the TRISO coated particle performances have been investigated by the PANAMA code with the goal of verifying the design constraints proposed by General Atomics. During burnup, the refueling and shuffling schedule followed the one-pass deep burn concept, where the fuel is utilized, since fabrication for the Gas Turbine-Modular Helium Reactor, without any reprocessing until the final disposal into the geological repository. During the reactor operation, the fast fluence on all TRISO particles layers has been evaluated and the production of the key fission products monitored. During an hypothetical reactor accident scenario, the TRISO particle failure fraction has been estimated

  17. Performance Analysis Review of Thorium TRISO Coated Particles during Manufacture, Irradiation and Accident Condition Heating Tests

    International Nuclear Information System (INIS)

    2015-03-01

    Thorium, in combination with high enriched uranium, was used in all early high temperature reactors (HTRs). Initially, the fuel was contained in a kernel of coated particles. However, particle quality was low in the 1960s and early 1970s. Modern, high quality, tristructural isotropic (TRISO) fuel particles with thorium oxide and uranium dioxide (UO 2 ) had been manufactured since 1978 and were successfully demonstrated in irradiation and accident tests. In 1980, HTR fuels changed to low enriched uranium UO 2 TRISO fuels. The wide ranging development and demonstration programme was successful, and it established a worldwide standard that is still valid today. During the process, results of the thorium work with high quality TRISO fuel particles had not been fully evaluated or documented. This publication collects and presents the information and demonstrates the performance of thorium TRISO fuels.This publication is an outcome of the technical contract awarded under the IAEA Coordinated Research Project on Near Term and Promising Long Term Options for Deployment of Thorium Based Nuclear Energy, initiated in 2012. It is based on the compilation and analysis of available results on thorium TRISO coated particle performance in manufacturing and during irradiation and accident condition heating tests

  18. Thin-Film LSCs Based on PMMA Nanohybrid Coatings: Device Optimization and Outdoor Performance

    Directory of Open Access Journals (Sweden)

    S. M. El-Bashir

    2013-01-01

    Full Text Available This study concerns the design optimization of thin-film luminescent solar concentrators (TLSCs based on polymethylmethacrylate (PMMA/silica nanohybrid films doped with coumarin dyestuffs specialized in coloring plastics. Two designs of TLSCs had been prepared and characterized. The first consists of a transparent nanohybrid layer coated on a fluorescent PMMA substrate. The second design is the ordinary configuration in which fluorescent nanohybrid layer is coated on a transparent PMMA substrate. The investigation of the spectral properties and efficiency parameters recommended the best solar energy conversion efficiency for the second design. The outdoor performance of optimized TLSC was also evaluated under clear sky conditions of Riyadh city, and the hourly values of the optical efficiency, ηopt, were calculated for one year. The best performance was achieved in summer since the short circuit current for PV cell was doubled after being attached to TLSC and the value of ηopt reached 40% which is higher than other values recorded before due to the abundant solar energy potential in the Arabian Peninsula.

  19. Au-coated X-ray Anti-scattering Grid Performance Test by MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Bae, JunWoo; Yoo, Dong Han; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    It is required to protect individual against the dangers of ionizing radiation from medical exposure. And increasing of resolution for x-ray radiography tools can give radiation protectoral benefits. Because the image device has higher resolution in same energy source, it requires low energy level source and it can reduce individual dose. The anti-scattering grid is sub-device that is attached in front of detector (direction of source). It is square lattice shape generally. It is composed of penetration parts and shielding parts. Penetration part is generally air (the void) and in some studies it uses wood or aluminum. Shielding part is composed of various materials such as lead or copper. In this study, it is focused on the gold as one of X-ray grid materials, where gold is generally known as excellent shielding material and the performance test on the gold coated anti-scattering grid is carried out by MCNP simulation. X-ray grid was simulated by using MCNP code and its performance was investigated. It was understood that glass based and Au-coated grid could lessen the scattered photons more where the reduction was about two third. In further study, geometry optimization or material selection will be conducted by MCNP simulation for giving benefits to design proper grid for various instruments.

  20. Human performance interfaces in air traffic control.

    Science.gov (United States)

    Chang, Yu-Hern; Yeh, Chung-Hsing

    2010-01-01

    This paper examines how human performance factors in air traffic control (ATC) affect each other through their mutual interactions. The paper extends the conceptual SHEL model of ergonomics to describe the ATC system as human performance interfaces in which the air traffic controllers interact with other human performance factors including other controllers, software, hardware, environment, and organisation. New research hypotheses about the relationships between human performance interfaces of the system are developed and tested on data collected from air traffic controllers, using structural equation modelling. The research result suggests that organisation influences play a more significant role than individual differences or peer influences on how the controllers interact with the software, hardware, and environment of the ATC system. There are mutual influences between the controller-software, controller-hardware, controller-environment, and controller-organisation interfaces of the ATC system, with the exception of the controller-controller interface. Research findings of this study provide practical insights in managing human performance interfaces of the ATC system in the face of internal or external change, particularly in understanding its possible consequences in relation to the interactions between human performance factors.

  1. Morphology control in thin films of PS:PLA homopolymer blends by dip-coating deposition

    Energy Technology Data Exchange (ETDEWEB)

    Vital, Alexane [Interfaces, Confinement, Matériaux et Nanostructures (ICMN), CNRS-Université d’Orléans, UMR 7374, 1B Rue de la Férollerie, C.S. 40059, 45071 Orléans Cedex 2 (France); Groupe de recherches sur l’énergétique des milieux ionisés (GREMI), CNRS-Université d’Orléans, UMR 7344, 14 rue d' Issoudun, B.P. 6744, F45067 Orléans Cedex 2 (France); Vayer, Marylène [Interfaces, Confinement, Matériaux et Nanostructures (ICMN), CNRS-Université d’Orléans, UMR 7374, 1B Rue de la Férollerie, C.S. 40059, 45071 Orléans Cedex 2 (France); Tillocher, Thomas; Dussart, Rémi [Groupe de recherches sur l’énergétique des milieux ionisés (GREMI), CNRS-Université d’Orléans, UMR 7344, 14 rue d' Issoudun, B.P. 6744, F45067 Orléans Cedex 2 (France); Boufnichel, Mohamed [STMicroelectronics, 16, rue Pierre et Marie Curie, B.P. 7155, 37071 Tours Cedex 2 (France); and others

    2017-01-30

    Highlights: • A process to control the morphology of polymer blends thin film is described. • It is based on the use of dip-coating at various withdrawal speeds. • The process is examined within the capillary and the draining regimes. • The final dried morphology is controlled by the regime of deposition. • This study is of high interest for the preparation of advanced functional surfaces. - Abstract: In this work, smooth polymer films of PS, PLA and their blends, with thicknesses ranging from 20 nm up to 400 nm and very few defects on the surface were obtained by dip-coating. In contrast to the process of spin-coating which is conventionally used to prepare thin films of polymer blends, we showed that depending on the deposition parameters (withdrawal speed and geometry of the reservoir), various morphologies such as layered films and laterally phase-separated domains could be formed for a given blend/solvent pair, offering much more opportunities compared to the spin-coating process. This diversity of morphologies was explained by considering the superposition of different phenomena such as phase separation process, dewetting and vitrification in which parameters such as the drying time, the compatibility of the polymer/solvent pairs and the affinity of the polymer towards the interfaces were suspected to play a significant role. For that purpose, the process of dip-coating was examined within the capillary and the draining regimes (for low and high withdrawal speed respectively) in order to get a full description of the thickness variation and evaporation rate as a function of the deposition parameters.

  2. Anticorrosive performance of waterborne epoxy coatings containing water-dispersible hexagonal boron nitride (h-BN) nanosheets

    Science.gov (United States)

    Cui, Mingjun; Ren, Siming; Chen, Jia; Liu, Shuan; Zhang, Guangan; Zhao, Haichao; Wang, Liping; Xue, Qunji

    2017-03-01

    Homogenous dispersion of hexagonal boron nitride (h-BN) nanosheets in solvents or in the polymer matrix is crucial to initiate their many applications. Here, homogeneous dispersion of hexagonal boron nitride (h-BN) in epoxy matrix was achieved with a water-soluble carboxylated aniline trimer derivative (CAT-) as a dispersant, which was attributed to the strong π-π interaction between h-BN and CAT-, as proved by Raman and UV-vis spectra. Transmission electron microscopy (TEM) analysis confirmed a random dispersion of h-BN nanosheets in the waterborne epoxy coatings. The deterioration process of water-borne epoxy coating with and without h-BN nanosheets during the long-term immersion in 3.5 wt% NaCl solution was investigated by electrochemical measurements and water absorption test. Results implied that the introduction of well dispersed h-BN nanosheets into waterborne epoxy system remarkably improved the corrosion protection performance to substrate. Moreover, 1 wt% BN/EP composite coated substrate exhibited higher impedance modulus (1.3 × 106 Ω cm2) and lower water absorption (4%) than those of pure waterborne epoxy coating coated electrode after long-term immersion in 3.5 wt% NaCl solution, demonstrating its superior anticorrosive performance. This enhanced anticorrosive performance was mainly ascribed to the improved water barrier property of epoxy coating via incorporating homogeneously dispersed h-BN nanosheets.

  3. Tribological Performance of Hydrogenated Amorphous Carbon (a-C: H DLC Coating when Lubricated with Biodegradable Vegetal Canola Oil

    Directory of Open Access Journals (Sweden)

    H.M. Mobarak

    2014-06-01

    Full Text Available Increasing environmental awareness and demands for lowering energy consumptions are strong driving forces behind the development of the vehicles of tomorrow. Without the advances of lubricant chemistry and adequate lubricant formulation, expansion of modern engines would not have been possible. Considering environmental awareness factors as compared to mineral oils, vegetal oil based biolubricants are renewable, biodegradable, non-toxic and have a least amount of greenhouse gases. Furthermore, improvement in engine performance and transmission components, which were impossible to achieve by applying only lubricants design, is now possible through diamond like carbon (DLC coatings. DLC coatings exhibit brilliant tribological properties, such as good wear resistance and low friction. In this regard, tribological performance of a-C: H DLC coating when lubricated with Canola vegetal oil has been investigated by the help of a ball-on-flat geometry. Experimental results demonstrated that the a-C: H DLC coating exhibited better performance with Canola oil in terms of friction and wear as compared to the uncoated materials. Large amount of polar components in the Canola oil significantly improved the tribological properties of the a-C:H coating. Thus, usage of a-C: H DLC coating with Canola oil in the long run may have a positive impact on engine life.

  4. Bio-Sustainable Control of the Blue Stain Fungi Aureobasidium pullulans on Exterior Wood Coatings

    DEFF Research Database (Denmark)

    Stenbæk, Jonas

    on the coating has been studied. In this study, manipulation of the micro structure on the coating surface has been performed and revealed that small scratches-structure (between 4-20 μm) had an inhibitory effect on the attachment on fungal conidia from moulds while bigger structure scratches (>50 μm) did...

  5. Analyses of performance of novel sensors with different coatings for detection of Lipopolysaccharide

    KAUST Repository

    Mohd. Syaifudin, A. R.; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Matias, Ignacio R.; Goicoechea, J.; Kosel, Jü rgen; Gooneratne, Chinthaka Pasan

    2011-01-01

    Interdigital sensors have been widely used for non-destructive applications. New types of planar interdigital sensors have been fabricated with different coating materials to assess the response to Lipopolysaccharide, LPS. All the coatings were

  6. Electrically controlled drug release from nanostructured polypyrrole coated on titanium

    International Nuclear Information System (INIS)

    Sirivisoot, Sirinrath; Pareta, Rajesh; Webster, Thomas J

    2011-01-01

    Previous studies have demonstrated that multi-walled carbon nanotubes grown out of anodized nanotubular titanium (MWNT-Ti) can be used as a sensing electrode for various biomedical applications; such sensors detected the redox reactions of certain molecules, specifically proteins deposited by osteoblasts during extracellular matrix bone formation. Since it is known that polypyrrole (PPy) can release drugs upon electrical stimulation, in this study antibiotics (penicillin/streptomycin, P/S) or an anti-inflammatory drug (dexamethasone, Dex), termed PPy[P/S] or PPy[Dex], respectively, were electrodeposited in PPy on titanium. The objective of the present study was to determine if such drugs can be released from PPy on demand and (by applying a voltage) control cellular behavior important for orthopedic applications. Results showed that PPy films possessed nanometer-scale roughness as analyzed by atomic force microscopy. X-ray photoelectron spectroscopy confirmed the presence of P/S and Dex encapsulated within the PPy films. Results from cyclic voltammetry showed that 80% of the drugs were released on demand when sweep voltages were applied for five cycles at a scan rate of 0.1 V s -1 . Furthermore, osteoblast (bone-forming cells) and fibroblast (fibrous tissue-forming cells) adhesion were determined on the PPy films. Results showed that PPy[Dex] enhanced osteoblast adhesion after 4 h of culture compared to plain Ti. PPy-Ti (with or without anionic drug doping) inhibited fibroblast adhesion compared to plain Ti. These in vitro results confirmed that electrodeposited PPy[P/S] and PPy[Dex] can release drugs on demand to potentially fight bacterial infection, reduce inflammation, promote bone growth or reduce fibroblast functions, further implicating the use of such materials as implant sensors.

  7. Electrically controlled drug release from nanostructured polypyrrole coated on titanium

    Science.gov (United States)

    Sirivisoot, Sirinrath; Pareta, Rajesh; Webster, Thomas J.

    2011-02-01

    Previous studies have demonstrated that multi-walled carbon nanotubes grown out of anodized nanotubular titanium (MWNT-Ti) can be used as a sensing electrode for various biomedical applications; such sensors detected the redox reactions of certain molecules, specifically proteins deposited by osteoblasts during extracellular matrix bone formation. Since it is known that polypyrrole (PPy) can release drugs upon electrical stimulation, in this study antibiotics (penicillin/streptomycin, P/S) or an anti-inflammatory drug (dexamethasone, Dex), termed PPy[P/S] or PPy[Dex], respectively, were electrodeposited in PPy on titanium. The objective of the present study was to determine if such drugs can be released from PPy on demand and (by applying a voltage) control cellular behavior important for orthopedic applications. Results showed that PPy films possessed nanometer-scale roughness as analyzed by atomic force microscopy. X-ray photoelectron spectroscopy confirmed the presence of P/S and Dex encapsulated within the PPy films. Results from cyclic voltammetry showed that 80% of the drugs were released on demand when sweep voltages were applied for five cycles at a scan rate of 0.1 V s - 1. Furthermore, osteoblast (bone-forming cells) and fibroblast (fibrous tissue-forming cells) adhesion were determined on the PPy films. Results showed that PPy[Dex] enhanced osteoblast adhesion after 4 h of culture compared to plain Ti. PPy-Ti (with or without anionic drug doping) inhibited fibroblast adhesion compared to plain Ti. These in vitro results confirmed that electrodeposited PPy[P/S] and PPy[Dex] can release drugs on demand to potentially fight bacterial infection, reduce inflammation, promote bone growth or reduce fibroblast functions, further implicating the use of such materials as implant sensors.

  8. Electrically controlled drug release from nanostructured polypyrrole coated on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Sirivisoot, Sirinrath; Pareta, Rajesh; Webster, Thomas J, E-mail: Thomas_Webster@Brown.edu [School of Engineering, Brown University, Providence, RI 02912 (United States)

    2011-02-25

    Previous studies have demonstrated that multi-walled carbon nanotubes grown out of anodized nanotubular titanium (MWNT-Ti) can be used as a sensing electrode for various biomedical applications; such sensors detected the redox reactions of certain molecules, specifically proteins deposited by osteoblasts during extracellular matrix bone formation. Since it is known that polypyrrole (PPy) can release drugs upon electrical stimulation, in this study antibiotics (penicillin/streptomycin, P/S) or an anti-inflammatory drug (dexamethasone, Dex), termed PPy[P/S] or PPy[Dex], respectively, were electrodeposited in PPy on titanium. The objective of the present study was to determine if such drugs can be released from PPy on demand and (by applying a voltage) control cellular behavior important for orthopedic applications. Results showed that PPy films possessed nanometer-scale roughness as analyzed by atomic force microscopy. X-ray photoelectron spectroscopy confirmed the presence of P/S and Dex encapsulated within the PPy films. Results from cyclic voltammetry showed that 80% of the drugs were released on demand when sweep voltages were applied for five cycles at a scan rate of 0.1 V s{sup -1}. Furthermore, osteoblast (bone-forming cells) and fibroblast (fibrous tissue-forming cells) adhesion were determined on the PPy films. Results showed that PPy[Dex] enhanced osteoblast adhesion after 4 h of culture compared to plain Ti. PPy-Ti (with or without anionic drug doping) inhibited fibroblast adhesion compared to plain Ti. These in vitro results confirmed that electrodeposited PPy[P/S] and PPy[Dex] can release drugs on demand to potentially fight bacterial infection, reduce inflammation, promote bone growth or reduce fibroblast functions, further implicating the use of such materials as implant sensors.

  9. Investigation of phase-change coatings for variable thermal control of spacecraft

    Science.gov (United States)

    Kelliher, W. C.; Young, P. R.

    1972-01-01

    An investigation was conducted to determine the feasibility of producing a spacecraft coating system that could vary the ratio of its solar absorptance to thermal emittance to adjust automatically for changes in the thermal balance of a spacecraft. This study resulted in a new concept called the phase-change effect which uses the change that occurs in the optical properties of many materials during the phase transition from a crystalline solid to an amorphous material. A series of two-component model coatings was developed which, when placed on a highly reflecting substrate, exhibited a sharp decrease in solar absorptance within a narrow temperature range. A variable thermal control coating can have a significant amount of temperature regulation with the phase-change effect. Data are presented on several crystallite-polymer formulations, their physical and optical properties, and associated phase-change temperatures. Aspects pertaining to their use in a space environment and an example of the degree of thermal regulation attainable with these coatings is also given.

  10. Micro-Structures and High-Temperature Friction-Wear Performances of Laser Cladded Cr–Ni Coatings

    Directory of Open Access Journals (Sweden)

    Li Jiahong

    2018-01-01

    Full Text Available Cr–Ni coatings with the mass ratios of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni were fabricated on H13 hot work mould steel using a laser cladding (LC. The surface–interface morphologies, chemical elements, surface roughness and phase composition of the obtained Cr–Ni coatings were analysed using a scanning electron microscope (SEM, energy disperse spectroscopy (EDS, atomic force microscope (AFM and X–ray diffractometer (XRD, respectively. The friction–wear properties and wear rates of Cr–Ni coatings with the different mass ratios of Cr and Ni at 600 °C were investigated, and the worn morphologies and wear mechanism of Cr–Ni coatings were analysed. The results show that the phases of Cr–Ni coatings with mass ratios of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni are composed of Cr + Ni single-phases and their compounds at the different stoichiometry, the porosities on the Cr–Ni coatings increase with the Cr content increasing. The average coefficient of friction (COF of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% coatings are 1.10, 0.33 and 0.87, respectively, in which the average COF of 20% Cr–80% Ni coating is the lowest, exhibiting the better anti-friction performance. The wear rate of 17% Cr–83% Ni, 20% Cr–80% Ni and 24% Cr–76% Ni coatings is 4.533 × 10−6, 5.433 × 10−6, and 1.761 × 10−6 N−1·s−1, respectively, showing the wear resistance of Cr–Ni coatings at a high temperature increases with the Cr content, in which the wear rate is 24% Cr–76% Ni coating with the better reducing wear. The wear mechanism of 17% Cr–83% Ni and 20% Cr–80% Ni and 24% Cr–76% coatings at 600 °C is primarily adhesive wear, and that of 24% Cr–76% coating is also accompanied by oxidative wear.

  11. Coatings and surface treatments for enhanced performance suspensions for future gravitational wave detectors

    Science.gov (United States)

    Birney, R.; Cumming, A. V.; Campsie, P.; Gibson, D.; Hammond, G. D.; Hough, J.; Martin, I. W.; Reid, S.; Rowan, S.; Song, S.; Talbot, C.; Vine, D.; Wallace, G.

