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Sample records for conversion coating treatment

  1. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  2. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  3. Isomolybdate conversion coatings

    NASA Technical Reports Server (NTRS)

    Minevski, Zoran (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na.sub.2 MoO.sub.4), lithium molybdate (Li.sub.2 MoO.sub.4), potassium molybdate (K.sub.2 MoO.sub.4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight. In addition to the alkali metal molybdates, the conversion coating solution may include alkaline metal passivators selected from lithium nitrate (LiNO.sub.3), sodium nitrate (NaNO.sub.3), ammonia nitrate (NH.sub.4 NO.sub.3), and combinations thereof; lithium chloride, potassium hexafluorozirconate (K.sub.2 ZrF.sub.6) or potassium hexafluorotitanate (K.sub.2 TiF.sub.6).

  4. Microstructure, in vitro corrosion and cytotoxicity of Ca-P coatings on ZK60 magnesium alloy prepared by simple chemical conversion and heat treatment.

    PubMed

    Li, Kaikai; Wang, Bing; Yan, Biao; Lu, Wei

    2013-09-01

    Magnesium alloys are potential biodegradable materials for biomedical application. But their poor corrosion resistance may result in premature failure of implants. In this study, to solve this problem, Ca-P coatings were prepared on ZK60 magnesium alloy by a simple chemical conversion process and heat treatment. Surface characterization showed that a flake-like Dicalcium phosphate dihydrate (DCPD) (CaHPO₄·2H₂O) coating was formed on ZK60 alloy by the chemical conversion process. DCPD transformed into Dicalcium phosphate anhydrous (DCPa) (CaHPO₄) and Ca₂P₂O₇ after heat treatment. Results of potentiodynamic polarization showed the corrosion potential of ZK60 was increased from -1666 mV to -1566 mV with DCPD coating, while -1515 mV was obtained after heat treatment. The corrosion current density of ZK60 was measured to be reduced from 35 µA/cm² to 3.5 µA/cm² with DCPD coating, while a further reduction to 1 µA/cm² was observed after heat treatment. This indicated that the coatings improved the substrate corrosion resistance significantly, and apparently, the heat-treated coating had a higher corrosion resistance. Immersion test demonstrated that both the coatings could provide protection for the substrate and the heat-treated coating could induce deposition of bone-like apatite. Cytotoxicity evaluation revealed that none of the samples induced toxicity to L-929 cells after 1- and 3-day culture. The cytocompatibility of ZK60 was improved by the coatings, with the following sequence: uncoated ZK60 < DCPD-coated ZK60 < heat-treated coating.

  5. An organic chromium-free conversion coating on AZ91D magnesium alloy

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoming; Li, Guangyu; Lian, Jianshe; Jiang, Qing

    2008-12-01

    Traditional conversion coatings on magnesium alloys are usually immersed in a solution containing hexavalent chromium compounds. However, the replacement treatments have been proposed by the present environmental driving to eliminate hexavalent chromium. In this work, a tannic acid based conversion coating on AZ91D magnesium alloy was obtained by treatment in a solution containing tannic acid and ammonium metavanadate. SEM, XPS and IR were used to determine the morphology and structure of the conversion coatings. Continuous and uniform conversion coating was deposited on AZ91D alloy and the main components of the coatings were Al 2O 3, MgF 2 and penta-hydroxy benzamide-magnesium complex. The formation mechanism of the coating was discussed. Polarization measurement and salt spray test showed that the corrosion resistance of the conversion coating was much higher than that of traditional chromate conversion coating.

  6. The effect of surface pre-conditioning treatments on the local composition of Zr-based conversion coatings formed on aluminium alloys

    NASA Astrophysics Data System (ADS)

    Cerezo, J.; Vandendael, I.; Posner, R.; de Wit, J. H. W.; Mol, J. M. C.; Terryn, H.

    2016-03-01

    This study investigates the effect of different alkaline, acidic and thermal pre-conditioning treatments applied to different Al alloy surfaces. The obtained results are compared to the characteristics of Zr-based conversion coatings that were subsequently generated on top of these substrates. Focus is laid on typical elemental distributions on the sample surfaces, in particular on the amount of precipitated functional additives such as Cu species that are present in the substrate matrix as well as in the conversion bath solutions. To this aim, Field Emission Auger Electron spectra, depth profiles and surface maps with superior local resolution were acquired and compared to scanning electron microscopy images of the sample. The results show how de-alloying processes, which occur at and around intermetallic particles in the Al matrix during typical industrial alkaline or acidic cleaning procedures, provide a significant source of crystallization cores for any following coating processes. This is in particular due for Cu-species, as the resulting local Cu structures on the surface strongly affect the film formation and compositions of state-of-the-art Zr-based films. The findings are highly relevant for industrial treatments of aluminium surfaces, especially for those that undergo corrosion protection and painting process steps prior to usage.

  7. A new strategy for improvement of the corrosion resistance of a green cerium conversion coating through thermal treatment procedure before and after application of epoxy coating

    NASA Astrophysics Data System (ADS)

    Mahidashti, Z.; Shahrabi, T.; Ramezanzadeh, B.

    2016-12-01

    The effect of post-heating of CeCC on its surface morphology and chemistry has been studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and contact angle (CA) measurements. The corrosion protection performance of the coatings was investigated by electrochemical impedance spectroscopy (EIS). The effect of thermal treatment of CeCC on the corrosion protection performance of epoxy coating was investigated by EIS. Results showed that the heat treatment of Ce film noticeably improved its corrosion resistance and adhesion properties compared to that of untreated samples. The CeCC deposited on the steel substrate at room temperature had a highly cracked structure, while the amount of micro-cracks significantly reduced after post-heating procedure. Results obtained from EIS analysis confirmed the effect of post-heating of CeCC on its corrosion protection performance enhancement. The increase of post-heating temperature and time up to 140 °C and 3 h led to better results.

  8. Alkaline oxide conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.

    1996-02-01

    Three related conversion coating methods are described that are based on film formation which occurs when aluminum alloys are exposed to alkaline Li salt solutions. Representative examples of the processing methods, resulting coating structure, composition and morphology are presented. The corrosion resistance of these coatings to aerated 0.5 M NaCl solution has been evaluated as a function of total processing time using electrochemical impedance spectroscopy (EIS). This evaluation shows that excellent corrosion resistance can be uniformly achieved using no more than 20 minutes of process time for 6061-T6. Using current methods a minimum of 80 minutes of process time is required to get marginally acceptable corrosion resistance for 2024-T3. Longer processing times are required to achieve uniformly good corrosion resistance.