    2017-12-01

    Further improvements in the low frequency sensitivity of gravitational wave detectors are important for increasing the observable population of astrophysical sources, such as intermediate mass compact black hole binary systems. Improvements in the lower stage mirror and suspension systems will set challenging targets for the required thermal noise performance of the cantilever blade springs, which provide vertical softness and, thus, isolation to the mirror suspension stack. This is required due to the coupling between the vertical and horizontal axes due to the curvature of the Earth. This can be achieved through use of high mechanical Q materials, which are compatible with cryogenic cooling, such as crystalline silicon. However, such materials are brittle, posing further challenges for assembly/jointing and, more generally, for long-term robustness. Here, we report on experimental studies of the breaking strength of silicon at room temperature, via both tensile and 4-point flexural testing; and on the effects of various surface treatments and coatings on durability and strength. Single- and multi-layer DLC (diamond-like carbon) coatings, together with magnetron-sputtered silica and thermally-grown silica, are investigated, as are the effects of substrate preparation and argon plasma pre-treatment. Application of single- or multi-layer DLC coatings can significantly improve the failure stress of silicon flexures, in addition to improved robustness for handling (assessed through abrasion tests). Improvements of up to 80% in tensile strength, a twofold increase in flexural strength, in addition to a 6.4 times reduction in the vertical thermal noise contribution of the suspension stack at 10 Hz are reported (compared to current Advanced LIGO design). The use of silicon blade springs would also significantly reduce potential ‘crackling noise’ associated with the underlying discrete events associated with plastic deformation in loaded flexures.

  12. Irradiated-Microsphere Gamma Analyzer (IMGA): an integrated system for HTGR coated particle fuel performance assessment

    International Nuclear Information System (INIS)

    Kania, M.J.; Valentine, K.H.

    1980-02-01

    The Irradiated-Microsphere Gamma Analyzer (IMGA) System, designed and built at ORNL, provides the capability of making statistically accurate failure fraction measurements on irradiated HTGR coated particle fuel. The IMGA records the gamma-ray energy spectra from fuel particles and performs quantitative analyses on these spectra; then, using chemical and physical properties of the gamma emitters it makes a failed-nonfailed decision concerning the ability of the coatings to retain fission products. Actual retention characteristics for the coatings are determined by measuring activity ratios for certain gamma emitters such as 137 Cs/ 95 Zr and 144 Ce/ 95 Zr for metallic fission product retention and 134 Cs/ 137 Cs for an indirect measure of gaseous fission product retention. Data from IMGA (which can be put in the form of n failures observed in N examinations) can be accurately described by the binomial probability distribution model. Using this model, a mathematical relationship between IMGA data (n,N), failure fraction, and confidence level was developed. To determine failure fractions of less than or equal to 1% at confidence levels near 95%, this model dictates that from several hundred to several thousand particles must be examined. The automated particle handler of the IMGA system provides this capability. As a demonstration of failure fraction determination, fuel rod C-3-1 from the OF-2 irradiation capsule was analyzed and failure fraction statistics were applied. Results showed that at the 1% failure fraction level, with a 95% confidence level, the fissile particle batch could not meet requirements; however, the fertile particle exceeded these requirements for the given irradiation temperature and burnup

  13. The effects of carbon coating on the electrochemical performances of ZnO in Ni–Zn secondary batteries

    International Nuclear Information System (INIS)

    Long, Wei; Yang, Zhanhong; Fan, Xinming; Yang, Bin; Zhao, Zhiyuan; Jing, Jing

    2013-01-01

    The ZnO samples coated with carbon are successfully synthesized by using a high energy ball milling method. The scanning electron microscopy (SEM) images and energy dispersive spectrometer (EDS) spectra of the carbon-coated ZnO and pure ZnO show that the carbon-coated ZnO (carbon source: glucose, citric acid) samples and the untreated ZnO sample have similar particle size and crystal form. The particles have prismatic microstructure whose sizes are about 100–200 nm. However, the carbon-coated ZnO (carbon source: sucrose) sample has become agglomeration after calcination whose size has been increased to 2–6 μm. The uncoated ZnO powders have more complete crystal shape and they are glazed quadrangular materials, while the carbon coated ZnO particles has a rough surface, which resulted from the growth of carbon coating on ZnO particles. X-ray diffraction (XRD) patterns of the carbon-coated ZnO and the pure ZnO show carbon formed on the surface of ZnO is amorphous. Tafel plot, cyclic voltammetry (CV), AC impedance spectroscopy and galvanostatic charge–discharge measurement are utilized to examine the electrochemical performances of the carbon-coated ZnO. The carbon-coated ZnO (carbon source: glucose) have the most positive steady-state potential and lowest corrosion current density in the zinc electrodes which indicates that it has a good anticorrosion ability. A lower charge platform and a higher discharge platform of carbon-coated ZnO indicate that it have a better charge/discharge performance as anodic material for Ni/Zn cells. A smaller ohmic resistance and charge-transfer resistance imply that the carbon film upon ZnO could greatly decrease the impedance of the reaction process. Meanwhile, the carbon-coated ZnO also showed more excellent cycling performance than pure ZnO. The reason of improvement about electrochemical performance can be ascribed as the unique structure of amorphous carbon layer

  14. Replication performance of Si-N-DLC-coated Si micro-molds in micro-hot-embossing

    International Nuclear Information System (INIS)

    Saha, B; Tor, S B; Liu, E; Khun, N W; Hardt, D E; Chun, J H

    2010-01-01

    Micro-hot-embossing is an emerging technology with great potential to form micro- and nano-scale patterns into polymers with high throughput and low cost. Despite its rapid progress, there are still challenges when this technology is employed, as demolding stress is usually very high due to large friction and adhesive forces induced during the process. Surface forces are dominating parameters in micro- and nano-fabrication technologies because of a high surface-to-volume ratio of products. This work attempted to improve the surface properties of Si micro-molds by means of silicon- and nitrogen-doped diamond-like carbon (Si-N-DLC) coatings deposited by dc magnetron cosputtering on the molds. The bonding structure, surface roughness, surface energy, adhesive strength and tribological behavior of the coated samples were characterized with micro Raman spectroscopy, atomic force microscopy (AFM), contact angle measurement, microscratch test and ball-on-disk sliding tribological test, respectively. It was observed that the doping condition had a great effect on the performance of the coatings. The Si-N-DLC coating deposited with 5 × 10 −6 m 3 min −1 N 2 had lowest surface roughness and energy of about 1.2 nm and 38.2 × 10 −3 N m −1 , respectively, while the coatings deposited with 20 × 10 −6 and 25 × 10 −6 m 3 min −1 N 2 showed lowest friction coefficients. The uncoated and Si-N-DLC-coated Si micro-molds were tested in a micro-hot-embossing process for a comparative study of their replication performance and lifetime. The experimental results showed that the performance of the Si micro-molds was improved by the Si-N-DLC coatings, and well-defined micro-features with a height of about 100 µm were fabricated successfully into cyclic olefin copolymer (COC) sheets using the Si-N-DLC-coated micro-molds.

  15. Black molecular adsorber coatings for spaceflight applications

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

    2014-09-01

    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  16. Thermal Performance Study of Composite Phase Change Material with Polyacrylicand Conformal Coating.

    Science.gov (United States)

    Kee, Shin Yiing; Munusamy, Yamuna; Ong, Kok Seng; Cornelis Metselaar, Hendrik Simon; Chee, Swee Yong; Lai, Koon Chun

    2017-07-28

    The composite PCM was prepared by blending polymethyl methacrylate (PMMA) and myristic acid (MA) in different weight percentages. The MA and PMMA were selected as PCM and supporting material, respectively. As liquid MA may leak out during the phase transition, this study proposes the use of two coatings, namely a polyacrylic coating and a conformal coating to overcome the leakage problem. Both coatings were studied in terms of the leakage test, chemical compatibility, thermal stability, morphology, and reliability. No leakage was found in the PCMs with coatings compared to those without under the same proportions of MA/PMMA, thus justifying the use of coatings in the present study. The chemically compatibility was confirmed by FTIR spectra: the functional groups of PCMs were in accordance with those of coatings. DSC showed that the coatings did not significantly change the melting and freezing temperatures, however, they improved the thermal stability of composite PCMs as seen in TGA analysis. Furthermore, the composite PCMs demonstrated good thermal reliability after 1000 times thermal cycling. The latent heat of melting reduced by only 0.16% and 1.02% for the PCMs coated with conformal coating and polyacrylic coating, respectively. Therefore, the proposed coatings can be considered in preparing fatty acid/PMMA blends attributed to the good stability, compatibility and leakage prevention.

  17. Design and performance evaluation of the functional coating for air purification under indoor conditions

    NARCIS (Netherlands)

    Lorencik, S.; Yu, Q.L.; Brouwers, H.J.H.

    2015-01-01

    The present work aims to develop a photocatalytic coating for the improvement of indoor air quality. Two types of visible-light responsive photocatalysts (powder and suspension form) were applied into a water-based acrylic coating. The applied materials were characterized and the developed coatings

  18. Porous Hierarchical Nitrogen-doped Carbon Coated ZnFe_2O_4 Composites as High Performance Anode Materials for Lithium Ion Batteries

    International Nuclear Information System (INIS)

    Yue, Hongyun; Wang, Qiuxian; Shi, Zhenpu; Ma, Chao; Ding, Yanmin; Huo, Ningning; Zhang, Jun; Yang, Shuting

    2015-01-01

    Porous hierarchical and nitrogen-doped carbon coated ZnFe_2O_4 (ZnFe_2O_4@NC) was obtained by combustion method and unique carbon coating technology. Gum Arabic was firstly introduced in the carbon coating process as an additive, which played an important role to control the uniformity of carbon coating layer. The nitrogen-doped carbon layer was obtained through the pyrolysis of glycine. The elemental composition and content of the nitrogen-doped carbon in composites were characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and thermal gravimetric analysis (TGA). The galvanostatic charge/discharge cycling was used to test the electrochemical performance of ZnFe_2O_4@NC and pure ZnFe_2O_4. The sub-micro size ZnFe_2O_4@NC with unique porous structure showed an excellent electrochemical performance as an anode material, which was higher than that of pure ZnFe_2O_4. ZnFe_2O_4@NC could maintain the specific discharge capacity of 1477 mAh g"−"1 at 0.1 A g"−"1 after 100 cycles and 705 mAh g"−"1 at 1 A g"−"1 after 1000 cycles, respectively.

  19. Enhancement of isobutane refrigerator performance by using far-infrared coating

    International Nuclear Information System (INIS)

    Hsu, Yu-Chun; Teng, Tun-Ping

    2016-01-01

    Highlights: • Two-step synthesis method was employed to produce FIRCs. • Emissivity of FIRCs was determined using a FT-IR. • The highest emissivity of FIRMs was MWCNT. • No-load pull-down and 24-h on-load cycling test were performed. • The COP and EF of S2 were greater than those of S1 by 5.92% and 7.89%. - Abstract: This study evaluated the effect on refrigeration performance and feasibility of a far-infrared coating (FIRC) on the condenser of a small isobutane (R-600a) refrigerator. The evaluation was based on the no-load pull-down and 24-h on-load cycling tests. Far-infrared materials and a water-based coating material were mixed using a two-step synthesis method to obtain the FIRC material. Fourier transform infrared spectrometry established that the optimal far-infrared material was a multiwalled carbon nanotube (MWCNT). The results of the no-load pull-down test revealed that the electricity consumption, freezer temperature, and coefficient of performance (COP) of the R-600a refrigerator with MWCNT-FIRC (S2) were lower than those of the refrigerator without MWCNT-FIRC (S1) by 3.39%, 3.61%, and 2.92%, respectively. The results of the 24-h on-load cycling test showed that S2 had a lower electricity consumption, higher slope of pull-down (SPD), higher compression ratio (CR), higher COP, lower duty ratio (DR), and higher energy factor (EF), changing upon those of S1 by −7.05%, 5.66%, 3.24%, 5.92%, −5.63, and 7.89%, respectively. A MWCNT-FIRC on the condenser of an R-600a refrigerator can enhance refrigeration performance and reduce electricity consumption, resulting in energy saving and carbon reduction.

  20. Characterization and temperature controlling property of TiAlN coatings deposited by reactive magnetron co-sputtering

    International Nuclear Information System (INIS)

    Chen, J.T.; Wang, J.; Zhang, F.; Zhang, G.A.; Fan, X.Y.; Wu, Z.G.; Yan, P.X.

    2009-01-01

    Titanium aluminum nitride (TiAlN) ternary coating is a potential material which is expected to be applied on satellite for thermal controlling. In order to investigate thermal controlling property, TiAlN coatings were deposited on Si wafers with different N 2 and Ar flux ratio by reactive magnetron co-sputtering. The structure, morphology, chemical composition and optical reflectance are investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), atom force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and spectrophotometer, respectively. The orientation of the coatings depends on the N 2 /Ar flux ratio. The coatings deposited with N 2 /Ar ratio of 10, 30 and 60% show the cubic-TiN [2 2 0] preferred orientation and the coating deposited with N 2 /Ar ratio of 100% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of the coatings becomes more compact and smoother with the N 2 /Ar ratios increase. XPS spectrum indicates that the oxides (TiO 2 and Al 2 O 3 ), oxynitride (TiN x O y ) and nitrides (TiN and AlN x ) appear at the surface of the coatings. Ignoring internal power, the optimum equilibrium temperature of TiAlN coatings is 18 deg. C and the equilibrium temperature after heat-treated has slight change, which provides the prospective application on thermal controlling

  1. Microbiological quality control of single-walled carbon-nanotubes-coated surfaces experimentally contaminated

    International Nuclear Information System (INIS)

    Natalizi, T.; Frioni, A.; Passeri, D.; Pantanella, F.

    2013-01-01

    The emergence of new nanotechnologies involves the spreading of nanoparticles in various fields of human life. Nanoparticles in general and, more specifically, carbon nanotubes have been adopted for many practical approaches i.e.: coatings for medical devices, food process industry and drug delivery. Humans will be increasingly exposed to nanoparticles but the susceptibility of nanostructured materials to microbial colonization in process of manufacturing and storage has not been thoroughly considered. Therefore, the microbiological quality control of nanoparticles plays a pivotal role. Different analytical methods have been attempted for detecting bacterial population contaminating a surface, but no one can be considered fully appropriate. Here, BioTimer Assay (BTA) and conventional sonication followed by colony forming units method (S-CFU) were applied for microbiological quality control of single-walled carbon nanotubes (SWCNTs)-coated surfaces experimentally contaminated with Streptococcus mutans and Pseudomonas aeruginosa. Our results demonstrated that S-CFU is unreliable to actually determine the number of bacteria, contaminating abiotic surfaces, as it does not detach all adherent bacteria and kills part of the bacterial population. Instead, BTA is a reliable method to enumerate bacteria colonizing SWCNTs-coated surfaces and can be considered a useful tool for microbiological quality control of nanomaterials for human use.

  2. Cell viability and MRI performance of highly efficient polyol-coated magnetic nanoparticles

    International Nuclear Information System (INIS)

    Arteaga-Cardona, Fernando; Gutiérrez-García, Eric; Hidalgo-Tobón, Silvia; López-Vasquez, Ciro; Brito-Barrera, Yazmín A.; Flores-Tochihuitl, Julia; Angulo-Molina, Aracely; Reyes-Leyva, Julio R.; González-Rodríguez, Roberto; Coffer, Jeffery L.; Pal, Umapada

    2016-01-01

    This work aimed at determining conditions that would allow us to control the size of the NPs and create a system with characteristics apt for biomedical applications. We describe a comprehensive study on the synthesis and physical characterization of two highly sensitive sets of triethylene glycol (TREG) and polyethylene glycol (PEG)-coated superparamagnetic iron oxide nanoparticles (SPIONs) to be evaluated for use as magnetic resonance (MR) contrast agents. The ferrofluids demonstrated excellent colloidal stability in deionized water at pH 7.0 as indicated by dynamic light scattering (DLS) data. The magnetic relaxivities, r_2, were measured on a 1.5 T clinical MRI instrument. Values in the range from 205 to 257 mM"−"1 s"−"1 were obtained, varying proportionally to the SPIONs’ sizes and coating nature. Further in vitro cell viability tests and in vivo biodistribution analyses of the intravenously administered nanoparticles showed that the prepared systems have good biocompatibility and migrate to several organs, mainly the meninges, spleen, and liver. Based on these results, our findings demonstrated the potential utility of these nanosystems as clinical contrast agents for MR imaging.

  3. Cell viability and MRI performance of highly efficient polyol-coated magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga-Cardona, Fernando [Universidad de las Américas de Puebla, Departamento de Ciencias Químico-Biológicas (Mexico); Gutiérrez-García, Eric [Instituto Literario, Universidad Autónoma del Estado de México (Mexico); Hidalgo-Tobón, Silvia, E-mail: shid@xanum.uam.mx [Universidad Autónoma Metropolitana, Departamento de Física (Mexico); López-Vasquez, Ciro; Brito-Barrera, Yazmín A. [Universidad de las Américas de Puebla, Departamento de Ciencias Químico-Biológicas (Mexico); Flores-Tochihuitl, Julia [Benemérita Universidad Autónoma de Puebla, Facultad de Estomatología (Mexico); Angulo-Molina, Aracely [Universidad de Sonora, Departamento de Ciencias Químico-Biológicas (Mexico); Reyes-Leyva, Julio R. [Instituto Mexicano del Seguro Social, Centro de Investigación Biomédica de Oriente (CIBIOR) (Mexico); González-Rodríguez, Roberto; Coffer, Jeffery L. [Texas Christian University, Department of Chemistry (United States); Pal, Umapada [Benemérita Universidad Autónoma de Puebla, Apdo, Instituto de Física (Mexico); and others

    2016-11-15

    This work aimed at determining conditions that would allow us to control the size of the NPs and create a system with characteristics apt for biomedical applications. We describe a comprehensive study on the synthesis and physical characterization of two highly sensitive sets of triethylene glycol (TREG) and polyethylene glycol (PEG)-coated superparamagnetic iron oxide nanoparticles (SPIONs) to be evaluated for use as magnetic resonance (MR) contrast agents. The ferrofluids demonstrated excellent colloidal stability in deionized water at pH 7.0 as indicated by dynamic light scattering (DLS) data. The magnetic relaxivities, r{sub 2}, were measured on a 1.5 T clinical MRI instrument. Values in the range from 205 to 257 mM{sup −1} s{sup −1} were obtained, varying proportionally to the SPIONs’ sizes and coating nature. Further in vitro cell viability tests and in vivo biodistribution analyses of the intravenously administered nanoparticles showed that the prepared systems have good biocompatibility and migrate to several organs, mainly the meninges, spleen, and liver. Based on these results, our findings demonstrated the potential utility of these nanosystems as clinical contrast agents for MR imaging.

  4. Near-infrared spectroscopy monitoring and control of the fluidized bed granulation and coating processes-A review.

    Science.gov (United States)

    Liu, Ronghua; Li, Lian; Yin, Wenping; Xu, Dongbo; Zang, Hengchang

    2017-09-15

    The fluidized bed granulation and pellets coating technologies are widely used in pharmaceutical industry, because the particles made in a fluidized bed have good flowability, compressibility, and the coating thickness of pellets are homogeneous. With the popularization of process analytical technology (PAT), real-time analysis for critical quality attributes (CQA) was getting more attention. Near-infrared (NIR) spectroscopy, as a PAT tool, could realize the real-time monitoring and control during the granulating and coating processes, which could optimize the manufacturing processes. This article reviewed the application of NIR spectroscopy in CQA (moisture content, particle size and tablet/pellet thickness) monitoring during fluidized bed granulation and coating processes. Through this review, we would like to provide references for realizing automated control and intelligent production in fluidized bed granulation and pellets coating of pharmaceutical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Ultra-thin solution-based coating of molybdenum oxide on multiwall carbon nanotubes for high-performance supercapacitor electrodes

    KAUST Repository

    Shakir, Imran

    2014-02-01

    Uniform and conformal coating of ultrathin molybdenum oxide (MoO 3) thin film onto conducting MWCNTs was successfully synthesized through a facile, nontoxic and generally applicable precipitation method, followed by a simple heat treatment. The ultrathin MoO3 coating enables a fast and reversible redox reaction which improves the specific capacitance by utilizing the maximum number of active sites for the redox reaction, while the high porosity of the MWCNTs facilitates ion migration in the electrolyte and shorten the ion diffusion path. The ultrathin MoO3 coated MWCNTs electrodes show a very high specific capacitance of 1145 Fg -1 in 2 M Na2SO4 aqueous solution when 5 nm thick MoO3 was considered alone despite the low weight percentage of the MoO3 (16wt%). Furthermore, the ultrathin MoO3 coated MWCNTs supercapacitor electrodes exhibited excellent cycling performance of > 97% capacitance retention over 1000 cycles. © 2013 Elsevier Ltd.

  6. Electrochemical performance of carbon-coated lithium manganese silicate for asymmetric hybrid supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Karthikeyan, K.; Lee, S.B.; Jang, I.C.; Lim, H.H.; Lee, Y.S. [Faculty of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757 (Korea); Aravindan, V. [The Research Institute for Catalysis, Chonnam National University, Gwangju 500-757 (Korea); Park, G.J.; Yoshio, M. [Department of Applied Chemistry, Saga University, Saga 840-8502 (Japan)

    2010-06-01

    Nanoscale carbon-coated Li{sub 2}MnSiO{sub 4} powder is prepared using a conventional solid-state method and can be used as the negative electrode in a Li{sub 2}MnSiO{sub 4}/activated carbon (AC) hybrid supercapacitor. Carbon-coated Li{sub 2}MnSiO{sub 4} material presents a well-developed orthorhombic crystal structure with a Pmn2{sub 1} space group, although there is a small impurity of MnO. The maximum specific capacitance of the Li{sub 2}MnSiO{sub 4}/AC hybrid supercapacitor is 43.2 F g{sup -1} at 1 mA cm{sup -2} current density. The cell delivers a specific energy as high as 54 Wh kg{sup -1} at a specific power of 150 W kg{sup -1} and also exhibits an excellent cycle performance with more than 99% columbic efficiency and the maintenance of 85% of its initial capacitance after 1000 cycles. (author)

  7. Pyrolytic carbon-coated stainless steel felt as a high-performance anode for bioelectrochemical systems.

    Science.gov (United States)

    Guo, Kun; Hidalgo, Diana; Tommasi, Tonia; Rabaey, Korneel

    2016-07-01

    Scale up of bioelectrochemical systems (BESs) requires highly conductive, biocompatible and stable electrodes. Here we present pyrolytic carbon-coated stainless steel felt (C-SS felt) as a high-performance and scalable anode. The electrode is created by generating a carbon layer on stainless steel felt (SS felt) via a multi-step deposition process involving α-d-glucose impregnation, caramelization, and pyrolysis. Physicochemical characterizations of the surface elucidate that a thin (20±5μm) and homogenous layer of polycrystalline graphitic carbon was obtained on SS felt surface after modification. The carbon coating significantly increases the biocompatibility, enabling robust electroactive biofilm formation. The C-SS felt electrodes reach current densities (jmax) of 3.65±0.14mA/cm(2) within 7days of operation, which is 11 times higher than plain SS felt electrodes (0.30±0.04mA/cm(2)). The excellent biocompatibility, high specific surface area, high conductivity, good mechanical strength, and low cost make C-SS felt a promising electrode for BESs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Corrosion Protection Performance of Polyester-Melamine Coating with Natural Wood Fiber Using EIS Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, PyongHwa; Shon, MinYoung [Pukyong National University, Busan (Korea, Republic of); Jo, DuHwan [POSCO, Gwangyang (Korea, Republic of)

    2016-04-15

    In the present study, polyester-melamine coating systems with natural wood fiber (NWF) were prepared and the effects of NWF on the corrosion protectiveness of the polyester-melamine coating were examined using EIS analysis. From the results, higher average surface roughness was observed with increase of NWF content. Water diffusivity and water uptake into the polyester-melamine coatings with NWF were much higher than that into the pure polyester-melamine coating. The decrease in the impedance modulus |Z| was associated with the localized corrosion on carbon steel, confirming that corrosion protection of the polyester-melamine coatings with NWF well agrees with its water transport behavior.

  9. The effect of solvents and hydrophilic additive on stable coating and controllable sirolimus release system for drug-eluting stent.

    Science.gov (United States)

    Kim, Seong Min; Park, Sung-Bin; Bedair, Tarek M; Kim, Man-Ho; Park, Bang Ju; Joung, Yoon Ki; Han, Dong Keun

    2017-09-01

    Various drug-eluting stents (DESs) have been developed to prevent restenosis after stent implantation. However, DES still needs to improve the drug-in-polymer coating stability and control of drug release for effective clinical treatment. In this study, the cobalt-chromium (CoCr) alloy surface was coated with biodegradable poly(D,L-lactide) (PDLLA) and sirolimus (SRL) mixed with hydrophilic Pluronic F127 additive by using ultrasonic spray coating system in order to achieve a stable coating surface and control SRL release. The degradation of PDLLA/SRL coating was studied under physiological solution. It was found that adding F127 reduced the degradation of PDLLA and improved the coating stability during 60days. The effects of organic solvent such as chloroform and tetrahydrofuran (THF) on the coating uniformity were also examined. It was revealed that THF produced a very smooth and uniform coating compared to chloroform. The patterns of in vitro drug release according to the type of organic solvent and hydrophilic additive proposed the possibility of controllable drug release design in DES. It was found that using F127 the drug release was sustained regardless of the organic solvent used. In addition, THF was able to get faster and controlled release profile when compared to chloroform. The structure of SRL molecules in different organic solvents was investigated using ultra-small angle neutron scattering. Furthermore, the structure of SRL is concentration-dependent in chloroform with tight nature under high concentration, but concentration-independent in THF. These results strongly demonstrated that coating stability and drug release patterns can be changed by physicochemical properties of various parameters such as organic solvents, additive, and coating strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Effect of Graphene Coating on the Heat Transfer Performance of a Composite Anti-/Deicing Component

    Directory of Open Access Journals (Sweden)

    Long Chen

    2017-09-01

    Full Text Available The thermal conductivity of a graphene coating for anti-/deicing is rarely studied. This paper presents an improved anti-/deicing efficiency method for composite material anti-/deicing by using the heat-transfer characteristic of a graphene coating. An anti-/deicing experiment was conducted using the centrifugal force generated by a helicopter rotor. Results showed that the graphene coating can accelerate the internal heat transfer of the composite material, thereby improving the anti-icing and deicing efficiency of the helicopter rotor. The spraying process parameters, such as coating thickness and spraying pressure, were also studied. Results showed that reducing coating thickness and increasing spraying pressure are beneficial in preparing a graphene coating with high thermal conductivity. This study provides an experimental reference for the application of a graphene coating in anti-/deicing.

  11. Fire performance, microstructure and thermal degradation of an epoxy based nano intumescent fire retardant coating for structural applications

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Hammad, E-mail: engr.hammad.aziz03@gmail.com; Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Yusoff, P. S. M. Megat; Zia-ul-Mustafa, M. [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Tronoh 31750, Perak (Malaysia)

    2015-07-22

    Intumescent fire retardant coating (IFRC) is a passive fire protection system which swells upon heating to form expanded multi-cellular char layer that protects the substrate from fire. In this research work, IFRC’s were developed using different flame retardants such as ammonium polyphosphate, expandable graphite, melamine and boric acid. These flame retardants were bound together with the help of epoxy binder and cured together using curing agent. IFRC was then reinforced with nano magnesium oxide and nano alumina as inorganic fillers to study their effect towards fire performance, microstructure and thermal degradation. Small scale fire test was conducted to investigate the thermal insulation of coating whereas fire performance was calculated using thermal margin value. Field emission scanning electron microscopy was used to examine the microstructure of char obtained after fire test. Thermogravimetric analysis was conducted to investigate the residual weight of coating. Results showed that the performance of the coating was enhanced by reinforcement with nano size fillers as compared to non-filler based coating. Comparing both nano size magnesium oxide and nano size alumina; nano size alumina gave better fire performance with improved microstructure of char and high residual weight.

  12. Conjugate heat transfer investigation on the cooling performance of air cooled turbine blade with thermal barrier coating

    Science.gov (United States)

    Ji, Yongbin; Ma, Chao; Ge, Bing; Zang, Shusheng

    2016-08-01

    A hot wind tunnel of annular cascade test rig is established for measuring temperature distribution on a real gas turbine blade surface with infrared camera. Besides, conjugate heat transfer numerical simulation is performed to obtain cooling efficiency distribution on both blade substrate surface and coating surface for comparison. The effect of thermal barrier coating on the overall cooling performance for blades is compared under varied mass flow rate of coolant, and spatial difference is also discussed. Results indicate that the cooling efficiency in the leading edge and trailing edge areas of the blade is the lowest. The cooling performance is not only influenced by the internal cooling structures layout inside the blade but also by the flow condition of the mainstream in the external cascade path. Thermal barrier effects of the coating vary at different regions of the blade surface, where higher internal cooling performance exists, more effective the thermal barrier will be, which means the thermal protection effect of coatings is remarkable in these regions. At the designed mass flow ratio condition, the cooling efficiency on the pressure side varies by 0.13 for the coating surface and substrate surface, while this value is 0.09 on the suction side.

  13. Microstructural control of TiC/a-C nanocomposite coatings with pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Pei, Y.T.; Chen, C.Q.; Shaha, K.P.; De Hosson, J.Th.M.; Bradley, J.W.; Voronin, S.A.; Cada, M.

    2008-01-01

    In this paper, we report some striking results on the microstructural control of TiC/a-C nanocomposite coatings with pulsed direct current (DC) magnetron sputtering. The interface morphology and microstructure evolution as a function of pulse frequency and duty cycle were scrutinized using atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy techniques. It is shown that, with increasing pulse frequency, the nanocomposite coatings exhibit evolutions in morphology of the growing interface from rough to smooth and in the microstructure from strongly columnar to fully columnar-free. In addition, the smoothly growing interface favors the formation of a tailor-made multilayered nanocomposite structure. The fundamental mechanisms are analyzed with the assistance of plasma diagnostic experiments. Ion mass/energy spectrometry measurements reveal that, depending on the frequency and duty cycle of DC pulses, pulsing of the magnetrons can control the flux and energy distribution of Ar + ions over a very broad range for concurrent impingement on the growing interface of deposited coatings, in comparison with DC sputtering. The significantly enhanced energy flux density is thought to be responsible for the 'adatom transfer' in interface smoothening and thus the restraint of columnar growth

  14. Tuning dipolar magnetic interactions by controlling individual silica coating of iron oxide nanoparticles

    Science.gov (United States)

    Rivas Rojas, P. C.; Tancredi, P.; Moscoso Londoño, O.; Knobel, M.; Socolovsky, L. M.

    2018-04-01

    Single and fixed size core, core-shell nanoparticles of iron oxides coated with a silica layer of tunable thickness were prepared by chemical routes, aiming to generate a frame of study of magnetic nanoparticles with controlled dipolar interactions. The batch of iron oxides nanoparticles of 4.5 nm radii, were employed as cores for all the coated samples. The latter was obtained via thermal decomposition of organic precursors, resulting on nanoparticles covered with an organic layer that was subsequently used to promote the ligand exchange in the inverse microemulsion process, employed to coat each nanoparticle with silica. The amount of precursor and times of reaction was varied to obtain different silica shell thicknesses, ranging from 0.5 nm to 19 nm. The formation of the desired structures was corroborated by TEM and SAXS measurements, the core single-phase spinel structure was confirmed by XRD, and superparamagnetic features with gradual change related to dipolar interaction effects were obtained by the study of the applied field and temperature dependence of the magnetization. To illustrate that dipolar interactions are consistently controlled, the main magnetic properties are presented and analyzed as a function of center to center minimum distance between the magnetic cores.

  15. Nucleation and Growth of Porous MnO2 Coatings Prepared on Nickel Foam and Evaluation of Their Electrochemical Performance

    Directory of Open Access Journals (Sweden)

    Wenxin Huang

    2018-05-01

    Full Text Available Porous MnO2 was uniformly electrodeposited on nickel foam in MnSO4 solution, which was applied as the electrode of supercapacitors. The nucleation/growth mechanisms of porous MnO2 were investigated firstly. Then two kinds of electrochemical measuring technologies, corresponding to the cycle voltammetry (CV and galvanostatic charge-discharge, were adopted to assess the electrochemical performance of MnO2 electrodes. The results demonstrated that the deposition of MnO2 on nickel foam included four stages. Prior to the deposition, an extremely short incubation period of about 2 s was observed (the first stage. Then the exposed nickel foam was instantly covered by a large number of MnO2 crystal nuclei and crystal nuclei connected with each other in a very short time of about 3 s (the second stage. Nucleation predominated in the second stage. The sharply rise of current was caused by the increase in substrate surface area which due to nucleation of MnO2. Grain boundaries grew preferentially due to their high energy, accompanied with a honeycomb-like structure with the higher surface area was formed. However, accompanied with the electrochemical reactions gradually diffusion-controlled, the current presented the decline trend with increasing the time (the third stage. When the electrochemical reactions were completely diffusion-controlled, the porous MnO2 coating with an approximately constant surface area was formed (the fourth stage. MnO2 coatings deposited for different time (30, 60, 120, 300 s exhibited a similar specific capacitance (CV: about 224 F/g; galvanostatic charge-discharge: about 264 F/g. Comparatively speaking, the value of MnO2 deposited for 600 s was highest (CV: 270 F/g; galvanostatic charge-discharge: 400 F/g.

  16. Performance study of desiccant coated heat exchanger air conditioning system in winter

    International Nuclear Information System (INIS)

    Ge, T.S.; Dai, Y.J.; Wang, R.Z.

    2016-01-01

    Highlights: • Performance of desiccant coated heat exchanger AC system is predicted. • Effects of main operation parameters and climatic conditions are discussed. • Regeneration temperature of 30 °C is recommended under simulation condition. • Higher ambient humidity ratio results in increased humidity ratio of supply air. • Temperature of ambient air has neglectable effect on supply air. - Abstract: Conventional air source heat pump system faces several challenges when adopted in winter season. Solid desiccant air conditioning system can provide humidification and heating power simultaneously and can be driven by low grade thermal energy; it provides a good alternative for air source heat pump systems. However, conventional solid desiccant air conditioning system adopts desiccant wheel with high cost as core component, which hinders the development of such system. Recently, desiccant coated heat exchanger (DCHE) with low initial cost and high efficiency was developed and this paper aims to investigate performance of DCHE air conditioning system adopted in Shanghai winter season. Performance of the system is predicted by a developed mathematical model where supply air states, mass of humidification and coefficient of performance (COP) are adopted as performance indices to evaluate the feasibility and energy utilization ratio of the system. Effects of regeneration water temperature on system performance are analyzed. It is found that under the simulation condition, relatively low regeneration temperature (such as 20 °C) cannot meet the designed standard and relatively high regeneration temperature (such as 40 °C) provides too much extra heating power, thus moderate regeneration temperature around 30 °C is recommended. Meanwhile, switch time is a crucial operation parameter for the system to obtain satisfied supply air, switch time from 40 s to 80 s and from 70 s to 240 s are recommended for transient and average supply air states, respectively. Both

  17. Performance estimates for personnel access control systems

    International Nuclear Information System (INIS)

    Bradley, R.G.

    1980-10-01

    Current performance estimates for personnel access control systems use estimates of Type I and Type II verification errors. A system performance equation which addresses normal operation, the insider, and outside adversary attack is developed. Examination of this equation reveals the inadequacy of classical Type I and II error evaluations which require detailed knowledge of the adversary threat scenario for each specific installation. Consequently, new performance measures which are consistent with the performance equation and independent of the threat are developed as an aid in selecting personnel access control systems

  18. Performance of coils wound from long lengths of surface-coated, reacted, BSCCO-2212 conductor

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M.S.; Hazelton, D.W.; Gardner, M.T. [Intermagnetics General Corp., Latham, NY (United States)] [and others

    1996-10-01

    React-before-wind surface-coated BSCCO-2212 is being established as a relatively low cost HTS conductor for practical applications. Quality tape is presently being manufactured in 450-500m lengths at a cost estimated to be 1/3-1/5 of the industry costs of BSCCO-2223 powder-in-tube tape. Robust, mechanically sound coils for applications ranging from NMR insert magnets to transformer windings are being made from this BSCCO-2212 tape. The coils have performed consistently through test and thermal cycling without degradation and as projected from short sample measurements. A hybrid approach, which uses mainly BSCCO- 2212 augmented by BSCCO-2223 conductor in the high radial field end regions, is expected to halve magnet system costs.

  19. Performance of a Boron-Coated-Straw-Based HLNCC for International Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Angela T. [ORNL; Croft, Stephen [ORNL; McElroy, Robert Dennis [ORNL; Sun, Liang [Proportional Technologies Inc.; Hayward, Jason P. [ORNL

    2017-08-01

    3He gas has been used in various scientific and security applications for decades, but it is now in short supply. Alternatives to 3He detectors are currently being integrated and tested in neutron coincidence counter designs, of a type which are widely used in nuclear safeguards for nuclear materials assay. A boron-coated-straw-based design, similar to the High-Level Neutron Coincidence Counter-II, was built by Proportional Technologies Inc., and has been tested by the Oak Ridge National Laboratory (ORNL) at both the JRC in Ispra and ORNL. Characterization measurements, along with nondestructive assays of various plutonium samples, have been conducted to determine the performance of this coincidence counter replacement in comparison with other similar counters. This paper presents results of these measurements.

  20. Performance Testing of Suspension Plasma Sprayed Thermal Barrier Coatings Produced with Varied Suspension Parameters

    Directory of Open Access Journals (Sweden)

    Nicholas Curry

    2015-07-01

    Full Text Available Suspension plasma spraying has become an emerging technology for the production of thermal barrier coatings for the gas turbine industry. Presently, though commercial systems for coating production are available, coatings remain in the development stage. Suitable suspension parameters for coating production remain an outstanding question and the influence of suspension properties on the final coatings is not well known. For this study, a number of suspensions were produced with varied solid loadings, powder size distributions and solvents. Suspensions were sprayed onto superalloy substrates coated with high velocity air fuel (HVAF -sprayed bond coats. Plasma spray parameters were selected to generate columnar structures based on previous experiments and were maintained at constant to discover the influence of the suspension behavior on coating microstructures. Testing of the produced thermal barrier coating (TBC systems has included thermal cyclic fatigue testing and thermal conductivity analysis. Pore size distribution has been characterized by mercury infiltration porosimetry. Results show a strong influence of suspension viscosity and surface tension on the microstructure of the produced coatings.

  1. Plasma electrolytic oxidation of titanium in a phosphate/silicate electrolyte and tribological performance of the coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aliasghari, S.; Skeldon, P., E-mail: p.skeldon@manchester.ac.uk; Thompson, G.E.

    2014-10-15

    Highlights: • Plasma electrolytic oxidation performed of titanium in silicate/phosphate electrolyte. • Range of duty cycle, current density, positive-to-negative current ratio studied. • Coatings contain anatase, rutile, Ti{sub 3}O{sub 5}, and amorphous silica. • Ptfe incorporated into coatings by addition of ptfe emulsion to the electrolyte. • Fiction reduced but wear life relatively short due to porosity of coatings. - Abstract: Plasma electrolytic oxidation of titanium has been investigated using a phosphate/silicate electrolyte with a square waveform and a frequency of 50 Hz. A range of constant rms current densities, duty cycles and negative-to-positive current ratios was employed. The resultant coatings were examined by analytical scanning and transmission electron microscopies and X-ray diffraction. The coatings, which were limited in thickness to ∼40 to 50 μm, contained anatase, rutile, Ti{sub 2}O{sub 5} and silicon-rich, amorphous material. The tribological behaviour was investigated using a ball-on-disc test, revealing a coefficient of friction against steel of ∼0.8, which reduced to ∼0.4 by incorporation of ptfe particles from the electrolyte. However, due to the composition and morphology of the coatings, their wear life was relatively short.

  2. Plasma electrolytic oxidation of titanium in a phosphate/silicate electrolyte and tribological performance of the coatings

    International Nuclear Information System (INIS)

    Aliasghari, S.; Skeldon, P.; Thompson, G.E.