  9. Developments of chromium-free conversion coatings on galvanized steels

    NASA Astrophysics Data System (ADS)

    Song, Yon-Kyun

    Two kinds of cerium-based conversion coating processes and a moly-phos-silane-silicate coating process were developed for electroplated Zn, electroplated Zn-Ni, hot dip Zn and hot dip Zn-Fe in this project. A reaction type cerium-based conversion coating process for electroplated Zn was optimized using factorial design experiments with the addition of colloidal silica and hydrogen peroxide to a 10mM Ce(NO3)3 solution. In addition an evaporation type cerium-based conversion coating process was evaluated with the addition of silane and a drying treatment. The corrosion loss Q (Cb/cm 2) and protection efficiency P(%) were obtained using a polarization technique and analysis of EIS data. The coating structer was observed using SEM,SAM and XPS. The reaction type cerium-based conversion coating layer was composed of outer Ce3+-OH- complex and the inner Ce 4+-O2--Zn. The corrosion protection provided by the coating layer depends on the chemical states of Ce and O with higher contents of Ce4+ and O2- providing the better corrosion protection. The corrosion resistance and chemical composition of cerium-based conversion coatings on the galvanized steels strongly depends on the chemical state of galvanized steels. A thin Ce-O-Si-Zn and a relatively thick C-Ce-O-Si-Zn complex coating layer was formed on the four different galvanized steels by the reaction and the evaporation type process, respectively. The evaporation type process provided better corrosion protection than the reaction type process. The corrosion ranking of bare(#0) and galvanized steels treated in the reaction type(S1) and evaporation type(S3) was S3>S1>#0 based on the electrochemical data, which agreed with the salt spry testing results. All four galvanized steels treated in the reaction type and evaporation type process passed 24 hrs and 100 hrs, respectively without white rust. The evaporation process for galvanized steels has a high potential to replace the conventional chromate process due to its short

  10. Conversion Coatings for Aluminum Alloys by Chemical Vapor Deposition Mechanisms

    NASA Technical Reports Server (NTRS)

    Reye, John T.; McFadden, Lisa S.; Gatica, Jorge E.; Morales, Wilfredo

    2004-01-01

    With the rise of environmental awareness and the renewed importance of environmentally friendly processes, the United States Environmental Protection Agency has targeted surface pre-treatment processes based on chromates. Indeed, this process has been subject to regulations under the Clean Water Act as well as other environmental initiatives, and there is today a marked movement to phase the process out in the near future. Therefore, there is a clear need for new advances in coating technology that could provide practical options for replacing present industrial practices. Depending on the final application, such coatings might be required to be resistant to corrosion, act as chemically resistant coatings, or both. This research examined a chemical vapor deposition (CVD) mechanism to deposit uniform conversion coatings onto aluminum alloy substrates. Robust protocols based on solutions of aryl phosphate ester and multi-oxide conversion coating (submicron) films were successfully grown onto the aluminum alloy samples. These films were characterized by X-ray Photoelectron Spectroscopy (XPS). Preliminary results indicate the potential of this technology to replace aqueous-based chromate processes.

  11. Non-chromate talc conversion coatings for aluminum

    SciTech Connect

    Buchheit, R.G.; Drewien, C.A.; Finch, J.L.; Stoner, G.E.

    1994-01-01

    A method was developed for applying an inorganic conversion coating on that is procedurally similar to chromate conversion coating methods; this method, however does not use or involve hazardous/toxic chemicals. The coating forms by precipitation involving Al{sup 3+} Li{sup +}, OH{sup {minus}}, CO{sub 3}{sup 2}{minus}, and possibly other anions. This polycrystalline coating is continuous, conformal and persistent in aggressive environments. Coating thicknesses range from several tenths to ten micrometers. Although the outer portions of the coating are porous, the pores do not penetrate to the substrate interface. These coatings do not match the levels of performance offered by commercially available chromate conversion coatings, but are capable of meeting many of the corrosion resistance, electrical resistivity, and paint adhesion requirements established in MIL-C-5541E ``Chemical Conversion Coatings on Aluminum and Aluminum Alloys.`` In this paper, methods for producing the talc coating on aluminum alloys 1100 and 6061-T6 are described and compared to traditional chromate conversion coating methods. Resulting coating structure and composition are described. Performance data for the talc coatings in MIL-C-5541E required tests are presented along with data commercial chromate-based coatings.

  12. Chromate-free corrosion resistant conversion coatings for aluminum

    SciTech Connect

    Buchheit, R.G. ); Stoner, G.E. . Dept. of Materials Science and Engineering)

    1993-01-01

    We have developed a method for generating chromate-free corrosion resistant coatings on aluminum alloys using a process procedurally similar to standard chromate conversion. These coatings provide good corrosion resistance on 6061-T6 and 1100 A1 under salt spray testing conditions. The resistance of the new coating is comparable to that of chromate conversion coatings in four point probe tests, but higher when a mercury probe technique is used. Initial tests of paint adhesion, and under paint corrosion resistance are promising. Primary advantage of this new process is that no hazardous chemicals are used or produced during the coating operation.

  13. Chromate-free corrosion resistant conversion coatings for aluminum

    SciTech Connect

    Buchheit, R.G.; Stoner, G.E.

    1993-03-01

    We have developed a method for generating chromate-free corrosion resistant coatings on aluminum alloys using a process procedurally similar to standard chromate conversion. These coatings provide good corrosion resistance on 6061-T6 and 1100 A1 under salt spray testing conditions. The resistance of the new coating is comparable to that of chromate conversion coatings in four point probe tests, but higher when a mercury probe technique is used. Initial tests of paint adhesion, and under paint corrosion resistance are promising. Primary advantage of this new process is that no hazardous chemicals are used or produced during the coating operation.

  14. Substitute conversion coatings on aluminum for waste minimization

    SciTech Connect

    Buchheit, R.G.; Bode, M.D.; Stoner, G.E.

    1991-09-01

    Chromate conversion coatings such as Parker Company`s Alodine coatings are widely used to increase the corrosion resistance of aluminum and aluminum alloys. The primary disadvantage of chromate-based processes is that they use and produce as waste hexavalent chromium (Cr{sup 6+}). We have discovered that the corrosion resistance of Al can be increased by forming an inorganic barrier coating using chemicals that pose a relatively small environmental hazard. These new coatings are formed using a process that is procedurally identical to the basic chromate conversion process. We have prepared new and conventional coatings on 1100 (99.0 Al minimum), 2024-T3 (Al-Cu-Mg) and 7075-T6 (Al-Zn-Mg) commercial sheet stock for accelerated electrochemical testing and coating conductivity testing. Results show that the new coatings offer increased corrosion resistance compared to uncoated Al, but do not yet match the performance of the chromate conversion coatings. The conductivity of these new films on 1100 Al is comparable to that of Alodine coatings; however, the new coatings are more resistive than Alodine coatings on 2024-T3 and 7075-T6.