    2014-01-01

    Highlights: • Plasma electrolytic oxidation performed of titanium in silicate/phosphate electrolyte. • Range of duty cycle, current density, positive-to-negative current ratio studied. • Coatings contain anatase, rutile, Ti 3 O 5 , and amorphous silica. • Ptfe incorporated into coatings by addition of ptfe emulsion to the electrolyte. • Fiction reduced but wear life relatively short due to porosity of coatings. - Abstract: Plasma electrolytic oxidation of titanium has been investigated using a phosphate/silicate electrolyte with a square waveform and a frequency of 50 Hz. A range of constant rms current densities, duty cycles and negative-to-positive current ratios was employed. The resultant coatings were examined by analytical scanning and transmission electron microscopies and X-ray diffraction. The coatings, which were limited in thickness to ∼40 to 50 μm, contained anatase, rutile, Ti 2 O 5 and silicon-rich, amorphous material. The tribological behaviour was investigated using a ball-on-disc test, revealing a coefficient of friction against steel of ∼0.8, which reduced to ∼0.4 by incorporation of ptfe particles from the electrolyte. However, due to the composition and morphology of the coatings, their wear life was relatively short

  3. Effect of CeO2-coating on the electrochemical performances of LiFePO4/C cathode material

    International Nuclear Information System (INIS)

    Yao Jingwen; Wu Feng; Qiu Xinping; Li Ning; Su Yuefeng

    2011-01-01

    Highlights: → The first study the effect of CeO 2 coating on LiFePO 4 /C at low temperature. → Coated cathode shows improved capacities at high rates and low temperature. → CeO 2 -coating decreases electrode polarization and increases charge-transfer reaction activity. - Abstract: The effect of CeO 2 coating on LiFePO 4 /C cathode material has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, TEM and their electrochemical performances both at room temperature and low temperature are evaluated by CV, EIS and galvanostatic charge/discharge tests. It is found that, nano-CeO 2 particles distribute on the surface of LiFePO 4 without destroying the crystal structure of the bulk material. The CeO 2 -coated LiFePO 4 /C cathode material shows improved lithium insertion/extraction capacity and electrode kinetics, especially at high rates and low temperature. At -20 deg. C, the CeO 2 -coated material delivers discharge capacity of 99.7 mAh/g at 0.1C rate and the capacity retention of 98.6% is obtained after 30 cycles at various charge/discharge rates. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.

  4. Microstructure and Tribological Performance of TiB2-NiCr Composite Coating Deposited by APS

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2017-12-01

    Full Text Available Nickel chromium (NiCr powders with different titanium diboride (TiB2 additions (20, 40 and 60 wt % were prepared with a mechanical alloying method and then sprayed using an air plasma spraying technology. The microstructure and phase composite of the powders and the cross-sections of deposited coatings were analyzed with a scanning electronic microscope and X-ray diffraction. The tribological performance of the coatings was studied using a pin-on-disk tribometer at room temperature. The weight loss of the as-sprayed coating was measured by using a high accuracy weighing balance. Cr3C2-25NiCr coating was produced and tested for comparison. The morphologies of the worn surface were then investigated. Parts of debris with some scratches were found, presenting typical signs of abrasive wear and showing slight adhesive wear on the surface. The 20 wt % additive TiB2 coating demonstrated the highest microhardness and the lowest coefficient of friction. The wear resistance of the metal-ceramic composites coatings was enhanced with the addition of TiB2.

  5. Performance analysis of LMFBR control rods

    International Nuclear Information System (INIS)

    Pitner, A.L.; Birney, K.R.

    1975-01-01

    Control rods in the FFTF and LMFBR's will consist of pin bundles of stainless steel-clad boron carbide pellets. In the FFTF reference design, sixty-one pins of 0.474-inch diameter each containing a 36-inch stack of 0.362-inch diameter boron carbide pellets comprise a control rod. Reactivity control is provided by the 10 B (n,α) 7 Li reaction in the boron carbide. This reaction is accompanied by an energy release of 2.8 MeV, and heating from this reaction typically approaches 100 watts/cm 3 for natural boron carbide pellets in an LMFBR flux. Performance analysis of LMFBR control rods must include an assessment of the thermal performance of control pins. In addition, irradiation performance with regard to helium release, pellet swelling, and reactivity worth depletion as a function of service time must be evaluated

  6. Internal Control Good Cooperative Governance And Performance

    Directory of Open Access Journals (Sweden)

    Andry Arifian Rachman

    2017-11-01

    Full Text Available This study aims to examine the influence of internal control and good cooperative governance partially and simultaneously to the performance of cooperatives in West Java Province. The research method used in this research is descriptive and verification. The sample in this research is 22 boards as manager of cooperative in West Java Province. The data used in the research is the primary data through questionnaire collection. Validity and reliability testing is performed before hypothesis testing. This research uses multiple regression analysis technique. Based on hypothesis testing obtained 1 internal control has no significant effect on performance 2 good cooperative governance has a significant effect on performance and 3 internal control and good cooperative governance have a significant effect on performance.

  7. Effects of supplemental coated or crystalline methionine in low-fishmeal diet on the growth performance and body composition of juvenile cobia Rachycentron canadum (Linnaeus)

    Science.gov (United States)

    Chi, Shuyan; Tan, Beiping; Dong, Xiaohui; Yang, Qihui; Liu, Hongyu

    2014-11-01

    We evaluated the effects of supplemental coated and crystalline methionine (Met) on the growth performance and feed utilization of juvenile cobia ( Rachycentron canadum Linnaeus) in a 60-d feeding trial. Fish groups were fed one of six isonitrogenous and isolipidic diets: 1) fishmeal control; 2) un-supplemented experimental (low-fish-meal diet deficient in Met); or 3) one of four Met diets supplemented with crystalline L-Met, cellulose-acetate-phthalate coated L-Met, acrylic-resin coated L-Met, or tripalmitin-polyvinyl alcohol coated L-Met. The test diets were fed to triplicate groups of cobia (initial body weight 5.40±0.07 g) twice a day. The weight gain and specific growth rate of the fish fed the RES diet were highest among the Met-supplemented groups and were 23.64% and 7.99%, respectively, higher than those of the fish fed with the un-supplemented experimental diet ( Pcobia.

  8. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS): A rapid test for enteric coating thickness and integrity of controlled release pellet formulations.

    Science.gov (United States)

    Alfarsi, Anas; Dillon, Amy; McSweeney, Seán; Krüse, Jacob; Griffin, Brendan; Devine, Ken; Sherry, Patricia; Henken, Stephan; Fitzpatrick, Stephen; Fitzpatrick, Dara

    2018-04-12

    There are no rapid dissolution based tests for determining coating thickness, integrity and drug concentration in controlled release pellets either during production or post-production. The manufacture of pellets requires several coating steps depending on the formulation. The sub-coating and enteric coating steps typically take up to six hours each followed by additional drying steps. Post production regulatory dissolution testing also takes up to six hours to determine if the batch can be released for commercial sale. The thickness of the enteric coating is a key factor that determines the release rate of the drug in the gastro-intestinal tract. Also, the amount of drug per unit mass decreases with increasing thickness of the enteric coating. In this study, the coating process is tracked from start to finish on an hourly basis by taking samples of pellets during production and testing those using BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy). BARDS offers a rapid approach to characterising enteric coatings with measurements based on reproducible changes in the compressibility of a solvent due to the evolution of air during dissolution. This is monitored acoustically via associated changes in the frequency of induced acoustic resonances. A steady state acoustic lag time is associated with the disintegration of the enteric coatings in basic solution. This lag time is pH dependent and is indicative of the rate at which the coating layer dissolves. BARDS represents a possible future surrogate test for conventional USP dissolution testing as its data correlates directly with the thickness of the enteric coating, its integrity and also with the drug loading as validated by HPLC. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Carbon-based coating containing ultrafine MoO2 nanoparticles as an integrated anode for high-performance lithium-ion batteries

    Science.gov (United States)

    Li, Quanyi; Yang, Qi; Zhao, Yanhong; Wan, Bin

    2017-10-01

    Copper-supported MoO2-C composite as an integrated anode with excellent battery performance was synthesized by a facile knife coating technique followed by heat treatment in a vacuum. The obtained samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis, nitrogen adsorption and desorption analysis, field emission scanning microscopy (FESEM), and transmission electron microscopy (TEM). The results show the MoO2-C composite coating is comprised of a porous carbon matrix with a pore size of 1-3 nm and ultrafine MoO2 nanoparticles with a size of 5-10 nm encapsulated inside, the coating is tightly attached on the surface of copper foil, and the interface between them is free of cracks. Stable PAN-DMF-H2O system containing ammonium molybdate suitable for knife coating technique and the MoO2-C composite with ultrafine MoO2 nanoparticles encapsulated in the carbon matrix can be prepared through controlling amount of added ammonium molybdate solution. The copper-supported MoO2-C composite coating can be directly utilized as the integrated anode for lithium-ion batteries (LIBs). It delivers a capacity of 814 mA h g-1 at a current density of 100 mA g-1 after 100 cycles without apparent capacity fading. Furthermore, with increase of current densities to 200, 500, 1000, 2000, and 5000 mA g-1, it exhibits average capacities of 809, 697, 568, 383, and 188 mA h g-1. Its outstanding electrochemical performance is attributed to combined merits of integrated anode and structure with ultrafine MoO2 nanoparticles embedded in the porous carbon matrix.

  10. Control of substrate oxidation in MOD cerawwwmic coating on low-activation ferritic steel with reduced-pressure atmosphere

    Science.gov (United States)

    Tanaka, Teruya; Muroga, Takeo

    2014-12-01

    An Er2O3 ceramic coating fabricated using the metal-organic decomposition (MOD) method on a Cr2O3-covered low-activation ferritic steel JLF-1 substrate was examined to improve hydrogen permeation barrier performance of the coating. The Cr2O3 layer was obtained before coating by heat treating the substrate at 700 °C under reduced pressures of baking. Preprocessing to obtain a Cr2O3 layer would provide flexibility in the coating process for blanket components and ducts. Moreover, the Cr2O3 layer suppressed hydrogen permeation through the JLF-1 substrate. While further optimization of the coating fabrication process is required, it would be possible to suppress hydrogen permeation significantly by multilayers of Cr2O3 and MOD oxide ceramic.

  11. Introduction to control system performance measurements

    CERN Document Server

    Garner, K C

    1968-01-01

    Introduction to Control System Performance Measurements presents the methods of dynamic measurements, specifically as they apply to control system and component testing. This book provides an introduction to the concepts of statistical measurement methods.Organized into nine chapters, this book begins with an overview of the applications of automatic control systems that pervade almost every area of activity ranging from servomechanisms to electrical power distribution networks. This text then discusses the common measurement transducer functions. Other chapters consider the basic wave

  12. Performance control of Chinese investment funds

    NARCIS (Netherlands)

    Cao, X.

    2002-01-01

    The performance control of investment funds has long been a discussed focal point by both academics and practitioners because of the ready availability of fund data and the importance of fund performance in attracting investors. Unfortunately, this area was still an almost blank space in the Chinese

  13. Anhydrous polymer-based coating with sustainable controlled release functionality for facile, efficacious impregnation, and delivery of antimicrobial peptides.

    Science.gov (United States)

    Lim, Kaiyang; Saravanan, Rathi; Chong, Kelvin K L; Goh, Sharon H M; Chua, Ray R Y; Tambyah, Paul A; Chang, Matthew W; Kline, Kimberly A; Leong, Susanna S J

    2018-04-17

    Anhydrous polymers are actively explored as alternative materials to overcome limitations of conventional hydrogel-based antibacterial coating. However, the requirement for strong organic solvent in polymerization reactions often necessitates extra protection steps for encapsulation of target biomolecules, lowering encapsulation efficiency, and increasing process complexity. This study reports a novel coating strategy that allows direct solvation and encapsulation of antimicrobial peptides (HHC36) into anhydrous polycaprolactone (PCL) polymer-based dual layer coating. A thin 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) film is layered onto the peptide-impregnated PCL as a diffusion barrier, to modulate and enhance release kinetics. The impregnated peptides are eventually released in a controlled fashion. The use of 2,2,2-trifluoroethanol (TFE), as polymerization and solvation medium, induces the impregnated peptides to adopt highly stable turned conformation, conserving peptide integrity, and functionality during both encapsulation and subsequent release processes. The dual layer coating showed sustained antibacterial functionality, lasting for 14 days. In vivo assessment using an experimental mouse wounding model demonstrated good biocompatibility and significant antimicrobial efficacy of the coating under physiological conditions. The coating was translated onto silicone urinary catheters and showed promising antibacterial efficacy, even outperforming commercial silver-based Dover cather. This anhydrous polymer-based platform holds immense potential as an effective antibacterial coating to prevent clinical device-associated infections. The simplicity of the coating process enhances its industrial viability. © 2018 Wiley Periodicals, Inc.

  14. Electroless Ni–B Coating of Pure Titanium Surface for Enhanced Tribocorrosion Performance in Artificial Saliva and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    F. Mindivan

    2017-05-01

    Full Text Available In the present study, the surface of commercial pure (Grade 2 titanium was coated with electroless Ni–B. The surface morphology, microstructure and phase identification were analysed by X-Ray Diffraction (XRD and Field Emission Gun Scanning Electron Microscope (FEG-SEM equipped with Energy Dispersive X-ray Spectroscopy (EDS. The tribocorrosion performance in a laboratory simulated artificial saliva was investigated using a reciprocating ball-on-plate tribometer coupled to an electrochemical cell. The antibacterial property of the electroless Ni–B film coated on pure titanium was basically investigated. From this study, it may be concluded that this electroless Ni–B coating process cannot only improve the hardness and tribocorrosion performance of the pure titanium, but can also provide antimicrobial activity.

  15. Initiation and Performance of a Coating for Countering Chromium Poisoning in a SOFC-stack

    DEFF Research Database (Denmark)

    Nielsen, Karsten Agersted; Persson, Åsa Helen; Beeaff, Dustin

    2007-01-01

    Minimising transport of chromium from the metallic interconnect (e.g. of Crofer 22APU) to the cathode in a planar solid oxide fuel cell is done by application of a coating between the two parts. The coating is applied by slurry coating, and taken through stack initialisation it transforms...... into a stable and densely grown barrier layer, which minimises both the evaporation of chromium from the interconnect surface and the electrical contact resistance between the interconnect and the cathode. Between comparable stack element tests with and without coatings at 750 degrees C, the degradation rate...

  16. Simulation and parametric study of a film-coated controlled-release pharmaceutical.

    Science.gov (United States)

    Borgquist, Per; Zackrisson, Gunnar; Nilsson, Bernt; Axelsson, Anders

    2002-04-23

    Pharmaceutical formulations can be designed as Multiple Unit Systems, such as Roxiam CR, studied in this work. The dose is administrated as a capsule, which contains about 100 individual pellets, which in turn contain the active drug remoxipride. Experimental data for a large number of single pellets can be obtained by studying the release using microtitre plates. This makes it possible to study the release of the individual subunits making up the total dose. A mathematical model for simulating the release of remoxipride from single film-coated pellets is presented including internal and external mass transfer hindrance apart from the most important film resistance. The model can successfully simulate the release of remoxipride from single film-coated pellets if the lag phase of the experimental data is ignored. This was shown to have a minor influence on the release rate. The use of the present model is demonstrated by a parametric study showing that the release process is film-controlled, i.e. is limited by the mass transport through the polymer coating. The model was used to fit the film thickness and the drug loading to the experimental release data. The variation in the fitted values was similar to that obtained in the experiments.

  17. Enhancing the electrochemical performance of commercial TiO2 by eliminating sulfate radicals and coating carbon

    International Nuclear Information System (INIS)

    Wang, Li-Ying; Wu, Yan; Han, Jian-Ping; Zhang, Bo; Bai, Xue; Qi, Yong-Xin; Lun, Ning; Cao, Yu-Mei; Bai, Yu-Jun

    2017-01-01

    Highlights: •Commercial TiO 2 (c-TiO 2 ) exhibits poor electrochemical performance. •The performance of c-TiO 2 is improved by coating carbon at temperatures above 750 °C. •The removal of SO 4 2− and formation of carbon coating are responsible for the enhanced performance. -- Abstract: Despite the low price of commercial TiO 2 (c-TiO 2 ), the poor electrochemical performance restricts its practical application in Li-ion batteries, so clarifying the reasons and taking appropriate measures to improve the performance are of great significance. Herein, c-TiO 2 was coated with carbon at 600 and 750 °C using glucose as the carbon source. The product obtained at 750 °C exhibits markedly enhanced reversible capacities and outstanding rate performance compared to that obtained at 600 °C. In terms of the comparative experiments and detailed characterizations by several techniques, the SO 4 2− remained in the c-TiO 2 is the dominant impurity affecting the electrochemical performance mostly. The thorough decomposition of SO 4 2− at 750 °C and the formation of carbon coating give rise to the enhanced electronic and ionic conductivities of the c-TiO 2 , and thus are responsible for the significant improvement in the electrochemical performance. The easy fabrication and the low cost of the raw materials enable the carbon-coated c-TiO 2 to industrially apply in the LIBs.

  18. The COMPASS Tokamak Plasma Control Software Performance

    Science.gov (United States)

    Valcarcel, Daniel F.; Neto, André; Carvalho, Ivo S.; Carvalho, Bernardo B.; Fernandes, Horácio; Sousa, Jorge; Janky, Filip; Havlicek, Josef; Beno, Radek; Horacek, Jan; Hron, Martin; Panek, Radomir

    2011-08-01

    The COMPASS tokamak has began operation at the IPP Prague in December 2008. A new control system has been built using an ATCA-based real-time system developed at IST Lisbon. The control software is implemented on top of the MARTe real-time framework attaining control cycles as short as 50 μs, with a jitter of less than 1 μs. The controlled parameters, important for the plasma performance, are the plasma current, position of the plasma current center, boundary shape and horizontal and vertical velocities. These are divided in two control cycles: slow at 500 μs and fast at 50 μs. The project has two phases. First, the software implements a digital controller, similar to the analog one used during the COMPASS-D operation in Culham. In the slow cycle, the plasma current and position are measured and controlled with PID and feedforward controllers, respectively, the shaping magnetic field is preprogrammed. The vertical instability and horizontal equilibrium are controlled with the faster 50-μs cycle PID controllers. The second phase will implement a plasma-shape reconstruction algorithm and controller, aiming at optimized plasma performance. The system was designed to be as modular as possible by breaking the functional requirements of the control system into several independent and specialized modules. This splitting enabled tuning the execution of each system part and to use the modules in a variety of applications with different time constraints. This paper presents the design and overall performance of the COMPASS control software.

  19. A Field Performance Evaluation Scheme for Microwave-Absorbing Material Coatings

    Directory of Open Access Journals (Sweden)

    Shaopeng Guan

    2017-03-01

    Full Text Available Performance evaluation is an important aspect in the study of microwave-absorbing material coatings. The reflectivity of the incident wave is usually taken as the performance indicator. There have been various methods to directly or indirectly measure the reflectivity, but existing methods are mostly cumbersome and require a strict testing environment. What is more, they cannot be applied to field measurement. In this paper, we propose a scheme to achieve field performance evaluation of microwave-absorbing materials, which adopts a small H-plane sectoral horn antenna as the testing probe and a small microwave reflectometer as the indicator. When the size of the H-plane sectoral horn antenna is specially designed, the field distribution at the antenna aperture can be approximated as a plane wave similar to the far field of the microwave emitted by a radar unit. Therefore, the reflectivity can be obtained by a near-field measurement. We conducted experiments on a kind of ferrite-based microwave-absorbing material at X band (8.2–12.4 GHz to validate the scheme. The experimental results show that the reflectivity is in agreement with the reference data measured by the conventional method as a whole.

  20. A dual-task design of corrosion-controlling and osteo-compatible hexamethylenediaminetetrakis- (methylene phosphonic acid) (HDTMPA) coating on magnesium for biodegradable bone implants application.

    Science.gov (United States)

    Zhao, Sheng; Chen, Yingqi; Liu, Bo; Chen, Meiyun; Mao, Jinlong; He, Hairuo; Zhao, Yuancong; Huang, Nan; Wan, Guojiang

    2015-05-01

    Magnesium as well as its alloys appears increasingly as a revolutionary bio-metal for biodegradable implants application but the biggest challenges exist in its too fast bio-corrosion/degradation. Both corrosion-controllable and bio-compatible Mg-based bio-metal is highly desirable in clinic. In present work, hexamethylenediaminetetrakis (methylenephosphonic acid) [HDTMPA, (H2 O3 P-CH2 )2 -N-(CH2 )6 -N-(CH2 -PO3 H2 )2 ], as a natural and bioactive organic substance, was covalently immobilized and chelating-deposited onto Mg surface by means of chemical conversion process and dip-coating method, to fullfill dual-task performance of corrosion-protective and osteo-compatible functionalities. The chemical grafting of HDTMPA molecules, by participation of functional groups on pretreated Mg surface, ensured a firmly anchored base layer, and then sub-sequential chelating reactions of HDTMPA molecules guaranteed a homogenous and dense HDTMPA coating deposition on Mg substrate. Electrochemical corrosion and immersion degradation results reveal that the HDTMPA coated Mg provides a significantly better controlled bio-corrosion/degradation behavior in phosphate buffer saline solution as compared with untreated Mg from perspective of clinic requirement. Moreover, the HDTMPA coated Mg exhibits osteo-compatible in that it induces not only bioactivity of bone-like apatite precipitation but also promotes osteoblast cells adhesion and proliferation. Our well-controlled biodegradable and biocompatible HDTMPA modified Mg might bode well for next generation bone implant application. © 2014 Wiley Periodicals, Inc.

  1. Photoelectrochemical performance of NiO-coated ZnO-CdS core-shell photoanode

    Science.gov (United States)

    Iyengar, Pranit; Das, Chandan; Balasubramaniam, K. R.

    2017-03-01

    A nano-structured core-shell ZnO-CdS photoanode device with a mesoporous NiO co-catalyst layer was fabricated using solution-processing methods. The growth of the sparse ZnO nano-rod film with a thickness of ca. 930 nm was achieved by optimizing parameters such as the thickness of the ZnO seed layer, choice of Zn precursor salt and the salt concentration. CdS was then coated by a combination of spin coating and spin SILAR (Successive Ionic Layer Adsorption and Reaction) methods to completely fill the interspace of ZnO nano-rods. The uniform CdS surface facilitated the growth of a continuous mesoporous NiO layer. Upon illumination of 100 mW·cm-2 AM 1.5 G radiation the device exhibits stable photocurrents of 2.15 mA·cm-2 at 1.23 V and 0.92 mA·cm-2 at 0.00 V versus RHE, which are significantly higher as compared to the bare ZnO-CdS device. The excellent performance of the device can be ascribed to the higher visible region absorption by CdS, and effective separation of the photogenerated charge carriers due to the suitable band alignment and nanostructuring. Additionally, the mesoporous NiO overlayer offered a larger contact area with the electrolyte and promoted the kinetics enabling higher and stable photocurrent even till the 35th min. of testing.

  2. Advanced portrayal of SMIL coating by allying CZE performance with in-capillary topographic and charge-related surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Stock, Lorenz G. [Division of Chemistry and Bioanalytics, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Leitner, Michael; Traxler, Lukas [Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz (Austria); Bonazza, Klaus [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060 Vienna (Austria); Leclercq, Laurent; Cottet, Hervé [Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier (France); Friedbacher, Gernot [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060 Vienna (Austria); Ebner, Andreas [Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz (Austria); Stutz, Hanno, E-mail: hanno.stutz@sbg.ac.at [Division of Chemistry and Bioanalytics, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, Hellbrunnerstrasse 34, 5020 Salzburg (Austria)

    2017-01-25

    A successive multiple ionic polymer layer (SMIL) coating composed of four layers improved the capillary electrophoretic separation of a recombinant major birch pollen allergen and closely related variants when poly(acrylamide-co-2-acrylamido-2-methyl-1-propansulfonate) (55% PAMAMPS) replaced dextran sulfate as terminal SMIL layer. 55% PAMAMPS decelerated the electroosmotic flow (EOF) due to its lower charge density. Atomic force microscopy (AFM) was used to investigate SMIL properties directly on the inner capillary surface and to relate them to EOF measurements and results of associated CZE separations of a mixture of model proteins and peptides that were performed in the same capillary. For the first time, AFM-based biosensing topography and recognition imaging mode (TREC) under liquid conditions was applied for a sequential characterization of the inner surface of a SMIL coated capillary after selected treatments including pristine SMIL, SMIL after contact with the model mixture, after alkaline rinsing, and the replenishment of the terminal polyelectrolyte layer. A cantilever with tip-tethered avidin was used to determine the charge homogeneity of the SMIL surface in the TREC mode. SMIL coated rectangular capillaries with 100 μm internal diameter assured accessibility of the inner surface for this cantilever type. Observed changes in CZE performance and EOF mobility during capillary treatment were also reflected by alterations in surface roughness and charge distribution of the SMIL coating. A renewal of the terminal SMIL layer restored the original surface properties of SMIL and the separation performance. The alliance of the novel TREC approach and CZE results allows for an improved understanding and a comprehensive insight in effects occurring on capillary coatings. - Highlights: • SMIL coating with a terminal layer of reduced charge density improves CZE separation. • Capillaries with rectangular diameter allow for in-capillary TREC-AFM measurement.

  3. Integrated plasma control for high performance tokamaks

    International Nuclear Information System (INIS)

    Humphreys, D.A.; Deranian, R.D.; Ferron, J.R.; Johnson, R.D.; LaHaye, R.J.; Leuer, J.A.; Penaflor, B.G.; Walker, M.L.; Welander, A.S.; Jayakumar, R.J.; Makowski, M.A.; Khayrutdinov, R.R.

    2005-01-01

    Sustaining high performance in a tokamak requires controlling many equilibrium shape and profile characteristics simultaneously with high accuracy and reliability, while suppressing a variety of MHD instabilities. Integrated plasma control, the process of designing high-performance tokamak controllers based on validated system response models and confirming their performance in detailed simulations, provides a systematic method for achieving and ensuring good control performance. For present-day devices, this approach can greatly reduce the need for machine time traditionally dedicated to control optimization, and can allow determination of high-reliability controllers prior to ever producing the target equilibrium experimentally. A full set of tools needed for this approach has recently been completed and applied to present-day devices including DIII-D, NSTX and MAST. This approach has proven essential in the design of several next-generation devices including KSTAR, EAST, JT-60SC, and ITER. We describe the method, results of design and simulation tool development, and recent research producing novel approaches to equilibrium and MHD control in DIII-D. (author)

  4. Ejection Performance of Coated Core Pins Intended for Application on High Pressure Die Casting Tools for Aluminium Alloys Processing

    Directory of Open Access Journals (Sweden)

    P. Terek

    2017-09-01

    Full Text Available In high pressure die casting (HPDC process of aluminium alloys cast alloy soldering severely damages tool surfaces. It hampers casting ejection, reduces the casting quality and decreases the overall production efficiency. Thin ceramic PVD (physical vapor deposition coatings applied on tool surfaces successfully reduce these effects. However, their performance is still not recognised for surfaces with various topographies. In this investigation, soldering tendency of Al-Si-Cu alloy toward EN X27CrMoV51 steel, plasma nitrided steel, CrN and TiAlN duplex PVD coatings is evaluated using ejection test. The coatings were prepared to a range of surface roughness and topographies. After the tests sample surfaces were analysed by different microscopy techniques and profilometry. It was found that the ejection performance is independent of the chemical composition of investigated materials. After the ejection, the cast alloy soldering layer was found on surfaces of all tested materials. This built-up layer formed by effects of mechanical soldering, without corrosion reactions. Coated samples displayed a pronounced dependence of ejection force on surface roughness and topography. By decreasing roughness, ejection force increased, which is a consequence of intensified adhesion effects. Presented findings are a novel information important for efficient application of PVD coatings intendent for protection of HPDC tools.

  5. Characterising μ-AlTiN coating and assessing its performance during Ti-6Al-4V milling

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Moreno Téllez

    2013-05-01

    Full Text Available This study investigated the mechanical properties and performance of μ-AlTiN coating deposited by PVD cathodic arc technique for a specific Al0, 67Ti0, 33N composition deposited on a WC-Co and AISI D2 steel substrate. The structure of the coating was analysed using SEM, EDAX, XRD, AFM and TEM. Nano indentation measurements were used for analysing mechanical properties; the coating’s performance was evaluated during the milling of a titanium alloy (Ti6Al4V. The TiN film was initially deposited to improve adhesion between coating and substrate, where columnar grains ranging in size from 200 to 500 nm were observed having NaCl-type struc-ture. μ-AlTiN grain growth was also columnar but had ~50 nm grain size. The μ-AlTiN coated tool life was compared to an uncoated tool to determine the coating’s influence during Ti6Al4V milling. The μ-AlTiN coating improved tool life by 100% compared to that of an uncoated tool due to aluminium oxide and TiC formation on the surface and a decrease in friction coefficient between the chip and the tool.

  6. The impact of extracellular matrix coatings on the performance of human renal cells applied in bioartificial kidneys.

    Science.gov (United States)

    Zhang, Huishi; Tasnim, Farah; Ying, Jackie Y; Zink, Daniele

    2009-05-01

    Extracellular matrix (ECM) coatings have been used to improve cell performance in bioartificial kidneys (BAKs). However, their effects on primary human renal proximal tubule cells (HPTCs), which is the most important cell type with regard to clinical applications, have not been tested systematically. Also, the effects of ECM coatings on cell performance during extended time periods have not been addressed. Studying such effects is important for the development of long-term applications. Herein we analyzed for the first time systematically the effects of ECM coatings on proliferation and differentiation of human renal cells and we addressed, in particular, formation and long-term maintenance of differentiated epithelia. Our study focused on HPTCs. ECM coatings were tested alone or in combination with the growth factor bone morphogenetic protein-7 and other additives. The best results were obtained with ECMs consisting of the basal lamina components, laminin or collagen IV, and differentiated epithelia could be maintained up to three weeks on these ECMs. These results provide for the first time clear evidence which kinds of ECM coatings are most appropriate for BAKs. The results also showed that alpha-SMA-expressing myofibroblasts played a key role in the final disruption of differentiated epithelia. This suggests that epithelial-to-mesenchymal transition-related processes might be the major obstacle in long-term applications and such processes should be carefully addressed in future BAK-related research.

  7. Performance and characterisation of CVD diamond coated, sintered diamond and WC-Co cutting tools for dental and micromachining applications

    International Nuclear Information System (INIS)

    Sein, Htet; Ahmed, Waqar; Jackson, Mark; Woodwards, Robert; Polini, Riccardo

    2004-01-01

    Diamond coatings are attractive for cutting processes due to their high hardness, low friction coefficient, excellent wear resistance and chemical inertness. The application of diamond coatings on cemented tungsten carbide (WC-Co) tools was the subject of much attention in recent years in order to improve cutting performance and tool life. WC-Co tools containing 6% Co and 94% WC substrate with an average grain size 1-3 μm were used in this study. In order to improve the adhesion between diamond and WC substrates, it is necessary to etch away the surface Co and prepare the surface for subsequent diamond growth. Hot filament chemical vapour deposition with a modified vertical filament arrangement has been employed for the deposition of diamond films. Diamond film quality and purity have been characterised using scanning electron microscopy and micro-Raman spectroscopy. The performance of diamond coated WC-Co bur, uncoated WC-Co bur, and diamond embedded (sintered) bur have been compared by drilling a series of holes into various materials such as human teeth, borosilicate glass and porcelain teeth. Flank wear has been used to assess the wear rates of the tools. The materials subjected to cutting processes have been examined to assess the quality of the finish. Diamond coated WC-Co microdrills and uncoated microdrills were also tested on aluminium alloys. Results show that there was a 300% improvement when the drills were coated with diamond compared to the uncoated tools

  8. Microporous ceramic coated separators with superior wettability for enhancing the electrochemical performance of sodium-ion batteries

    Science.gov (United States)

    Suharto, Yustian; Lee, Yongho; Yu, Ji-Sang; Choi, Wonchang; Kim, Ki Jae

    2018-02-01

    Finding an alternative to glass fiber (GF) separators is a crucial factor for the fast commercialization of sodium-ion batteries (SIBs), because GF separators are too thick for use in SIBs, thereby decreasing the volumetric and gravimetric energy density. Here we propose a microporous composite separator prepared by introducing a polymeric coating layer of polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP co-polymer) with ZrO2 nanoparticles to a polyethylene (PE) separator. The coated separator efficiently enhances the cell performance of SIBs. The ZrO2 nanoparticles, finely dispersed on the polymeric coating layer, induce the formation of many micropores on the polymeric coating layer, suggesting that micropore formation on the coating layer renders the composite separator more open in structure. An ethylene carbonate/propylene carbonate liquid electrolyte for SIBs is not absorbed by PE separators even after 1 h of electrolyte droplet testing, while the proposed separator with many micropores is completely wetted by the electrolyte. Sodium ion migration across the composite separator is therefore effectively enhanced by the formation of ion transfer pathways, which improve ionic conductivity. As a result, the microporous composite separator affords stable cycle performances and excellent specific capacity retention (95.8%) after 50 cycles, comparable to those offered by a SIB with a GF separator.

  9. The SNS Resonance Control Cooling System Control Valve Upgrade Performance

    International Nuclear Information System (INIS)

    Williams, Derrick C.; Schubert, James Phillip; Tang, Johnny Y.

    2008-01-01

    The normal-conducting linac of the Spallation Neutron Source (SNS) uses 10 separate Resonance Control Cooling System (RCCS) water skids to control the resonance of 6 Drift Tube Linac (DTL) and 4 Coupled Cavity Linac (CCL) accelerating structures. The RCCS water skids use 2 control valves; one to regulate the chilled water flow and the other to bypass water to a chilled water heat exchanger. These valves have hydraulic actuators that provide position and feedback to the control system. Frequency oscillations occur using these hydraulic actuators due to their coarse movement and control of the valves. New pneumatic actuator and control positioners have been installed on the DTL3 RCCS water skid to give finer control and regulation of DTL3 cavity temperature. This paper shows a comparison of resonance control performance for the two valve configurations.

  10. Preparing high-adhesion silver coating on APTMS modified polyethylene with excellent anti-bacterial performance

    Science.gov (United States)

    Li, Wenfei; Chen, Yunxiang; Wu, Song; Zhang, Jian; Wang, Hao; Zeng, Dawen; Xie, Changsheng

    2018-04-01

    Silver coating as a broad-spectrum antimicrobial agent was considered to alleviate the inflammation caused by intrauterine device (IUD) in endometrium. In this work, to avoid the damage of silver coating and ensure its antibacterial properties, 3-aminopropyltrimethoxysilane (APTMS) was introduced to modify the polyethylene (PE) substrate for the purpose of improving the adhesion of the silver coating. From the 90° peel test, it could be found that the adhesive strength of silver coating on the APTMS modified PE substrate was nearly 23 times stronger than the silver coating on substrate without surface modification. The dramatically enhanced adhesive strength could be attributed to the formation of continuous chemical bonds between the silver coatings and substrates after surface modification, which had been confirmed by the XPS. Moreover, the standard antibacterial test revealed that the silver coated samples against Staphylococcus aureus (S. aureus) exhibit excellent antibacterial efficacy. Considering the largely enhanced adhesion and the effective antibacterial property, it is reasonable to believe that the silver coating could be considered as a potential candidate for the antibacterial agent in IUD.

  11. Application of Hard Coatings for Improved Tribological Performance of Blanking and Piercing Tools

    DEFF Research Database (Denmark)

    Podgornik, B.; Zajec, B.; Bay, Niels

    2010-01-01

    The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing applicat...

  12. Enhanced high temperature performance of LiMn2O4 coated with ...

    Indian Academy of Sciences (India)

    Cathode material, LiMn2O4, was synthesized by solid-state reaction followed by surface coating of. Li3BO3 solid ... date material for lithium ion battery due to its high voltage, ... coating of LiMn2O4 with various protective layers as Cr2O3.

  13. Enhanced electron emission from coated metal targets: Effect of surface thickness on performance

    Science.gov (United States)

    Madas, Saibabu; Mishra, S. K.; Upadhyay Kahaly, Mousumi

    2018-03-01

    In this work, we establish an analytical formalism to address the temperature dependent electron emission from a metallic target with thin coating, operating at a finite temperature. Taking into account three dimensional parabolic energy dispersion for the target (base) material and suitable thickness dependent energy dispersion for the coating layer, Fermi Dirac statistics of electron energy distribution and Fowler's mechanism of the electron emission, we discuss the dependence of the emission flux on the physical properties such as the Fermi level, work function, thickness of the coating material, and operating temperature. Our systematic estimation of how the thickness of coating affects the emission current demonstrates superior emission characteristics for thin coating layer at high temperature (above 1000 K), whereas in low temperature regime, a better response is expected from thicker coating layer. This underlying fundamental behavior appears to be essentially identical for all configurations when work function of the coating layer is lower than that of the bulk target work function. The analysis and predictions could be useful in designing new coated materials with suitable thickness for applications in the field of thin film devices and field emitters.

  14. Preparation and Performance of Plasma/Polymer Composite Coatings on Magnesium Alloy

    DEFF Research Database (Denmark)

    Bakhsheshi-Rad, H. R.; Hamzah, E.; Bagheriyan, S.

    2016-01-01

    ) that homogeneously covered the surface of the plasma layers. Contact angle measurement showed that polymer coating over plasma layers significantly decreased surface wettability. The corrosion current density (icorr) of an uncoated sample (262.7 µA/cm2) decreased to 76.9 µA/cm2 after plasma coatings were applied...

  15. Enhanced electron emission from coated metal targets: Effect of surface thickness on performance

    Directory of Open Access Journals (Sweden)

    Saibabu Madas

    2018-03-01

    Full Text Available In this work, we establish an analytical formalism to address the temperature dependent electron emission from a metallic target with thin coating, operating at a finite temperature. Taking into account three dimensional parabolic energy dispersion for the target (base material and suitable thickness dependent energy dispersion for the coating layer, Fermi Dirac statistics of electron energy distribution and Fowler’s mechanism of the electron emission, we discuss the dependence of the emission flux on the physical properties such as the Fermi level, work function, thickness of the coating material, and operating temperature. Our systematic estimation of how the thickness of coating affects the emission current demonstrates superior emission characteristics for thin coating layer at high temperature (above 1000 K, whereas in low temperature regime, a better response is expected from thicker coating layer. This underlying fundamental behavior appears to be essentially identical for all configurations when work function of the coating layer is lower than that of the bulk target work function. The analysis and predictions could be useful in designing new coated materials with suitable thickness for applications in the field of thin film devices and field emitters.

  16. Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    In this study, oxide layers generated on aluminum alloy 6060(UNS A96060) using a steam-based process were compared with conventional chromate and chromate-phosphate conversion coatings. Chemical composition and microstructure of the conversion coatings were investigated and their corrosion perfor...

  17. Effects of Graphene Monolayer Coating on the Optical Performance of Remote Phosphors

    NARCIS (Netherlands)

    Yazdan Mehr, M.; Vollebregt, S.; van Driel, W.D.; Zhang, G.Q.

    2017-01-01

    A graphene monolayer has been successfully coated on one side of a bisphenol-A-polycarbonate (BPA-PC) plate, used as a substrate for remote phosphor applications in light-emitting diode (LED)-based products. Using a photoresist transferring method, graphene sheet has been coated on BPA-PC plates.

  18. Numerical Control Device for Preparation Nano-Carbon Granule Coating Superhydrophobic Template and Its Application

    Science.gov (United States)

    Shang, G. R.; Li, Y.

    2017-12-01

    It is one of the ways for changing surface property by fabricating superhydrophibic coating with the help of template that is made of depositing nano-carbon particles of fuel flame on substrate such as pure copper or aluminium alloy. In the process of making template, it is difficult to keep the deposition layer uniformed. In this work, the problem was solved by manufacturing a set of numerical control equipment. It has been proved by application test that the deposition layer was uniformed by means of this facility. The contact angle is more than 150°. A new way has been developed for making superhydrohibic template.