  15. Chromate-free talc chemical conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.; Drewien, C.A.; Stoner, G.E.

    1993-10-01

    We have found that aluminum alloys exhibit unusual passivity when exposed to alkaline Li-salt solutions. Observed passivity is due to the formation of a polycrystalline Li{sub 2}[Al{sub 2}(OH){sub 6}]{sub 2}{center_dot}CO{sub 3}{center_dot}3H{sub 2}O film on the aluminum surface. This film is persistent in aggressive environments and provides a significant degree of corrosion protection. On this basis, we have developed a simple non-electrolytic method of forming corrosion resistant coatings in alkaline Li-salt solution. This process is procedurally similar to traditional conversion coating methods, offers desirable properties, and has a low toxic hazard. In this paper, coating methods, coating characterization, and coating properties are presented. Results from parallel test performed with a commercial chromate conversion coatings are presented for comparison.

  16. The effect of cerium-based conversion treatment on the cathodic delamination and corrosion protection performance of carbon steel-fusion-bonded epoxy coating systems

    NASA Astrophysics Data System (ADS)

    Ramezanzadeh, B.; Rostami, M.

    2017-01-01

    The effect of surface pre-treatment of pipe surface by green cerium compound and phosphoric acid solution on the fusion-bonded epoxy (FBE) coating performance was studied. The composition and surface morphology of the steel samples treated by acid and Ce solutions were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), equipped with energy dispersive spectroscopy (EDS). Also, the surface free energy was evaluated on these samples through contact angle measurements. In addition, the effect of Ce and acid washing procedures on the adhesion properties and corrosion protection performance of the FBE was examined by pull-off, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results showed that compared to acid washing, the chemical treatment by Ce solution noticeably increased the surface free energy of steel, improved the adhesion properties of FBE, decreased the cathodic delamination rate of FBE, and enhanced the coating corrosion resistance compared to the acid washed samples.

  17. An alternate to chromate conversion coatings for the corrosion protection of aluminum 2024-T3

    NASA Astrophysics Data System (ADS)

    Guo, Ruiguang

    Corrosion of high-strength aluminum alloys used for airspace application is an expensive and serious problem. The most significant environmental factor contributing to the corrosion of these alloys is water condensed from humid air and contaminated with soluble chloride salts. The Al 2024 series used for aircraft are particularly susceptible to corrosion in aqueous chloride solutions due to alloying constituents such as copper and other impurities. Chromates are efficient inhibitors of corrosion of aluminum in near neutral aqueous environments containing aggressive anions such as chlorides. Usually, aluminum alloys are initially protected by chromate conversion coatings. Additional polymer coatings are sometimes added during exposure to corrosive atmospheres such as marine environments. Although chromate coatings are widely used, they require the use of noxious solutions, so they have always presented effluent disposal problems. There are health and safety concerns over the use of chromates due to their toxicity and carcinogenic nature and, as a consequence, the environmental and health risks associated with the use of such coatings will be restricted in the future. It was these health and safety concerns that led to the development of alternative non-toxic coating processes with comparable adhesion properties and corrosion protection. A variety of process technologies are under development and are vying for acceptance in industrial markets. As an alternate conversion coating, a new titanate conversion coating was systematically researched and developed. Research concentrated on producing passive surfaces from a simple titanate solution using an immersion process. The corrosion resistance of the treated surface has been evaluated using simple, rapid electrochemical techniques as well as a more long-term salt spray test. Passivation by titanate conversion treatment exhibits many similarities to chromate conversion treatment. Based on this study of corrosion

  18. Conversion coatings prepared or treated with calcium hydroxide solutions

    NASA Technical Reports Server (NTRS)

    Minevski, Zoran (Inventor); Clarke, Eric (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%.

  19. Microstructural characteristics of cerium oxide conversion coatings obtained by various aqueous deposition methods

    SciTech Connect

    Johnson, B.Y.; Edington, J.; Williams, A.; O'Keefe, M.J. . E-mail: mjokeefe@umr.edu

    2005-01-15

    Microstructural characteristics of cerium oxide conversion coatings obtained by electrolytic, dip-immersion and spray deposition methods from aqueous solutions were studied by transmission electron microscopy and electron diffraction analysis. The coatings were applied to aluminum alloy 7075-T6 panels and the pretreatment conditions were the same for all coating methods. The results indicated that the as-deposited coatings were all composed of nanocrystalline particles with narrow size distributions. Electron diffraction analysis revealed that the electrolytic and the spray coatings developed the same crystal structure, possibly Ce{sub 7}O{sub 12}, while the dip-immersion coating had a different structure that has not been reported in the literature. After post-treatment in phosphate solution, all three as-deposited coatings were converted to hydrated cerium phosphate.

  20. Trivalent Chromium Conversion Coatings for Aluminum

    DTIC Science & Technology

    1993-09-27

    salts corrosion. This is without any hexavalent chromium in the bath. The absence of Cr+ 6 was determined by analysis of the bath by atomic absorption spectroscopy and...coating was determined by dissolving the films 5 minutes in 25% (vol.) HC1 at 250 C and analyzing for Cr 20 by atomic absorption spectroscopy . The solution

  1. Chemical conversion coating for protecting magnesium alloys from corrosion

    DOEpatents

    Bhargava, Gaurang; Allen, Fred M.; Skandan, Ganesh; Hornish, Peter; Jain, Mohit

    2016-01-05

    A chromate-free, self-healing conversion coating solution for magnesium alloy substrates, composed of 10-20 wt. % Mg(NO.sub.3).sub.2.6H.sub.2O, 1-5 wt. % Al(NO.sub.3).sub.3.9H.sub.2O, and less than 1 wt. % of [V.sub.10O.sub.28].sup.6- or VO.sub.3.sup.- dissolved in water. The corrosion resistance offered by the resulting coating is in several hundreds of hours in salt-spray testing. This prolonged corrosion protection is attributed to the creation of a unique structure and morphology of the conversion coating that serves as a barrier coating with self-healing properties. Hydroxoaluminates form the backbone of the barrier protection offered while the magnesium hydroxide domains facilitate the "slow release" of vanadium compounds as self-healing moieties to defect sites, thus providing active corrosion protection.