  19. Control Performance Management in Industrial Automation Assessment, Diagnosis and Improvement of Control Loop Performance

    CERN Document Server

    Jelali, Mohieddine

    2013-01-01

    Control Performance Management in Industrial Automation provides a coherent and self-contained treatment of a group of methods and applications of burgeoning importance to the detection and solution of problems with control loops that are vital in maintaining product quality, operational safety, and efficiency of material and energy consumption in the process industries. The monograph deals with all aspects of control performance management (CPM), from controller assessment (minimum-variance-control-based and advanced methods), to detection and diagnosis of control loop problems (process non-linearities, oscillations, actuator faults), to the improvement of control performance (maintenance, re-design of loop components, automatic controller re-tuning). It provides a contribution towards the development and application of completely self-contained and automatic methodologies in the field. Moreover, within this work, many CPM tools have been developed that goes far beyond available CPM packages. Control Perform...

  20. Enamel coated steel reinforcement for improved durability and life-cycle performance of concrete structures: microstructure, corrosion, and deterioration

    Science.gov (United States)

    Tang, Fujian

    This study is aimed (a) to statistically characterize the corrosion-induced deterioration process of reinforced concrete structures (concrete cracking, steel mass loss, and rebar-concrete bond degradation), and (b) to develop and apply three types of enamel-coated steel bars for improved corrosion resistance of the structures. Commercially available pure enamel, mixed enamel with 50% calcium silicate, and double enamel with an inner layer of pure enamel and an outer layer of mixed enamel were considered as various steel coatings. Electrochemical tests were respectively conducted on steel plates, smooth bars embedded in concrete, and deformed bars with/without concrete cover in 3.5 wt.% NaCl or saturated Ca(OH)2 solution. The effects of enamel microstructure, coating thickness variation, potential damage, mortar protection, and corrosion environment on corrosion resistance of the steel members were investigated. Extensive test results indicated that corrosion-induced concrete cracking can be divided into four stages that gradually become less correlated with corrosion process over time. The coefficient of variation of crack width increases with the increasing level of corrosion. Corrosion changed the cross section area instead of mechanical properties of steel bars. The bond-slip behavior between the corroded bars and concrete depends on the corrosion level and distribution of corrosion pits. Although it can improve the chemical bond with concrete and steel, the mixed enamel coating is the least corrosion resistant. The double enamel coating provides the most consistent corrosion performance and is thus recommended to coat reinforcing steel bars for concrete structures applied in corrosive environments. Corrosion pits in enamel-coated bars are limited around damage locations.

  1. Effect of the addition CNTs on performance of CaP/chitosan/coating deposited on magnesium alloy by electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Pharmaceutical Research Institute in Heilongjiang Province, Jiamusi University, Jiamusi 154007 (China); Wen, Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zhao, Meng [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Guozhong, E-mail: hydlgz1962@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Dai, Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)

    2016-01-01

    CaP/chitosan/carbon nanotubes (CNTs) coating on AZ91D magnesium alloy was prepared via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The bonding between the layer and the substrate was studied by an automatic scratch instrument. The phase compositions and microstructures of the composite coatings were determined by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM). The element concentration and gentamicin concentration were respectively determined by inductively coupled plasma optical emission spectrometer (ICP-OES) test and ultraviolet spectrophotometer (UV). The cell counting kit (CCK) assay was used to evaluate the cytotoxicity of samples to SaOS-2 cells. The results showed that a few CNTs with their original tubular morphology could be found in the CaP/chitosan coating and they were beneficial for the crystal growth of phosphate and improvement of the coating bonding when the addition amount of CNTs in 500 ml of electrophoretic solution was from 0.05 g to 0.125 g. The loading amount of gentamicin increased and the releasing speed of gentamicin decreased after CNTs was added into the CaP/chitosan coating for immersion loading and EPD loading. The cell viability of Mg based CaP/chitosan/CNTs was higher than that of Mg based CaP/chitosan from 16 days to 90 days. - Highlights: • CaP/chitosan/CNTs coating on AZ91D was prepared. • The addition of CNTs could improve the performance of CaP/chitosan coating. • A new method of loading gentamicin by EPD was proposed.

  2. Synthesis and chromatographic characterization of dextran-coated zirconia high-performance liquid chromatographic stationary phases.

    Science.gov (United States)

    Dunlap, C J; Carr, P W

    1996-10-11

    Porous zirconia particles made by the oil emulsion (OE) method and the polymerization-induced colloid aggregation (PICA) method have been coated with a small, carboxymethylated (approximately 5%) dextran polymer and crosslinked in place. The parameters of the coating process (dextran concentration, adsorption time and crosslinker concentration) have all been examined and an optimum value for each determined. The coated and uncoated materials were characterized by nitrogen sorptometry and size-exclusion chromatography (SEC) using solutes (polystyrenes and dextrans) of well-defined molecular masses. Nitrogen sorptometry results show that the PICA material has a much lower pore volume and smaller pore diameter than do the OE materials. Despite this, the elution volumes of the SEC probes change very little upon polymer coating the PICA material while the OE material shows a very large change upon coating.

  3. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  4. Performance characteristics for advanced control systems

    International Nuclear Information System (INIS)

    Kisner, R.A.

    1989-01-01

    A growing collection of control techniques is becoming available to the design engineer. This make selection of the most appropriate technique for a given application a difficult task. A systematic approach to evaluating alternative control schemes is needed. The approach discussed in this paper expands the traditional concepts of quantitative performance analysis to include other relevant factors such as robustness of the technique, resource requirements, and effects on operators and other personnel. This collection of factors, termed measures of utility, may be used as qualitative and quantitative means of evaluating and comparing properties of alternative control system designs. This paper, although not an in-depth study, serves to outline several measures of utility and suggests a general structure for control system development. This method of comparing the usefulness of alternative control system will prove valuable to the ORNL Advanced Controls Program (ACTO) for optimizing compatibility with actual systems and equipment

  5. Optical Coating Performance for Heat Reflectors of the JWST-ISIM Electronic Component

    Science.gov (United States)

    Rashford, Robert A.; Perrygo, Charles M.; Garrison, Matthew B.; White, Bryant K.; Threat, Felix T.; Quijada, Manuel A.; Jeans, James W.; Huber, Frank K.; Bousquet, Robert R.; Shaw, Dave

    2011-01-01

    A document discusses a thermal radiator design consisting of lightweight composite materials and low-emittance metal coatings for use on the James Webb Space Telescope (JWST) structure. The structure will have a Thermal Subsystem unit to provide passive cooling to the Integrated Science Instrument Module (ISIM) control electronics. The ISIM, in the JWST observatory, is the platform that provides the mounting surfaces for the instrument control electronics. Dissipating the control electronic generated-heat away from JWST is of paramount importance so that the spacecraft s own heat does not interfere with the infrared-light gathering of distant cosmic sources. The need to have lateral control in the emission direction of the IEC (ISIM Electronics Compartment) radiators led to the development of a directional baffle design that uses multiple curved mirrorlike surfaces. This concept started out from the so-called Winston non-imaging optical concentrators that use opposing parabolic reflector surfaces, where each parabola has its focus at the opposite edge of the exit aperture. For this reason they are often known as compound parabolic concentrators or CPCs. This radiator system with the circular section was chosen for the IEC reflectors because it offers two advantages over other designs. The first is that the area of the reflector strips for a given radiator area is less, which results in a lower mass baffle assembly. Secondly, the fraction of energy emitted by the radiator strips and subsequently reflected by the baffle is less. These fewer reflections reduced the amount of energy that is absorbed and eventually re-emitted, typically in a direction outside the design emission range angle. A baffle frame holds the mirrors in position above a radiator panel on the IEC. Together, these will direct the majority of the heat from the IEC above the sunshield away towards empty space.

  6. Controlled drug release under a low frequency magnetic field: effect of the citrate coating on magnetoliposomes stability

    KAUST Repository

    Nappini, Silvia; Bonini, Massimo; Bombelli, Francesca Baldelli; Pineider, Francesco; Sangregorio, Claudio; Baglioni, Piero; Nordè n, Bengt

    2011-01-01

    The paper describes the effect of a low-frequency alternating magnetic field (LF-AMF) on the permeability and release properties of large (LUVs) and giant (GUVs) unilamellar vesicles loaded with citrate coated cobalt ferrite nanoparticles (NPs). The citrate shell allows a high loading of NPs in lipid vesicles without modifying their magnetic properties. The increase of magnetic LUVs permeability upon exposure to LF-AMF has been evaluated as the fluorescence self-quenching of carboxyfluorescein (CF) entrapped inside the liposome aqueous pool. Liposome leakage has been monitored as a function of field frequency, time exposure and concentration of the citrate coated NPs. Confocal Laser Scanning Microscopy (CLSM) experiments performed on magnetic GUVs labeled with the fluorescent probe DiIC18 and loaded with Alexa 488-C5-maleimide fluorescent dye provided insights on the release mechanism induced by LF-AMF. The results show that LF-AMF strongly affects vesicles permeability, suggesting the formation of pores in the lipid bilayer due to both hyperthermic effects and nanoparticle oscillations in the vesicles pool at the applied frequency. The behaviour of these magnetic vesicles in the presence of LF-AMF makes this system a good candidate for controlled drug delivery. © 2011 The Royal Society of Chemistry.

  7. Performance of vacuum plasma spray and HVOF bond coatings at 900° and 1100 °C

    Energy Technology Data Exchange (ETDEWEB)

    Lance, Michael J. [ORNL; Haynes, James A. [ORNL; Pint, Bruce A. [ORNL

    2017-12-01

    The effects of Ti and B additions to a vacuum plasma sprayed (VPS) NiCoCrAlYHfSi bond coating on thermal barrier coating (TBC) performance were studied at 1100 °C and 900 °C and compared to high-velocity oxy-fuel (HVOF) bond coatings. Using alloy 247 substrates and air plasma sprayed Y2O3-stabilized ZrO2 top coatings, additions of B or Ti + B did not improve the average TBC lifetime in 1-h cycles at 1100 °C in air with 10% H2O. The addition of Ti resulted in a decrease in lifetime. Photo-stimulated luminescence spectroscopy was used to map residual stresses in the thermally-grown Al2O3 scale. At 900 °C, closer to a typical land based turbine operating bond coating temperature, specimens were examined after ten 500-h cycles in laboratory air and air with 10%H2O to study the effect of H2O. The addition of water vapor had little effect on the measured parabolic rate constants at 900 °C and a comparison of the oxide microstructures in both environments is reported.

  8. MWCNT Coated Free-Standing Carbon Fiber Fabric for Enhanced Performance in EMI Shielding with a Higher Absolute EMI SE

    Directory of Open Access Journals (Sweden)

    Sudesh Jayashantha Pothupitiya Gamage

    2017-11-01

    Full Text Available A series of multi-walled carbon nanotube (MWCNT coated carbon fabrics was fabricated using a facile dip coating process, and their performance in electrical conductivity, thermal stability, tensile strength, electromagnetic interference (EMI and shielding effectiveness (SE was investigated. A solution of MWCNT oxide and sodium dodecyl sulfate (SDS in water was used in the coating process. MWCNTs were observed to coat the surfaces of carbon fibers and to fill the pores in the carbon fabric. Electrical conductivity of the composites was 16.42 S cm−1. An EMI shielding effectiveness of 37 dB at 2 GHz was achieved with a single layer of C/C composites, whereas the double layers resulted in 68 dB EMI SE at 2.7 GHz. Fabricated composites had a specific SE of 486.54 dB cm3 g−1 and an absolute SE of approximately 35,000 dB cm2 g−1. According to the above results, MWCNT coated C/C composites have the potential to be used in advanced shielding applications such as aerospace and auto mobile electronic devices.

  9. SYNTHESIS AND STUDY OF CORROSION PERFORMANCE OF EPOXY COATING CONTAINING MULTI-WALLED CARBON NANOTUBE/ POLY ORTHO AMINOPHENOL NANOCOMPOSITE

    Directory of Open Access Journals (Sweden)

    N. Bahrami Panah

    2016-03-01

    Full Text Available The epoxy coatings containing multi-walled carbon nanotube/ poly ortho aminophenol nanocomposite were prepared and used as anticorrosive coatings. The nanocomposites with different contents of carbon nanotube were synthesized in a solution of sodium dodecyl sulfate and ammonium peroxy disulfate as a surfactant and an oxidant, respectively. The morphology and structural properties were confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy methods. The mean size of nanocomposite particles was 20-35 nm determined by scanning electron microscopy. The epoxy coatings containing the nanocomposites were applied over mild steel panels and their corrosion performance was investigated using electrochemical impedance spectroscopy and potentiodynamic polarization measurements in a 3.5 % sodium chloride solution. The results showed that epoxy coatings consisting of nanocomposite with 1 wt.% multi-walled carbon nanotube exhibited higher anticorrosive properties than other prepared coatings of different carbon nanotube contents, which could be due to the strong interaction between the mild steel surface and the conjugated nanocomposite.

  10. Performance Analysis: Control of Hazardous Energy

    Energy Technology Data Exchange (ETDEWEB)

    De Grange, Connie E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Freeman, Jeff W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kerr, Christine E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-10-06

    LLNL experienced 26 occurrences related to the control of hazardous energy from January 1, 2008 through August 2010. These occurrences were 17% of the total number of reported occurrences during this 32-month period. The Performance Analysis and Reporting Section of the Contractor Assurance Office (CAO) routinely analyzes reported occurrences and issues looking for patterns that may indicate changes in LLNL’s performance and early indications of performance trends. It became apparent through these analyses that LLNL might have experienced a change in the control of hazardous energy and that these occurrences should be analyzed in more detail to determine if the perceived change in performance was real, whether that change is significant and if the causes of the occurrences are similar. This report documents the results of this more detailed analysis.

  11. Inclusion control in high-performance steels

    International Nuclear Information System (INIS)

    Holappa, L.E.K.; Helle, A.S.

    1995-01-01

    Progress of clean steel production, fundamentals of oxide and sulphide inclusions as well as inclusion morphology in normal and calcium treated steels are described. Effects of cleanliness and inclusion control on steel properties are discussed. In many damaging constructional and engineering applications the nonmetallic inclusions have a quite decisive role in steel performance. An example of combination of good mechanical properties and superior machinability by applying inclusion control is presented. (author)

  12. One-step preparation and photocatalytic performance of vanadium doped TiO{sub 2} coatings

    Energy Technology Data Exchange (ETDEWEB)

    Vasilić, R., E-mail: rastko.vasilic@ff.bg.ac.rs [University of Belgrade, Faculty of Physics, Studentski trg 12-16, 11000 Belgrade (Serbia); Stojadinović, S. [University of Belgrade, Faculty of Physics, Studentski trg 12-16, 11000 Belgrade (Serbia); Radić, N. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Stefanov, P. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 11, Sofia 1113 (Bulgaria); Dohčević-Mitrović, Z. [University of Belgrade, Institute of Physics, Pregrevica 118, 11080 Belgrade (Serbia); Grbić, B. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia)

    2015-02-01

    In this paper, we have investigated one-step preparation of vanadium doped TiO{sub 2} coatings formed by plasma electrolytic oxidation (PEO) of titanium in electrolyte containing 10 g/L Na{sub 3}PO{sub 4}·12H{sub 2}O + 0.5 g/L NH{sub 4}VO{sub 3}. The morphology, phase structure, and elemental composition of the formed coatings were characterized by atomic force microscopy (AFM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS) techniques. Ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS) was employed to evaluate the band gap energy of obtained coatings. Vanadium doped TiO{sub 2} coatings are partly crystallized and mainly composed of anatase phase TiO{sub 2}, with up to about 2 wt% of vanadium present in the surface layer of the oxide. The valence band photoelectron spectra and UV–Vis DRS showed that vanadium doped TiO{sub 2} coatings exhibit notable red shift with respect to the pure TiO{sub 2} coatings. The photocatalytic activity was evaluated by monitoring the degradation of methyl orange under simulated sunlight conditions. Photocatalytic activity of vanadium doped TiO{sub 2} coatings increases with PEO time. Prolonged PEO times result in higher roughness of obtained coatings, thus increasing surface area available for methyl orange degradation. Vanadium doped TiO{sub 2} coatings obtained after 180 s of PEO time exhibit the best photocatalytic activity and about 67% of methyl orange is degraded after 12 h of irradiation under simulated sunlight. - Highlights: • One-step preparation of V-doped TiO{sub 2} coatings in 10 g/L Na{sub 3}PO{sub 4}·12H{sub 2}O + 0.5 g/L NH{sub 4}VO{sub 3}. • Properties of obtained coatings strongly depend on microdischarge characteristics. • Band gap of V-doped TiO{sub 2} coatings is shifted towards red side of the spectrum. • V-doped TiO{sub 2} coatings have better photocatalytic activity than pure TiO{sub 2}. • After 12 h of simulated sunlight irradiation, 67% of

  13. One-step preparation and photocatalytic performance of vanadium doped TiO2 coatings

    International Nuclear Information System (INIS)

    Vasilić, R.; Stojadinović, S.; Radić, N.; Stefanov, P.; Dohčević-Mitrović, Z.; Grbić, B.

    2015-01-01

    In this paper, we have investigated one-step preparation of vanadium doped TiO 2 coatings formed by plasma electrolytic oxidation (PEO) of titanium in electrolyte containing 10 g/L Na 3 PO 4 ·12H 2 O + 0.5 g/L NH 4 VO 3 . The morphology, phase structure, and elemental composition of the formed coatings were characterized by atomic force microscopy (AFM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS) techniques. Ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS) was employed to evaluate the band gap energy of obtained coatings. Vanadium doped TiO 2 coatings are partly crystallized and mainly composed of anatase phase TiO 2 , with up to about 2 wt% of vanadium present in the surface layer of the oxide. The valence band photoelectron spectra and UV–Vis DRS showed that vanadium doped TiO 2 coatings exhibit notable red shift with respect to the pure TiO 2 coatings. The photocatalytic activity was evaluated by monitoring the degradation of methyl orange under simulated sunlight conditions. Photocatalytic activity of vanadium doped TiO 2 coatings increases with PEO time. Prolonged PEO times result in higher roughness of obtained coatings, thus increasing surface area available for methyl orange degradation. Vanadium doped TiO 2 coatings obtained after 180 s of PEO time exhibit the best photocatalytic activity and about 67% of methyl orange is degraded after 12 h of irradiation under simulated sunlight. - Highlights: • One-step preparation of V-doped TiO 2 coatings in 10 g/L Na 3 PO 4 ·12H 2 O + 0.5 g/L NH 4 VO 3 . • Properties of obtained coatings strongly depend on microdischarge characteristics. • Band gap of V-doped TiO 2 coatings is shifted towards red side of the spectrum. • V-doped TiO 2 coatings have better photocatalytic activity than pure TiO 2 . • After 12 h of simulated sunlight irradiation, 67% of methyl orange was decomposed

  14. Control of substrate oxidation in MOD ceramic coating on low-activation ferritic steel with reduced-pressure atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Teruya, E-mail: teru@nifs.ac.jp; Muroga, Takeo

    2014-12-15

    Highlights: • A Cr{sub 2}O{sub 3} layer was produced on a ferritic steel substrate with a reduced-pressure. • The Cr{sub 2}O{sub 3} layer prevents further substrate oxidation in following coating process. • The Cr{sub 2}O{sub 3} layer has a function as a hydrogen permeation barrier. • A smooth MOD Er{sub 2}O{sub 3} coating was successfully made on the Cr{sub 2}O{sub 3} layer by dip coating. • The Cr{sub 2}O{sub 3} layer would enhance flexibility in MOD coating process and performances. - Abstract: An Er{sub 2}O{sub 3} ceramic coating fabricated using the metal–organic decomposition (MOD) method on a Cr{sub 2}O{sub 3}-covered low-activation ferritic steel JLF-1 substrate was examined to improve hydrogen permeation barrier performance of the coating. The Cr{sub 2}O{sub 3} layer was obtained before coating by heat treating the substrate at 700 °C under reduced pressures of <5 × 10{sup −3} Pa and 5 Pa. The Cr{sub 2}O{sub 3} layer was significantly stable even with heat treatment at 700 °C in air. This layer prevented further production of Fe{sub 2}O{sub 3}, which has been considered to degrade coating performance. An MOD Er{sub 2}O{sub 3} coating with a smooth surface was successfully obtained on a Cr{sub 2}O{sub 3}-covered JLF-1 substrate by dip coating followed by drying and baking. Preprocessing to obtain a Cr{sub 2}O{sub 3} layer would provide flexibility in the coating process for blanket components and ducts. Moreover, the Cr{sub 2}O{sub 3} layer suppressed hydrogen permeation through the JLF-1 substrate. While further optimization of the coating fabrication process is required, it would be possible to suppress hydrogen permeation significantly by multilayers of Cr{sub 2}O{sub 3} and MOD oxide ceramic.

  15. Low Conductive Thermal Barrier Coatings Produced by Ion Beam Assisted EB-PVD with Controlled Porosity, Microstructure Refinement and Alloying Additions for High Temperature Applications

    Science.gov (United States)

    Wolfe, Douglas E.; Singh, Jogender

    2005-01-01

    Various advanced Hafnia-based thermal barrier coatings (TBC) were applied on nickel-based superalloy coupons by electron beam physical vapor deposition. In addition, microstructural modifications to the coating material were made in an effort to reduce the thermal conductivity of the coating materials. Various processing parameters and coating system modifications were made in order to deposit the alloyed TBC with the desired microstructure and thus coating performance, some of which include applying coatings at substrate temperatures of 1150 C on both PtAl and CoNiCrAlY bond coated samples, as well as using 8YSZ as a bond layer. In addition, various characterization techniques including thermal cyclic tests, scanning electron microscopy, x-ray diffraction, thermal conductivity, and reflectivity measurements were performed. Although the coating microstructure was never fully optimized due to funding being cut short, significant reductions in thermal conductivity were accomplished through both chemistry changes (composition) and microstructural modifications.

  16. Performance of a polymer sealant coating in an arctic marine environment

    International Nuclear Information System (INIS)

    Moskowitz, P.; Cowgill, M.; Griffith, A.; Chernaenko, L.; Diashev, A.; Nazarian, A.

    2001-01-01

    The feasibility of using a polymer-based coating, Polibrid 705, to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment has been successfully demonstrated using a combination of field and laboratory testing. A mobile, self-sufficient spraying device was developed to specifications provided by the Russian Northern Navy and deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading dock. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors, exposed to the full annual Arctic weather cycle. The 12 months of field testing gave rise to little degradation of the sealant coating, except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. The field tests were accompanied by a series of laboratory qualification tests carried out at a research laboratory in St. Petersburg. The laboratory tests examined a variety of properties, including bond strength between the coating and the substrate, thermal cycling resistance, wear resistance, flammability, and ease of decontamination. The Polibrid 705 coating met all the Russian Navy qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities

  17. Pesticidal seed coats based on azadirachtin-A: release kinetics, storage life and performance.

    Science.gov (United States)

    Nisar, Keyath; Kumar, Jitendra; Arun Kumar, M B; Walia, Suresh; Shakil, Najam A; Parsad, Rajender; Parmar, Balraj S

    2009-02-01

    Infestation of seeds by pests during storage leads to deterioration in quality. Seed coating is an effective option to overcome the menace. Unlike synthetic fungicidal seed coats, little is known of those based on botanicals. This study aims at developing azadirachtin-A-based pesticidal seed coats to maintain seed quality during storage. Polymer- and clay-based coats containing azadirachtin-A were prepared and evaluated for quality maintenance of soybean seed during storage. Gum acacia, gum tragacanth, rosin, ethyl cellulose, hydroxyethyl cellulose, polyethyl methacrylate, methyl cellulose, polyethylene glycol, polyvinyl chloride, polyvinyl acetate, polyvinyl pyrrolidone and Agrimer VA 6 polymers and the clay bentonite were used as carriers. The time for 50% release (t(1/2)) of azadirachtin-A into water from the seeds coated with the different coats ranged from 8.02 to 21.36 h. The half-life (T(1/2)) of azadirachtin-A in the coats on seed ranged from 4.37 to 11.22 months, as compared with 3.45 months in azadirachtin-A WP, showing an increase by a factor of nearly 1.3-3.3 over the latter. The coats apparently acted as a barrier to moisture to reduce azadirachtin-A degradation and prevented proliferation of storage fungi. Polyethyl methacrylate, polyvinyl acetate and polyvinyl pyrrolidone were significantly superior to the other polymers. Azadirachtin-A showed a significant positive correlation with seed germination and vigour, and negative correlation with moisture content. Effective polymeric carriers for seed coats based on azadirachtin-A are reported. These checked seed deterioration during storage by acting as a barrier to moisture and reduced the degradation of azadirachtin-A.

  18. Characterization and temperature controlling property of TiAlN coatings deposited by reactive magnetron co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.T. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Wang, J. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); National Key Laboratory of Surface Engineering, Lanzhou Institute of Physics, Lanzhou 730000 (China); Zhang, F.; Zhang, G.A.; Fan, X.Y.; Wu, Z.G. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Yan, P.X. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute Chemical and Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: pxyan@lzu.edu.cn

    2009-03-20

    Titanium aluminum nitride (TiAlN) ternary coating is a potential material which is expected to be applied on satellite for thermal controlling. In order to investigate thermal controlling property, TiAlN coatings were deposited on Si wafers with different N{sub 2} and Ar flux ratio by reactive magnetron co-sputtering. The structure, morphology, chemical composition and optical reflectance are investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), atom force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and spectrophotometer, respectively. The orientation of the coatings depends on the N{sub 2}/Ar flux ratio. The coatings deposited with N{sub 2}/Ar ratio of 10, 30 and 60% show the cubic-TiN [2 2 0] preferred orientation and the coating deposited with N{sub 2}/Ar ratio of 100% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of the coatings becomes more compact and smoother with the N{sub 2}/Ar ratios increase. XPS spectrum indicates that the oxides (TiO{sub 2} and Al{sub 2}O{sub 3}), oxynitride (TiN{sub x}O{sub y}) and nitrides (TiN and AlN{sub x}) appear at the surface of the coatings. Ignoring internal power, the optimum equilibrium temperature of TiAlN coatings is 18 deg. C and the equilibrium temperature after heat-treated has slight change, which provides the prospective application on thermal controlling.

  19. Enhancement of osteogenesis and biodegradation control by brushite coating on Mg-Nd-Zn-Zr alloy for mandibular bone repair.

    Science.gov (United States)

    Guan, Xingmin; Xiong, Meiping; Zeng, Feiyue; Xu, Bin; Yang, Lingdi; Guo, Han; Niu, Jialin; Zhang, Jian; Chen, Chenxin; Pei, Jia; Huang, Hua; Yuan, Guangyin

    2014-12-10

    To diminish incongruity between bone regeneration and biodegradation of implant magnesium alloy applied for mandibular bone repair, a brushite coating was deposited on a matrix of a Mg-Nd-Zn-Zr (hereafter, denoted as JDBM) alloy to control the degradation rate of the implant and enhance osteogenesis of the mandible bone. Both in vitro and in vivo evaluations were carried out in the present work. Viability and adhesion assays of rabbit bone marrow mesenchyal stem cells (rBM-MSCs) were applied to determine the biocompatibility of a brushite-coated JDBM alloy. Osteogenic gene expression was characterized by quantitative real-time polymerase chain reaction (RT-PCR). Brushite-coated JDBM screws were implanted into mandible bones of rabbits for 1, 4, and 7 months, respectively, using 316L stainless steel screws as a control group. In vivo biodegradation rate was determined by synchrotron radiation X-ray microtomography, and osteogenesis was observed and evaluated using Van Gieson's picric acid-fuchsin. Both the naked JDBM and brushite-coated JDBM samples revealed adequate biosafety and biocompatibility as bone repair substitutes. In vitro results showed that brushite-coated JDBM considerably induced osteogenic differentiation of rBM-MSCs. And in vivo experiments indicated that brushite-coated JDBM screws presented advantages in osteoconductivity and osteogenesis of mandible bone of rabbits. Degradation rate was suppressed at a lower level at the initial stage of implantation when new bone tissue formed. Brushite, which can enhance oeteogenesis and partly control the degradation rate of an implant, is an appropriate coating for JDBM alloys used for mandibular repair. The Mg-Nd-Zn-Zr alloy with brushite coating possesses great potential for clinical applications for mandibular repair.

  20. Carbon-coated NiPt, CoPt nanoalloys: size control and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    El-Gendy, A.A. [Kirchhoff Institute for Physics, University of Heidelberg, D-69120 Heidelberg (Germany); Leibniz Institute for Solid State and Materials Research (IFW) Dresden (Germany); Hampel, S.; Leonhardt, A.; Khavrus, V.; Buechner, B. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden (Germany); Klingeler, R. [Kirchhoff Institute for Physics, University of Heidelberg, D-69120 Heidelberg (Germany)

    2011-07-01

    Controlled synthesis of magnetic nanoparticles with well-defined size and composition is always a challenge in material-based nanoscience. Here, we apply the high pressure chemical vapour deposition technique (HPCVD) to obtain carbon-shielded magnetic alloy nanoparticles under control of the particle size. Carbon encapsulated NiPt, CoPt (NiPt rate at C, CoPt rate at C) nanoalloys were synthesized by means of HPCVD starting from sublimating appropriate metal-organic precursors. Structural characterization by means of high resolution transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction indicated the formation of coated bimetallic Ni{sub x}Pt{sub 100-x} and CoxPt{sub 100-x} nanoparticles. Adjusting the sublimation temperature of the different precursors allowed tuning the core sizes with small size distribution. In addition, detailed studies of the magnetic properties are presented. AC magnetic heating studies imply the potential of the coated nanoalloys for hyperthermia therapy.

  1. On the Cutting Performance of Coated HSS Taps When Machining of Austenitic Steel

    Science.gov (United States)

    Sliwkova, Petra; Piska, Miroslav

    2014-12-01

    The paper deals with a quality of the PVD coated HSS taps when cutting the stainless austenitic chromiumnickel non-stabilized steel DIN 1.4301 (X5CrNi 18-10). The main attention is focused on the analysis of loading (cutting moment, specific energy) of the HSS taps by means of pieso-electrical dynamometer Kistler 9272 and the relation between the quality of duplex and triplex PVD coatings and their effects on the quality of machined thread surfaces and tool life of the taps. The results showed a safe and stabilized cutting with acceptable quality of threads for HSSE with the TiN+TiCN+DLC coating.

  2. Protective coating as a factor to ensure the strength and hydraulic performance of recoverable pipelines

    Directory of Open Access Journals (Sweden)

    Orlov Vladimir Aleksandrovich

    2015-01-01

    Full Text Available The authors present an analysis of various types of internal protective pipeline coatings to ensure the strength and hydraulic characteristics of a remodeled pipeline and related coating methods for effective trenchless renovation of engineering systems, water supply systems and sanitation. As protective coating the authors considered a round profile tube of a smaller diameter than of the old pipe, close to the old pipe, sprayed lining on the basis of inorganic and inorganic materials. The article analyzes the methods of trenchless renovation for applying protective coatings: routing in the old pipeline of new pipes made of polymeric materials or polymeric sleeves, centrifugal spraying on the inner surface of pipelines’ inorganic and organic protective coatings. Special attention was paid to bag technology, providing the required strength properties at specific values of the modulus of elasticity and a number of external factors such as the depth of the existing pipe, the existence and magnitude of the horizon groundwater over it. Also attention is paid to the application technology of tape coatings ribbed profile on the inner surface of pipelines. This technology has a unique feature, which is the ability of recoverable pipeline functioning during its renovation by winding an endless belt and the formation of a new pipe. The tape coating winding is carried out by different types of spiral winding machines. The thickness of the protective coating layer forming the tube remains minimal. Inorganic cement-sand and organic coatings were considered as alternative options for repair of pipelines, which allow to localize the defects in the form of a fistula, minor cracks and other damages. However it is noted that a cement-sandy covering is inferior to organic, because it does not provide the strength characteristics of the pipeline system. The main advantage of the organic coating is mudding fistula of a large diameter, making a high wear

  3. Neutral hydrophilic coatings for capillary electrophoresis prepared by controlled radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Fabián H.; Gómez, Jorge E.; Espinal, José H.; Sandoval, Junior E., E-mail: junior.sandoval@correounivalle.edu.co

    2016-12-15

    In the present study, porous silica particles as well as impervious fused-silica wafers and capillary tubes were modified with hydrophilic polymers (hydroxylated polyacrylamides and polyacrylates), using a surface-confined grafting procedure based on atom transfer radical polymerization (ATRP) which was also surface-initiated from α-bromoisobutyryl groups. Initiator immobilization was achieved by hydrosilylation of allyl alcohol on hydride silica followed by esterification of the resulting propanol-bonded surface with α-bromoisobutyryl bromide. Elemental analysis, IR and NMR spectroscopies on silica micro-particles, atomic force microscopy, ellipsometry and profilometry on fused-silica wafers, as well as CE on fused-silica tubes were used to characterize the chemically modified silica substrate at different stages. We studied the effect of monomer concentration as well as cross-linker on the ability of the polymer film to reduce electroosmosis and to prevent protein adsorption (i. e., its non-fouling capabilities) and found that the former was rather insensitive to both parameters. Surface deactivation towards adsorption was somewhat more susceptible to monomer concentration and appeared also to be favored by a low concentration of the cross-linker. The results show that hydrophilic polyacrylamide and polyacrylate coatings of controlled thickness can be prepared by ATRP under very mild polymerization conditions (aqueous solvent, room temperature and short reaction times) and that the coated capillary tubes exhibit high efficiencies for protein separations (0.3–0.6 million theoretical plates per meter) as well as long-term hydrolytic stability under the inherently harsh conditions of capillary isoelectric focusing. Additionally, there was no adsorption of lysozyme on the coated surface as indicated by a complete recovery of the basic enzyme. Furthermore, since polymerization is confined to the inner capillary surface, simple precautions (e.g., solution

  4. Plasma-spraying synthesis of high-performance photocatalytic TiO2 coatings

    International Nuclear Information System (INIS)

    Takahashi, Yasuo; Maeda, Masakatsu; Ohmori, Akira; Shibata, Yoshitaka; Miyano, Yasuyuki; Murai, Kensuke

    2014-01-01

    Anatase (A-) TiO 2 is a photocatalytic material that can decompose air-pollutants, acetaldehyde, bacteria, and so on. In this study, three kinds of powder (A-TiO 2 without HAp, TiO 2 + 10mass%HAp, and TiO 2 +30mass%HAp, where HAp is hydroxyapatite and PBS is polybutylene succinate) were plasma sprayed on biodegradable PBS substrates. HAp powder was mixed with A-TiO 2 powder by spray granulation in order to facilitate adsorption of acetaldehyde and bacteria. The crystal structure was almost completely maintained during the plasma spray process. HAp enhanced the decomposition of acetaldehyde and bacteria by promoting adsorption. A 10mass% HAp content was the most effective for decomposing acetaldehyde when plasma preheating of the PBS was not carried out before the plasma spraying. The plasma preheating of PBS increased the yield rate of the spray process and facilitated the decomposition of acetaldehyde by A-TiO 2 coatings without HAp. HAp addition improved photocatalytic sterilization when plasma preheating of the PBS was performed

  5. An investigation on the performance characteristics of solar flat plate collector with different selective surface coatings

    Energy Technology Data Exchange (ETDEWEB)

    Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

    2012-07-01

    In the present work, investigations are made to study performance characteristics of solar flat plate collector with different selective surface coatings. Flat plate collector is one of the important solar energy trapping device which uses air or water as working fluid. Of the many solar collector concepts presently being developed, the relative simple flat plate solar collector has found the widest application so far. Its characteristics are known, and compared with other collector types, it is the easiest and least expensive to fabricate, install, and maintain. Moreover, it is capable of using both the diffuse and the direct beam solar radiation. For residential and commercial use, flat plate collectors can produce heat at sufficiently high temperatures to heat swimming pools, domestic hot water, and buildings; they also can operate a cooling unit, particularly if the incident sunlight is increased by the use of reflector. Temperatures up to 70 C are easily attained by flat plate collectors. With very careful engineering using special surfaces, reflectors to increase the incident radiation and heat resistant materials, higher operating temperatures are feasible.

  6. Synthesis and Electrochemical Performance of SiOC-Carbon Nanotube Composite Coatings

    Science.gov (United States)

    Bhandavat, Romil; Cologna, Marco; Raj, Rishi; Singh, Gurpreet

    2012-02-01

    Rechargeable battery anodes made from crystalline Si-based nanostructures have been shown to possess high experimental first cycle capacities (3000 mAh/g), but face challenges in sustaining these capacities beyond initial cycles mainly due to large volume expansion (400 percent) and chemical degradation (pulverization). Polymer-derived ceramic SiOC due to its high thermodynamic stability and nano domain structure could present a viable alternative. Additionally, functionalization of SiOC with carbon nanotubes could result in increased electronic and ionic conductivities in the ceramic. Here, we demonstrate synthesis and electrochemical characterization of SiOC-CNT composite coatings for use in Li-ion battery anode. Materials characterization performed using electron microscopy, Infrared (FT-IR), and X-ray photoelectron spectroscopy suggests non-covalent functionalization of CNT with oxygen moieties in SiOC. Sustained battery capacities of over 700 mAh/g and first cycle columbic efficiencies of about 75 percent were achieved. Future work will involve determination of lithium ion intercalation sites characterized by electron microscopy whereas cyclic voltammetry analysis will access the sequential change in anode chemistry.

  7. Assessment of Environmental Performance of TiO2 Nanoparticles Coated Self-Cleaning Float Glass

    Directory of Open Access Journals (Sweden)

    Martina Pini

    2017-01-01

    Full Text Available In recent years, superhydrophilic and photocatalytic self-cleaning nanocoatings have been widely used in the easy-to-clean surfaces field. In the building sector, self-cleaning glass was one of the first nanocoating applications. These products are based on the photocatalytic property of a thin layer of titanium dioxide (TiO2 nanoparticles deposited on the surface of any kind of common glass. When exposed to UV radiation, TiO2 nanoparticles react with the oxygen and water molecules adsorbed on their surface to produce radicals leading to oxidative species. These species are able to reduce or even eliminate airborne pollutants and organic substances deposited on the material’s surface. To date, TiO2 nanoparticles’ benefits have been substantiated; however, their ecological and human health risks are still under analysis. The present work studies the ecodesign of the industrial scale-up of TiO2 nanoparticles self-cleaning coated float glass production performed by the life cycle assessment (LCA methodology and applies new human toxicity indicators to the impact assessment stage. Production, particularly the TiO2 nanoparticle application, is the life cycle phase most contributing to the total damage. According to the ecodesign approach, the production choices carried out have exacerbated environmental burdens.

  8. Facile coating of manganese oxide on tin oxide nanowires with high-performance capacitive behavior.

    Science.gov (United States)

    Yan, Jian; Khoo, Eugene; Sumboja, Afriyanti; Lee, Pooi See

    2010-07-27

    In this paper, a very simple solution-based method is employed to coat amorphous MnO2 onto crystalline SnO2 nanowires grown on stainless steel substrate, which utilizes the better electronic conductivity of SnO2 nanowires as the supporting backbone to deposit MnO2 for supercapacitor electrodes. Cyclic voltammetry (CV) and galvanostatic charge/discharge methods have been carried out to study the capacitive properties of the SnO2/MnO2 composites. A specific capacitance (based on MnO2) as high as 637 F g(-1) is obtained at a scan rate of 2 mV s(-1) (800 F g(-1) at a current density of 1 A g(-1)) in 1 M Na2SO4 aqueous solution. The energy density and power density measured at 50 A g(-1) are 35.4 W h kg(-1) and 25 kW kg(-1), respectively, demonstrating the good rate capability. In addition, the SnO2/MnO2 composite electrode shows excellent long-term cyclic stability (less than 1.2% decrease of the specific capacitance is observed after 2000 CV cycles). The temperature-dependent capacitive behavior is also discussed. Such high-performance capacitive behavior indicates that the SnO2/MnO2 composite is a very promising electrode material for fabricating supercapacitors.