  2. Conversion of Oxyfluoride Based Coated Conductors

    SciTech Connect

    Dan Wesolowski

    2006-11-01

    Direct measurements of HF pressure in equilibrium with the film during the BaF2 process are sorely needed. It is the HF partial pressure that governs the rate at which the film composition is changing and is, therefore, an important factor in controlling the composition/time trajectory of the film. Establishing the composition/time trajectory of both MOD-derived and e-beam derived films for a given set of conditions is another goal for the project. These studies will provide a fundamental understanding of the ex situ process for producing coated conductors.

  3. Chromate-free corrosion resistant conversion coatings for aluminum alloys

    SciTech Connect

    Buchheit, R.G.; Drewien, C.A.; Martinez, M.A.; Stoner, G.E.

    1995-03-01

    Inorganic polycrystalline hydrotalcite, Li{sub 2}[Al{sub 2}(OH){sub 6}]{sub 2}{center_dot}CO{sub 3}{center_dot}3H{sub 2}O, coatings can be formed on aluminum and aluminum alloys by exposure to alkaline lithium carbonate solutions. This process is conducted using methods similar to traditional chromate conversion coating procedures, but does not use or produce toxic chemicals. The coating provides anodic protection and delays the onset of pitting during anodic polarization. Cathodic reactions are also inhibited which may also contribute to corrosion protection. Recent studies have shown that corrosion resistance can be increased by sealing hydrotalcite coated surfaces to transition metal salt solutions including Ce(NO{sub 3}){sub 3}, KMnO{sub 4} and Na{sub 2}MoO{sub 4}. Results from these studies are also reported.

  4. Chromate Conversion Coating of Aluminum Alloys

    DTIC Science & Technology

    1975-07-10

    a sodium sulfate-nitric acid solution sometimes used to clean aluminum prior to spotwelding. Immersion times were varied in the chromate-sulfate...Good results were also obtained with sodium sulfate-nitric acid and an 8 minute treatment in one non-chromete proprietary solution. Average resis...molybdate or tungstate salts with the ferricyanide ion considered to be the most effective accelerator. Water for Bath Make-Up and Rinsing It is very

  5. The Corrosion Behaviors of the Cerium Conversion Coatings on the Zinc Coating in a 5 % NaCl Solution

    NASA Astrophysics Data System (ADS)

    Zhang, Jianghong; Meng, Binfang; Wang, Xinying; Li, Wei

    2017-01-01

    The present paper investigated the impact of cerium on the corrosion resistance of zinc coating in a 5 % NaCl solution. Electrochemistry was used to measure the electrochemical parameters to compare the corrosion resistance of the zinc coating with that of the cerium conversion coating on the galvanized layer. SEM/EDS and XRD were adopted to analyze the appearance and phases of corrosion products of the cerium conversion coating and to probe the impact of cerium on the corrosion behavior of zinc coating in the Cl- media. The results showed that the cerium conversion coating formed on the zinc coating increased the zinc's corrosion resistance effectively, conversion coating with lower cerium content protected the substrate poorly, resulting in easy erosion of the zinc coating in the Cl- media. The corrosion products mainly consist of complexes, such as Zn(OH)xCly and Ce(OH)xCly.

  6. Copper Iron Conversion Coating for Solid Oxide Fuel Cell Interconnects

    NASA Astrophysics Data System (ADS)

    Grolig, Jan Gustav; Alnegren, Patrik; Froitzheim, Jan; Svensson, Jan-Erik

    2015-11-01

    A conversion coating of iron and copper was investigated with the purpose of increasing the performance of Sanergy HT as a potential SOFC interconnect material. Samples were exposed to a simulated cathode atmosphere (air, 3 % H2O) for durations of up to 1000 h at 850 °C. Their performance in terms of corrosion, chromium evaporation and electrical resistance (ASR) was monitored and compared to uncoated and cobalt-coated Sanergy HT samples. The copper iron coating had no negative effects on corrosion protection and decreased chromium evaporation by about 80%. An Area Specific Resistance (ASR) of 10 mΩcm2 was reached after 1000 h of exposure. Scanning Electron Microscopy revealed well adherent oxide layers comprised of an inner chromia layer and an outer spinel oxide layer.

  7. Microstructure and corrosion resistance of phytic acid conversion coatings for magnesium alloy

    NASA Astrophysics Data System (ADS)

    Cui, Xiufang; Li, Qingfen; Li, Ying; Wang, Fuhui; Jin, Guo; Ding, Minghui

    2008-12-01

    In this paper, a new innoxious and pollution-free chemical protective coating for magnesium alloys, phytic acid conversion coating, was prepared. The conversion coatings are found to have high cover ratio and no cracks are found by atomic force microscopes (AFM) and scanning electron microscopy (SEM). The main elements of the conversion coatings are Mg, Al, O, P and C by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The chemical state of the elements in the coatings was also investigated by Fourier transform infrared spectroscopy (FTIR). AES depth profile analysis suggests that the thickness of the conversion coating is about 340 nm. The corrosion resistance of the coatings was evaluated by polarization curves. The results indicate that the corrosion resistance for the conversion coated AZ91D magnesium alloys in 3.5% NaCl solution increases markedly. The mechanisms of corrosion resistance and coatings formation are also discussed.

  8. Effects of double encapsulation and coating on synthetic seed conversion in M.26 apple rootstock.

    PubMed

    Micheli, M; Pellegrino, S; Piccioni, E; Standardi, A

    2002-01-01

    Encapsulated vitro-derived apical buds of M.26 apple rootstock (Malus pumila Mill) can be employed for the formation of the synthetic seed. Satisfactory levels of conversion (plantlets from synthetic seed) can be achieved if there are adequate (i) rooting induction treatment, (ii) protocol of encapsulation, and (iii) nutritive and environmental conditions. For capsule manufacturing, sodium alginate is largely used; however, this is excessively permeable with loss of the nutritive substances (artificial endosperm) and/or dehydration risks during conservation and transport causing detrimental effects on the synthetic seed conversion and on the plantlet's growth. In order to overcome these problems, two experiments were carried out comparing simple encapsulation in alginate with double encapsulation, and with encapsulation-coating procedures. The presence of a second layer of alginate (double encapsulation) and of a thin external coating layer over the alginate (encapsulation-coating) did not show any detrimental effects on viability, sprouting and regrowth of the encapsulated microcuttings. Satisfactory conversion (70%) was reached with the encapsulation-coating procedure, whereas the double and simple encapsulation converted less than 40% of the synthetic seed. The effect of the addition to the capsule of an anti-microbial substance (Plant Preservative Mixture - PPM) was examined: it did not compromise the conversion of the encapsulated microcuttings sown in ex-vitro non-aseptic conditions.