  9. Optical performance evolutions of reductive glutathione coated CdSe quantum dots in different environments

    International Nuclear Information System (INIS)

    Wang Lili; Jiang Jisen

    2011-01-01

    Optical performances of reductive glutathione coated CdSe quantum dots were studied under different ageing conditions. The enhancements of luminescence were obviously occurred for the samples ageing under illumination. The quantum yield of CdSe was enhanced continuously over 44 days at room temperature, and reached as high as 36.6%. O 2 was proved to make a certain contribute to the enhancement. The evolutions of the systems during the ageing time were deduced according to the variations of pH values with ageing time and the XRD results of the samples ageing in air with illumination. We conferred that the reduction of surface defects resulted from the photo-induced decomposition of CdSe quantum dots was the main reason for the enhancement of fluorescence. The production of CdO as a result of the surface reaction with O 2 made contributions to the enhancement for a certain extent. The curves of quantum yield versus ageing time were fitted with a stretched exponential function. It was found that the course of fluorescence enhancement accorded with the dynamics of system with strongly coupled hierarchical degrees of freedom.

  10. Network performance for graphical control systems

    International Nuclear Information System (INIS)

    Clout, P.; Geib, M.; Westervelt, R.

    1992-01-01

    Vsystem is a toolbox for building graphically-based control systems. The real-tiem database component, Vaccess, includes all the networking support necessary to build multi-computer control systems. Vaccess has two modes of database access, synchronous and asynchronous. Vdraw is another component of Vsystem that allows developers and users to develop control screens and windows by drawing rather than programming. Based on X-windows, Vsystem provides the possibility of running Vdraw either on the workstation with the graphics or on the computer with the database. We have made some measurements on the cpu loading, elapsed time and the network loading to give some guidance in system configuration performance. It will be seen that asynchronous network access gives large performance increases and that the network database change notification protocol can be either more or less efficient than the X-window network protocol, depending on the graphical representation of the data. (author)

  11. PATINA Network - Performance of coil coating in natural atmospheres of Ibero-America

    Directory of Open Access Journals (Sweden)

    Rosales, B. M.

    2003-12-01

    Full Text Available The research work performed on 12 coil coating materials in the frame of the PATINA Network (Anticorrosive Protection in the Atmosphere sponsored by CYTED is discussed. It includs the task accomplished by Science and Technology institutions of Ibero-America on formulations supplied by different prcoduction Sector companies from the participating countries, between 1996 and 2000. Coil coating schemes were exposed outdoors, according to ISO 2810 standards, in 9 ambient conditions of the MICAT (Ibero-American Test Stations Network, CYTED. The protective characteristics on the steel base metal was determined as a function of time, following ISO 4628 and ASTM D 3274 standards. Electrochemical impedance spectroscopy (EIS was applied on various materials after 1, 2, 3 years and 42 months exposure, to evaluate the weathering effect in different atmospheric conditions.

    Se discute el trabajo realizado sobre 12 diferentes recubrimientos para banda continua en el marco de la Red PATINA (Protección Anticorrosiva en la Atmósfera, patrocinada por el CYTED. Incluye las actividades llevadas a cabo por instituciones de Ciencia y Técnica de Iberoamérica, sobre distintas formulaciones provistas por empresas productoras de los países participantes, entre 1996 y 1999. Se expusieron a la intemperie, en distintas condiciones ambientales de la Red de Estaciones MICAT, CYTED, siguiendo la norma ISO 2810, recubrimientos de diferentes formulaciones. Se evaluaron las características protectoras sobre el acero de base en función de los parámetros medio-ambientales y los tiempos de exposición programados, según la normas ISO 4628, 4623 y ASTM D 3274. Se aplicaron dos esquemas de protección orgánicos sobre las muestras de acero, otros cuatro sobre muestras de acero previamente protegido con Zn y otros seis sobre acero galvanizado (2 y recubierto con galvalume (4, con y sin incisión en cada esquema hasta llegar el acero. Se discuten los resultados obtenidos

  12. Acceleration of aneurysm healing by P(DLLA-co-TMC)-coated coils enabling the controlled release of vascular endothelial growth factor

    International Nuclear Information System (INIS)

    Wang, Qiujing; Gao, Yuyuan; Sun, Xinlin; Ji, Bin; Cui, Xubo; Liu, Yaqi; Zheng, Tao; Chen, Chengwei; Jiang, Xiaodan; Zhu, Aiping; Quan, Daping

    2014-01-01

    Since the introduction of the detachable coil in endovascular treatment of intracranial aneurysms, the in-hospital mortality rate has been significantly decreased. Recurrence of the aneurysm remains the major drawback of using detachable coils. We prepared a bioactive coil coated with poly(d,l-lactide)-7co-(1,3-trimethylene carbonate) (P(DLLA-co-TMC)), a novel copolymer for controlling the release of vascular endothelial growth factor (VEGF). Platinum coils were prepared by successive coating with cationic P(DLLA-co-TMC) and anionic heparin. Then, recombinant human VEGF-165 (rhVEGF) was immobilized by affinity binding to heparin. The morphological characteristics and sustained in vitro release of rhVEGF were examined using scanning electron microscopy and enzyme-linked immunosorbent assay, respectively. The efficacy of these novel coils modified by P(DLLA-co-TMC)/rhVEGF was tested using a common carotid artery aneurysm model in rats. Experimental aneurysms were embolized with unmodified, P(DLLA-co-TMC)/heparin-coated or P(DLLA-co-TMC)/rhVEGF-coated platinum coils (n = 18). The coils were removed on days 15, 30 and 90 after insertion, and the histological and immunohistochemical analysis of factor VIII was performed to confirm the presence of endothelial cells in the organized area. In addition, the controlled in vivo release of VEGF was confirmed by Western blotting analysis. The release of VEGF tended to increase during the whole period and no burst release was observed. In the group treated with P(DLLA-co-TMC)/rhVEGF-coated platinum coils, clot organization and endothelial cell proliferation were accelerated. The immunohistochemistry study showed that the expression of factor VIII was found in the P(DLLA-co-TMC)/rhVEGF-coated coil group but not in the other two groups. Furthermore, Western blotting analysis confirmed that the major released VEGF in the aneurysm sac was from the P(DLLA-co-TMC)/VEGF-coated coil. P(DLLA-co-TMC)/rhVEGF-coated platinum coils can

  13. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink Devices will increase the efficiency of multi-junction solar cells by designing and demonstrating advanced anti-reflection coatings (ARCs) that will...

  14. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink and its subcontractor Magnolia Solar will develop and demonstrate advanced anti-reflection coating (ARC) designs that will provide a better broadband and...

  15. Splice performance evaluation of enamel-coated rebar for structural safety.

    Science.gov (United States)

    2014-07-01

    This report summarizes the findings and results from an experimental study of vitreous enamel coating effects on the bond : strength between deformed rebar and normal strength concrete. A total of 24 beam splice specimens were tested under four-point...

  16. Cross Coating Weight Control by Electromagnetic Strip Stabilization at the Continuous Galvanizing Line of ArcelorMittal Florange

    Science.gov (United States)

    Guelton, Nicolas; Lopès, Catherine; Sordini, Henri

    2016-08-01

    In hot dip galvanizing lines, strip bending around the sink roll generates a flatness defect called crossbow. This defect affects the cross coating weight distribution by changing the knife-to-strip distance along the strip width and requires a significant increase in coating target to prevent any risk of undercoating. The already-existing coating weight control system succeeds in eliminating both average and skew coating errors but cannot do anything against crossbow coating errors. It has therefore been upgraded with a flatness correction function which takes advantage of the possibility of controlling the electromagnetic stabilizer. The basic principle is to split, for every gage scan, the coating weight cross profile of the top and bottom sides into two, respectively, linear and non-linear components. The linear component is used to correct the skew error by realigning the knives with the strip, while the non-linear component is used to distort the strip in the stabilizer in such a way that the strip is kept flat between the knives. Industrial evaluation is currently in progress but the first results have already shown that the strip can be significantly flattened between the knives and the production tolerances subsequently tightened without compromising quality.

  17. PERFORMANCE ANALYSIS OF 1,4 DIOXANE-ETHANOL-DIESEL BLENDS ON DIESEL ENGINES WITH AND WITHOUT THERMAL BARRIER COATING

    Directory of Open Access Journals (Sweden)

    Chockalingam Sundar Raj

    2010-01-01

    Full Text Available 1,4 dioxane, a new additive allows the splash blending of ethanol in diesel in a clear solution. The objective of this investigation is to first create a stable ethanol-diesel blended fuel with 10% 1,4 dioxane additive, and then to generate performance, combustion and emissions data for evaluation of different ethanol content on a single cylinder diesel engine with and without thermal barrier coating. Results show improved performance with blends compared to neat fuel for all conditions of the engine. Drastic reduction in smoke density is found with the blends as compared to neat diesel and the reduction is still better for coated engine. NOx emissions were found to be high for coated engines than the normal engine for the blends. The oxygen enriched fuel increases the peak pressure and rate of pressure rise with increase in ethanol ratio and is still superior for coated engine. Heat release pattern shows higher premixed combustion rate with the blends. Longer ignition delay and shorter combustion duration are found with all blends than neat diesel fuel.

  18. Synthetic lubrication oil influences on performance and emission characteristic of coated diesel engine fuelled by biodiesel blends

    International Nuclear Information System (INIS)

    Mohamed Musthafa, M.

    2016-01-01

    Highlights: • Synthetic lubricant provides the maximum performance benefits. • Synthetic lubricant is capable of retaining satisfactory viscosity. • Synthetic lubricant is to increase the life of the engine. • Improvement in efficiency of the coated engine with synthetic lubrication. • No significant changes in the coated engine emission with synthetic lubricants. - Abstract: In this study, the effects of using synthetic lubricating oil on the performance and exhaust emissions in a low heat rejection diesel engine running on Pongamia methyl ester blends and diesel have been investigated experimentally compared to those obtained from a conventional diesel engine with SAE 40 lubrication oil fuelled by diesel. For this purpose, direct injection diesel engine was converted to Yttria-stabilized zirconia (YSZ) coated engine. The results showed 5–9% increase in engine efficiency and 8–17% decrease in specific fuel consumption, as well as significant improvements in exhaust gas emissions (except NO_X) for all tested fuels (pure diesel, B10 and B20) used in coated engine with synthetic lubricants compared to that of the uncoated engine with SAE 40 lubricant running on diesel fuel.

  19. Comparing the Electrochemical Performance of LiFePO4/C Modified by Mg Doping and MgO Coating

    Directory of Open Access Journals (Sweden)

    Jianjun Song

    2013-01-01

    Full Text Available Supervalent cation doping and metal oxide coating are the most efficacious and popular methods to optimize the property of LiFePO4 lithium battery material. Mg-doped and MgO-coated LiFePO4/C were synthesized to analyze their individual influence on the electrochemical performance of active material. The specific capacity and rate capability of LiFePO4/C are improved by both MgO coating and Mg doping, especially the Mg-doped sample—Li0.985Mg0.015FePO4/C, whose discharge capacity is up to 163 mAh g−1, 145.5 mAh g−1, 128.3 mAh g−1, and 103.7 mAh g−1 at 1 C, 2 C, 5 C, and 10 C, respectively. The cyclic life of electrode is obviously increased by MgO surface modification, and the discharge capacity retention rate of sample LiFePO4/C-MgO2.5 is up to 104.2% after 100 cycles. Comparing samples modified by these two methods, Mg doping is more prominent on prompting the capacity and rate capability of LiFePO4, while MgO coating is superior in terms of improving cyclic performance.

  20. Comparative crossover controlled study using poly sulphone and Vitamin E coated dialyzers

    International Nuclear Information System (INIS)

    Al-Jonderby, Mohammad S.; Cabaguing, IoIani; Pajarillo, Amillata A.

    2003-01-01

    There is relatively little clinical experience reported on the use of vitamin E coated dialyzer (CL-EE 12, Terumo). This study compares its efficacy and intradialytic symptoms with a poly sulphone dialyzer in 2 group of patients in a controlled crossover trial design. This study was carried out at at Armed Forces Hospital, Riyadh, Kingdom of Saudi Arabia, during time period from January to March 2002. In group A, 34 patients were dialyzed for 4 weeks with vitamin E dialyzer and then switched over to Fresenius 60 ( F60)for 4 weeks .In group B, 41 patients were dialyzed with F60 for 4 weeks then switched over to vitamin E coated dialyzers for 4 weeks .The following parameters were measured weekly ,hemoglobin level ,urea reduction ratio (URR), urea clarence ratio (Kt/V), pre and post dialysis diastolic blood pressure (DBP)and diastolic blood pressure (DBP), interdialytic weight gain. The patients were observed for interdialytic hypertension or symptoms.No significant findings were found in any of the parameters except more dialyzer clotting was observed with vitamin E dialyzer than in F60 dialyzers(1.6%of dialysis sessions versus 0.1% P<0.03).The interdialytic weight gain tended to be less in vitamin E group but did not reach statistically significant difference.The Kt / V and URR were slightly higher when using vitamin E dialyzer only in the second and third weeks hypotensive episodes( P<,007)less leg cramp (P<.31) and less itching (P<,0.2) in the vitamin E coated treated group within group. There were only minor differences noted between between the 2 dialyzers in the parameters measured. (author)

  1. Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Sheng-xue Yu

    2013-01-01

    Full Text Available Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF6 0.75 g·L−1, NaF 1.25 g·L−1, MgSO4 1.0 g/L, and tetra-n-butyl titanate (TBT 0.08 g·L−1. X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectrum (FT-IR were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM and scanning electron microscopy (SEM. Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS. Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is 9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment.

  2. Enhanced Shielding Performance of HLW Storage Packages via Multi- Component Coatings

    International Nuclear Information System (INIS)

    Winfrey, Leigh

    2017-01-01

    The steel coatings developed here prevent water, dirt, and chemical contaminants from the atmosphere or soil from making contact with waste packages that would damage and weaken them during long-term storage. In addition, through this project we demonstrated that a range of coatings have this capability, will survive in the environment they will be used in, and can be deposited readily on large surfaces which is critical for their use in waste storage.

  3. Enhanced Shielding Performance of HLW Storage Packages via Multi- Component Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Winfrey, Leigh [Univ. of Florida, Gainesville, FL (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2017-10-02

    The steel coatings developed here prevent water, dirt, and chemical contaminants from the atmosphere or soil from making contact with waste packages that would damage and weaken them during long-term storage. In addition, through this project we demonstrated that a range of coatings have this capability, will survive in the environment they will be used in, and can be deposited readily on large surfaces which is critical for their use in waste storage.

  4. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances

    DEFF Research Database (Denmark)

    Zhang, X.G.; Zhang, X.D.; He, W.

    2012-01-01

    We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries.......We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries....

  5. Reduction of coating induced polarization aberrations by controlling the polarization state variation

    International Nuclear Information System (INIS)

    Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

    2011-01-01

    The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

  6. High performance W-AIN cermet solar coatings designed by modelling calculations and deposited by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Qi-Chu Zhang [The University of Sydney (Australia). School of Physics; Shen, Y.G. [City University of Hong Kong (Hong Kong). Department of Manufacturing Engineering and Engineering Management

    2004-01-25

    High solar performance W-AIN cermet solar coatings were designed using a numerical computer model and deposited experimentally. In the numerical calculations aluminium oxynitride (AlON) was used as ceramic component. The dielectric functions and then complex refractive index of W-AlON cermet materials were calculated using the Sheng's approximation. The layer thickness and W metal volume fraction were optimised to achieve maximum photo-thermal conversion efficiency for W-AlON cermet solar coatings on an Al reflector with a surface AlON ceramic anti-reflection layer. Optimisation calculations show that the W-AlON cermet solar coatings with two and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimised calculated AlON/W-AlON/Al solar coating film with two cermet layers has a high solar absorptance of 0.953 and a low hemispherical emittance of 0.051 at 80{sup o}C for a concentration factor of 2. The AlN/W-AlN/Al solar selective coatings with two cermet layers were deposited using two metal target direct current magnetron sputtering technology. During the deposition of W-AlN cermet layer, both Al and W targets were run simultaneously in a gas mixture of argon and nitrogen. By substrate rotation a multi-sub-layer system consisting of alternating AlN ceramic and W metallic sub-layers was deposited that can be considered as a macro-homogeneous W-AlN cermet layer. A solar absorptance of 0.955 and nearly normal emittance of 0.056 at 80{sup o}C have been achieved for deposited W-AlN cermet solar coatings. (author)

  7. High performance W-AlN cermet solar coatings designed by modelling calculations and deposited by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qi-Chu [School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Shen, Y.G. [Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong (Hong Kong)

    2004-01-25

    High solar performance W-AlN cermet solar coatings were designed using a numerical computer model and deposited experimentally. In the numerical calculations aluminium oxynitride (AlON) was used as ceramic component. The dielectric function and then complex refractive index of W-AlON cermet materials were calculated using the Sheng's approximation. The layer thickness and W metal volume fraction were optimised to achieve maximum photo-thermal conversion efficiency for W-AlON cermet solar coatings on an Al reflector with a surface AlON ceramic anti-reflection layer. Optimisation calculations show that the W-AlON cermet solar coatings with two and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimised calculated AlON/W-AlON/Al solar coating film with two cermet layers has a high solar absorptance of 0.953 and a low hemispherical emittance of 0.051 at 80C for a concentration factor of 2. The AlN/W-AlN/Al solar selective coatings with two cermet layers were deposited using two metal target direct current magnetron sputtering technology. During the deposition of W-AlN cermet layer, both Al and W targets were run simultaneously in a gas mixture of argon and nitrogen. By substrate rotation a multi-sub-layer system consisting of alternating AlN ceramic and W metallic sub-layers was deposited that can be considered as a macro-homogeneous W-AlN cermet layer. A solar absorptance of 0.955 and nearly normal emittance of 0.056 at 80C have been achieved for deposited W-AlN cermet solar coatings.

  8. Frequency Control Performance Measurement and Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Illian, Howard F.

    2010-12-20

    Frequency control is an essential requirement of reliable electric power system operations. Determination of frequency control depends on frequency measurement and the practices based on these measurements that dictate acceptable frequency management. This report chronicles the evolution of these measurements and practices. As technology progresses from analog to digital for calculation, communication, and control, the technical basis for frequency control measurement and practices to determine acceptable performance continues to improve. Before the introduction of digital computing, practices were determined largely by prior experience. In anticipation of mandatory reliability rules, practices evolved from a focus primarily on commercial and equity issues to an increased focus on reliability. This evolution is expected to continue and place increased requirements for more precise measurements and a stronger scientific basis for future frequency management practices in support of reliability.

  9. Investigation of the role of hydrophilic chain length in amphiphilic perfluoropolyether/poly(ethylene glycol) networks: towards high-performance antifouling coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yapei; Pitet, Louis M.; Finlay, John A.; Brewer, Lenora H.; Cone, Gemma; Betts, Douglas E.; Callow, Maureen E.; Callow, James A.; Wendt, Dean E.; Hillmyer, Marc A.; DeSimone, Joseph M. (Birmingham UK); (NCSU); (UNC); (Cal. Polytech.); (UMM)

    2013-03-07

    The facile preparation of amphiphilic network coatings having a hydrophobic dimethacryloxy-functionalized perfluoropolyether (PFPE-DMA; M{sub w} = 1500 g mol{sup -1}) crosslinked with hydrophilic monomethacryloxy functionalized poly(ethylene glycol) macromonomers (PEG-MA; M{sub w} = 300, 475, 1100 g mol{sup -1}), intended as non-toxic high-performance marine coatings exhibiting antifouling characteristics is demonstrated. The PFPE-DMA was found to be miscible with the PEG-MA. Photo-cured blends of these materials containing 10 wt% of PEG-MA oligomers did not swell significantly in water. PFPE-DMA crosslinked with the highest molecular weight PEG oligomer (ie PEG1100) deterred settlement (attachment) of algal cells and cypris larvae of barnacles compared to a PFPE control coating. Dynamic mechanical analysis of these networks revealed a flexible material. Preferential segregation of the PEG segments at the polymer/air interface resulted in enhanced antifouling performance. The cured amphiphilic PFPE/PEG films showed decreased advancing and receding contact angles with increasing PEG chain length. In particular, the PFPE/PEG1100 network had a much lower advancing contact angle than static contact angle, suggesting that the PEG1100 segments diffuse to the polymer/water interface quickly. The preferential interfacial aggregation of the larger PEG segments enables the coating surface to have a substantially enhanced resistance to settlement of spores of the green seaweed Ulva, cells of the diatom Navicula and cypris larvae of the barnacle Balanu