  9. Formation of Self-Assembled Monolayer on Cerium Conversion Coated AZ31 Mg Alloy

    NASA Astrophysics Data System (ADS)

    Salman, S. A.; Akira, N.; Kuroda, K.; Okido, M.

    Magnesium alloys are recognized as alternatives to Al alloys and steel to reduce the weight of structural materials. However, a major obstacle to the widespread use of magnesium alloys is its poor corrosion resistance. Therefore, further surface treatment of magnesium and its alloy is important in meeting several industrial specifications. In a previous research, we investigated the surface treatment of AZ31 magnesium alloy using cerium conversion coating. The anticorrosion properties could be improved with the cerium treatment. In this present research, self-assembled monolayer (SAM) was adsorbed on the surface of cerium conversion coated AZ31 magnesium alloy. The SAM thin film was deposited using (Tridecafluoro-1, 1, 2, 2-tetrahydrooctyl) trimethoxysilane (FAS13) and Tetrakis(trimethylsiloxy)titanium (TTMS) as a catalyst. The corrosion resistance of cerium conversion coated AZ31 Mg alloy was improved with SAM post treatment. Furthermore, the contact angle increases from 13 deg. to 169 deg. indicating to production of super hydrophobic surface with SAM post treatment.

  10. Effect of microstructure on the zinc phosphate conversion coatings on magnesium alloy AZ91

    NASA Astrophysics Data System (ADS)

    Van Phuong, Nguyen; Moon, Sungmo; Chang, Doyon; Lee, Kyu Hwan

    2013-01-01

    The effect of the microstructure, particularly of β-Mg17Al12 phase, on the formation and growth of zinc phosphate conversion coatings on magnesium alloy AZ91 (AZ91) was studied. The zinc phosphate coatings were formed on AZ91 with different microstructures produced by heat treatment. The effect of the microstructure on the zinc phosphate coatings were examined using optical microscope (OM), X-ray diffraction (XRD), coatings weight and etching weight balances, scanning electron microscopy (SEM) and salt immersion test. Results showed that as-cast AZ91 contained a high volume fraction of the β-Mg17Al12 phase and it was dissolved into α-Mg phase during heat treatment at 400 °C. The β-phase became center for hydrogen evolution during phosphating reaction (cathodic sites). The decreased volume fraction of the β-phase caused decreasing both coatings weight and etching weight of the phosphating process. However, it increased the crystal size of the coatings and improved corrosion resistance of AZ91 by immersing in 0.5 M NaCl solution. Results also showed that the structure of the zinc phosphate conversion on AZ91 consisted of two layers: an outer crystal Zn3(PO4)2·4H2O (hopeite) and an inner which was mainly composed of MgZn2(PO4)2 and Mg3(PO4)2. A mechanism for the formation of two layers of the coatings was also proposed in this study.

  11. Preparation and properties of chrome-free colored Ti/Zr based conversion coating on aluminum alloy

    NASA Astrophysics Data System (ADS)

    Yi, AiHua; Li, WenFang; Du, Jun; Mu, SongLin

    2012-06-01

    A golden conversion coating on the surface of aluminum alloy was prepared by adding tannic acid and coating-forming accelerator in the treatment solution containing titanium and zirconium ions. The growth process, main component and corrosion resistance of the conversion coating were characterized by EDS, SEM, XRD, XPS, FIIR and electrochemical workstation. The results showed that the main components of the conversion coating were Na3AlF6 and the conversion coating owns a double-layer structure. The outer layer consists of metal-organic complex and the inner layer is mainly made up of Na3AlF6. The mechanism of the formation of the golden conversion coating can be deemed as nucleation, growth of Na3AlF6 crystal and formation of metal-organic complex. In potentiodynamic polarization test, the corrosion current density decreases to 0.283 μA cm-2 from 5.894 μA cm-2, which indicates an obvious improvement of corrosion resistance.

  12. Titanium composite conversion coating formation on CRS In the presence of Mo and Ni ions: Electrochemical and microstructure characterizations

    NASA Astrophysics Data System (ADS)

    Eivaz Mohammadloo, H.; Sarabi, A. A.

    2016-11-01

    There have been an increasing interest in finding a replacement for the chromating process due to environmental and health concerns. Hence, in this study Chrome-free chemical conversion coatings were deposited on the surface of cold-rolled steel (CRS) on the basis of Titanium (TiCC), Titanium-Nickel (TiNiCC) and titanium-molybdate (TiMoCC) based conversion coating solutions. The surface characterization was performed by field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measuring device. Also, the corrosion behavior was assessed by the means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. FESEM and AFM study show that the TiNiCC is denser and more uniform than that TiCC and TiMoCC since, TiMoCC conversion coating presents network feature, and there were abundant micro-cracks on the surface of the coating. XPS results confirmed the precipitation of Ti and Ni oxide/hydroxide, Mn dioxide/trioxide on the surface of different Ti-based conversion coatings. Electrochemical results revealed that all Ti-based conversion coatings have better anti-corrosion properties than bare CRS. Moreover, TiNiCC treatment inhibited the corrosion of CRS to a significant degree (polarization resistance (Rp) = 5510 Ω cm2) in comparison with TiCC (Rp = 2705 Ω cm2) and TiMoCC (Rp = 805 Ω cm2).

  13. Cerium-based conversion coatings on magnesium alloys

    NASA Astrophysics Data System (ADS)

    Castano Londono, Carlos Eduardo

    This research is primarily focused on gaining a better understanding of the deposition and corrosion behavior of cerium-based conversion coatings (CeCCs) on AZ31B and AZ91D Mg alloys. Deposition of homogenous and protective CeCCs was highly dependent on the surface preparation steps. The best results were obtained when Mg samples underwent grinding, acid cleaning, and alkaline cleaning processes. This reduced the number of active cathodic sites and promoted the formation of a protective Al-rich Mg oxide/hydroxide layer. Electrochemical properties of the CeCCs were also strongly correlated with morphological, microstructural, and chemical characteristics. Protective CeCCs were deposited on both AZ31 and AZ91 Mg alloys using a range of deposition times (5 to 180 s) and temperatures (10 to 80 °C). However, shorter deposition times (5 s) and lower deposition temperatures (~10 °C) showed higher impedance and longer bath stability than other deposition conditions. The increase in impedance was related with fewer cracks and smaller nodule sizes. Additional investigations of post-treated CeCCs exposed to NaCl environments showed an increased in the total impedance. The increase in corrosion protection of the CeCCs was associated with an overall increase in coating thickness from 400 to 800 nm. A microstructural evolution from ~3 nm nodular nanocrystals of CeO2/CePO4*H2O embedded in an amorphous matrix to >50 nm CePO4*H2O nanocrystals was responsible for the electrochemically active corrosion protection. Exposure of CeCCs to sunlight in humid environments promoted the reduction of Ce(IV) into Ce(III) species compared to unexposed coatings. This reduction process was related with photocatalytic water oxidation reaction.

  14. Effect of Native Oxide Film on Commercial Magnesium Alloys Substrates and Carbonate Conversion Coating Growth and Corrosion Resistance

    PubMed Central

    Feliu, Sebastián; Samaniego, Alejandro; Bermudez, Elkin Alejandro; El-Hadad, Amir Abdelsami; Llorente, Irene; Galván, Juan Carlos

    2014-01-01

    Possible relations between the native oxide film formed spontaneously on the AZ31 and AZ61 magnesium alloy substrates with different surface finish, the chemistry of the outer surface of the conversion coatings that grows after their subsequent immersion on saturated aqueous NaHCO3 solution treatment and the enhancement of corrosion resistance have been studied. The significant increase in the amount of aluminum and carbonate compounds on the surface of the conversion coating formed on the AZ61 substrate in polished condition seems to improve the corrosion resistance in low chloride ion concentration solutions. In contrast, the conversion coatings formed on the AZ31 substrates in polished condition has little effect on their protective properties compared to the respective as-received surface. PMID:28788582

  15. Processing and properties of chromate-free conversion coatings on aluminum

    SciTech Connect

    Buchheit, R.G.; Drewien, C.A.; Martinez, M.A.; Stoner, G.E.

    1994-12-31

    A conversion coating method has been developed based on precipitation of Li{sub 2}[Al{sub 2}(OH){sub 6}]{sub 2}{center_dot}CO{sub 3}{center_dot}3H{sub 2}O from alkaline lithium salt solutions. The process is procedurally similar to chromate conversion coating but does not use or produce hazardous chemicals. The coating that forms is polycrystalline, continuous and conformal. The coating meets the MIL-C-5541E corrosion resistance, electrical contact resistance and paint adhesion requirements for certain aluminum alloys, but does not match the levels of performance exhibited by chromate conversion coatings. In this paper, methods for producing the coating are described. Corrosion resistance has been characterized using electrochemical impedance spectroscopy and salt spray exposure. The structural, compositional and property changes attending post-coating thermal exposure are discussed. Performance in standardized corrosion, electrical and paint adhesion tests is also presented.

  16. Thermal Spraying Coatings Assisted by Laser Treatment

    NASA Astrophysics Data System (ADS)

    Fenineche, N. E.; Cherigui, M.

    2008-09-01

    Coatings produced by air plasma spraying (APS) are widely used to protect components against abrasive wear and corrosion. However, APS coatings contain porosities and the properties of these coatings may thereby be reduced. To improve these properties, various methods could be proposed, including post-laser irradiation [1-4]. Firstly, PROTAL process (thermal spraying assisted by laser) has been developed as a palliative technique to degreasing and grit-blasting prior to thermal spraying. Secondly, thermal spray coatings are densified and remelted using Laser treatment. In this study, a review of microstructure coatings prepared by laser-assisted air plasma spraying will be presented. Mechanical and magnetic properties will be evaluated in relation to changes in the coating microstructure and the properties of such coatings will be compared with those of as-sprayed APS coatings.

  17. Thermal Spraying Coatings Assisted by Laser Treatment

    SciTech Connect

    Fenineche, N. E.; Cherigui, M.

    2008-09-23

    Coatings produced by air plasma spraying (APS) are widely used to protect components against abrasive wear and corrosion. However, APS coatings contain porosities and the properties of these coatings may thereby be reduced. To improve these properties, various methods could be proposed, including post-laser irradiation [1-4]. Firstly, PROTAL process (thermal spraying assisted by laser) has been developed as a palliative technique to degreasing and grit-blasting prior to thermal spraying. Secondly, thermal spray coatings are densified and remelted using Laser treatment. In this study, a review of microstructure coatings prepared by laser-assisted air plasma spraying will be presented. Mechanical and magnetic properties will be evaluated in relation to changes in the coating microstructure and the properties of such coatings will be compared with those of as-sprayed APS coatings.

  18. Titanium conversion coatings on the aluminum foil AA 8021 used for lithium-ion battery package

    NASA Astrophysics Data System (ADS)

    Xia, Xu-Feng; Gu, Ying-Ying; Xu, Shi-Ai

    2017-10-01

    In this study, an environment-friendly titanium (Ti) conversion coating was successfully deposited on the aluminum foil AA 8021 in the solution containing hexafluorotitanic acid (H2TiF6), and its morphology, composition, growth process, hydrophilicity and corrosion resistance were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray photoelectric spectroscopy (XPS), contact-angle measurements (CAM) and salt spray exposure. The peeling strength between the Ti treated Al foil and the modified polypropylene (PP) film (PP grafted with maleic anhydride, PP-g-MAH) (Al/PP-g-MAH) was measured by T-peeling test. The results show that the Ti conversion coating is a multi-component coating composed primarily of metal oxides (TiO2 and Al2O3) and metal fluoride (AlF3). Ti treated Al foil shows better corrosion resistance than untreated and alkali-cleaned Al foils. The peeling strength of PP-g-MAH film with Ti treated Al foils is approximately 30 times higher than that with untreated Al foils. Thus, Ti treatment is a promising approach to improve the corrosion resistance and peeling strength of aluminum/polymer composite film (Al/P) used in the lithium-ion battery package.

  19. Issues for conversion coating of aluminum alloys with hydrotalcite

    SciTech Connect

    Drewien, C.A.; Buchheit, R.G.

    1993-12-01

    Hydrotalcite coatings on aluminum alloys are being developed for corrosion protection of aluminum in aggressive saline environments. Coating bath composition, surface pretreatment, and alloying elements in aluminum all influence the performance of these coatings during salt spray testing. The coating bath, comprised of lithium carbonate, requires aging by dissolution of aluminum into the bath in order to grow corrosion resistant coatings. Coatings formed in non- aged baths do not perform well in salt spray testing. The alloying elements in aluminum alloys, especially copper, influence the coating growth and formation leading to thin coatings. The effect of the alloy elements is to limit the supply of aluminum to the coating/electrolyte interface and hinder growth of hydrotalcite upon aluminum alloys.

  20. A brief review of calcium phosphate conversion coating on magnesium and its alloys

    NASA Astrophysics Data System (ADS)

    Zaludin, Mohd Amin Farhan; Jamal, Zul Azhar Zahid; Jamaludin, Shamsul Baharin; Derman, Mohd Nazree

    2016-07-01

    Recent developments have shown that magnesium is a promising candidate to be used as a biomaterial. Owing to its light weight, biocompatibility and compressive strength comparable with natural bones makes magnesium as an excellent choice for biomaterial. However, high reactivity and low corrosion resistance properties have restricted the application of magnesium as biomaterials. At the moment, several strategies have been developed to solve this problem. Surface modification of magnesium is one of the popular solutions to solve the problem. Among many techniques developed in the surface modification, conversion coating method is one of the simple and effective techniques. From various types of conversion coating, calcium phosphate-based conversion coating is the most suitable for biomedical fields. This paper reviews some studies on calcium phosphate coating on Mg and its alloys via chemical conversion method and discusses some factors determining the coating performance.

  1. Low emittance chromated chemical conversion coatings for spacecraft thermal control in low earth orbit

    NASA Astrophysics Data System (ADS)

    LeVesque, R. J.; DeJesus, R. R.; Jones, C. A.; Babel, H. W.

    1996-03-01

    Low emittance coatings were required on the inner side of micro-meteoroid shielding and other structures to minimize heat transfer from the sun illuminated side to the underlying structure. A program was undertaken to evaluate conversion coatings for long term use in space. The conversion coatings evaluated were Alodine 1200 with three different bath chemistries, Iridite 14-2, and Alodine 600. Although the primary emphasis was on evaluating how processing conditions influenced the infrared emittance, corrosion resistance and electrical bonding characteristics were also evaluated. All of the conversion coatings were able to provide the target emittance value of less than 0.10, although baths with ferricyanide accelerators required shorter immersion times than typical of standard shop practices. The balance between emittance, corrosion resistance, and electrical bonding were defined. Space environmental stability tests were conducted on conversion coated 2219 and 7075 aluminum. The emittance and the electrical bonding characteristics were not affected by the space exposure even though the coating dehydrated and mud cracking is evident under a microscope. The dehydration resulted in a loss of corrosion resistance which is a consideration for hardware returned to Earth. It was concluded that conversion coatings are acceptable thermal control coatings for long life spacecraft although additional work is recommended for solar exposed surfaces.

  2. Low emittance chromated chemical conversion coatings for spacecraft thermal control in low earth orbit

    SciTech Connect

    LeVesque, R.J. II; DeJesus, R.R.; Jones, C.A.; Babel, H.W.

    1996-03-01

    Low emittance coatings were required on the inner side of micro-meteoroid shielding and other structures to minimize heat transfer from the sun illuminated side to the underlying structure. A program was undertaken to evaluate conversion coatings for long term use in space. The conversion coatings evaluated were Alodine 1200 with three different bath chemistries, Iridite 14-2, and Alodine 600. Although the primary emphasis was on evaluating how processing conditions influenced the infrared emittance, corrosion resistance and electrical bonding characteristics were also evaluated. All of the conversion coatings were able to provide the target emittance value of less than 0.10, although baths with ferricyanide accelerators required shorter immersion times than typical of standard shop practices. The balance between emittance, corrosion resistance, and electrical bonding were defined. Space environmental stability tests were conducted on conversion coated 2219 and 7075 aluminum. The emittance and the electrical bonding characteristics were not affected by the space exposure even though the coating dehydrated and mud cracking is evident under a microscope. The dehydration resulted in a loss of corrosion resistance which is a consideration for hardware returned to Earth. It was concluded that conversion coatings are acceptable thermal control coatings for long life spacecraft although additional work is recommended for solar exposed surfaces. {copyright} {ital 1996 American Institute of Physics.}

  3. Waste treatment for removed protective coatings

    SciTech Connect

    Gat, U.; Crosley, S.M.; Gay, R.L.

    1993-07-01

    A molten salt oxidation process is proposed for treatment of removed protective coatings along with the media used for removal. The treatment chemically reduces the waste, leaving any metals associated with the coating as a residue in the salt treatment media. The residue and the salt can be further treated for recycle of the metals, thus all but eliminating metal disposal as a waste problem. The process is expected to be simple and may be integrated into the coatings removal operations on location. Therefore, waste shipment and handling can be significantly reduced, and, as a secondary benefit, other waste can be treated in the same unit.

  4. Laboratory Validation and Demonstrations of Non-Hexavalent Chromium Conversion Coatings for Steel Substrates (Briefing Charts)

    DTIC Science & Technology

    2011-02-01

    Organo- silane • PPG Zircobond 4200 - Non-chrome Zirconium-based steel conversion coating Baseline Steel Pretreatments: • PPG Cheminhib 420 - Flash rust...Cracking: • Rising Step Load – ASTM F 1624-95 Chip Resistance: • Gravelometer – SAE-J400 Accelerated Corrosion Chamber Rising Step Load Paint Adhesion...Carbon Steel Laboratory Validation Results Chip Resistance SAE-400J Gravelometer Alternative conversion coatings demonstrate better-than or equal-to

  5. The Corrosion Resistance and Paint Adhesion Properties of Chromate Conversion Coatings on Aluminium and Its Alloys

    DTIC Science & Technology

    1976-05-01

    aluminium and its alloys has been evaluated with respect to both corrosion resistance of, and paint adhesion to, the chromate films. The process involves...The findings in this Report will be used as the basis for a Defence Standard for chromate conversion coatings for aluminium and aluminium alloys...3 PROPRIETARY CHROMATE CONVERSION COATINGS FOR ALUMINIUM 17 4 PAINT ADHESION 19 5 DISCUSSION 21 6 CONCLUSIONS 24 Acknowledgments 25 Appendix A

  6. Remanufacture of Zirconium-Based Conversion Coatings on the Surface of Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Liu, Zhe; Jin, Guo; Song, Jiahui; Cui, Xiufang; Cai, Zhaobing

    2017-04-01

    Brush plating provides an effective method for creating a coating on substrates of various shapes. A corroded zirconium-based conversion coating was removed from the surface of a magnesium alloy and then replaced with new coatings prepared via brush plating. The structure and composition of the remanufactured coating were determined via x-ray photoelectron spectroscopy, x-ray diffraction, and Fourier transform infrared spectroscopy. The results revealed that the coatings consist of oxide, fluoride, and tannin-related organics. The composition of the coatings varied with the voltage. Furthermore, as revealed via potentiodynamic polarization spectroscopy, these coatings yielded a significant increase in the corrosion resistance of the magnesium alloy. The friction coefficient remained constant for almost 300s during wear resistance measurements performed under a 1-N load and dry sliding conditions, indicating that the remanufactured coatings provide effective inhibition to corrosion.

  7. Remanufacture of Zirconium-Based Conversion Coatings on the Surface of Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Liu, Zhe; Jin, Guo; Song, Jiahui; Cui, Xiufang; Cai, Zhaobing

    2017-03-01

    Brush plating provides an effective method for creating a coating on substrates of various shapes. A corroded zirconium-based conversion coating was removed from the surface of a magnesium alloy and then replaced with new coatings prepared via brush plating. The structure and composition of the remanufactured coating were determined via x-ray photoelectron spectroscopy, x-ray diffraction, and Fourier transform infrared spectroscopy. The results revealed that the coatings consist of oxide, fluoride, and tannin-related organics. The composition of the coatings varied with the voltage. Furthermore, as revealed via potentiodynamic polarization spectroscopy, these coatings yielded a significant increase in the corrosion resistance of the magnesium alloy. The friction coefficient remained constant for almost 300s during wear resistance measurements performed under a 1-N load and dry sliding conditions, indicating that the remanufactured coatings provide effective inhibition to corrosion.

  8. Synthesis and Characterization of Chromate Conversion Coatings on GALVALUME and Galvanized Steel Substrates

    NASA Astrophysics Data System (ADS)

    Domínguez-Crespo, M. A.; Onofre-Bustamante, E.; Torres-Huerta, A. M.; Rodríguez-Gómez, F. J.; Rodil, S. E.; Flores-Vela, A.

    2009-07-01

    The morphology, composition, and corrosion performance of chromate conversion coatings (CCCs) formed on GALVALUME (Fe-Al-Zn) and galvanized steel (Fe-Zn) samples have been studied, and different immersion times (0, 10, 30, and 60 seconds) have been compared. The coated surfaces were analyzed using light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements in a NaCl solution (3 wt pct). The electrochemical measurements were carried out using the polarization resistance, Tafel, and ac impedance methods. A nonuniform growth of the CCCs having a porous morphology and cracks that appear extended to the base metal was observed. The XRD patterns show that the coatings mainly consist of CrO3, Cr2O3, and traces of Cr2O{7/-2}. The electrochemical results show that GALVALUME presents a better behavior than that of the galvanized steel alloys at each dipping time. The SEM micrographs show that the galvanized steel treatments resulted in the formation of a more uniform film, but their protection barrier broke down faster than that of the GALVALUME samples in contact with the aggressive media. The samples that underwent the lowest degree of dissolution were those with a dipping time of 30 seconds. The difference in the corrosion protection given by the two substrate types could be attributed to the structural properties, grain size, composition, and roughness, which affect oxygen diffusion.

  9. Corrosion protection comparison of a chromate conversion coating to a novel conductive polymer coating on aluminum alloys

    SciTech Connect

    Racicot, R.J.; Yang, S.C.; Brown, R.

    1997-12-01

    Comparisons of the corrosion resistance performance of a novel polyaniline based double strand conductive polymer coating versus a chromate conversion coating on two aluminum alloys were made. Potentiodynamic scans, electrochemical impedance spectroscopy (EIS) in 0.5N NaCl solutions and ASTM B-117 salt spray tests were performed on coated samples of AA7075-T6 and AA2024-T3 aluminum alloys. Results show the conductive polymer film offers, at the least, an equivalent protection performance as the chromate coating with a two order of magnitude reduction in corrosion current densities in cyclic polarization tests, near equivalent impedance values and less undercutting of a scribed area in salt spray test samples. In an acidic salt solution of pH 3.6, the conductive polymer offers an improved performance with a one order of magnitude higher impedance over the chromate coatings.

  10. Microstructure and electrochemical behavior of cerium conversion coating modified with silane agent on magnesium substrates

    NASA Astrophysics Data System (ADS)

    Lei, Li; Shi, Jing; Wang, Xin; Liu, Dan; Xu, Haigang

    2016-07-01

    The cerium conversion coating with and without different concentrations of silane agent bis-(γ-triethoxysilylpropyl)-tetrasulfide (BTESPT) modification is obtained on magnesium alloys. Detailed properties of the coatings and the role of BTESPT as an additive are studied and followed with careful discussion. The coating morphology, wettability, chemical composition and corrosion resistance are characterized by scanning electronic microscope (SEM), water contact-angle, X-ray photoelectron spectroscopy (XPS), potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of the coatings is investigated using EIS. The results indicate that the coating morphology and composition can be controlled by changing silane concentration. The combination of cerium ions and silane molecules could promote the formation of more homogenous and higher hydrophobic coating. The coating turns to be more compact and the adhesive strength between the coating and the magnesium substrate are strongly improved with the formation of Sisbnd Osbnd Si and Sisbnd Osbnd M chemical bonds. The optimum corrosion resistance of the coating in the corrosive media is obtained by 25 ml L-1 BTESPT modification. This whole study implies that the cerium conversion coating modified with certain silane agent deserves cautiousness before its application for corrosion resistance.

  11. An Integrated System for the Treatment of Coal Conversion Wastewater

    SciTech Connect

    Henry Y. Wang; Keeran R. Srinivasan

    1999-02-25

    Treatment of mixed waste from coal conversion wastewaters involves the degradation of toxic organics and the removal of heavy metals. An integrated and cost-effective treatment scheme that can implement such a process is considered essential to promote continued development and growth of coal conversion processes without any deleterious effects on our ecosystem. We have recently developed a pH-dependent, reversible heavy metal adsorption/desorption process which promises to be a cost-effective alternative to the treatment and disposal options currently in place for these inorganic contaminants. Our work shows that: (1) Polydisperse, industrial-grade surfactants can be used in the development of novel, surfactant-coated smectitic clays containing up to 50% by weight of adsorbed surfactant, (2) Reversible adsorption and resorption of cationic (CU(II) and Cd(II)) and anionic (Cr(VI)) heavy metals from their respective aqueous solutions onto these surfactant-modified smectites can be effected using pH of the medium as a switch, and (3) These surfactant-modified smectites can be repeatedly used (up to 5 times) with only a minimal loss in their adsorption potency and with very little leaching of the adsorbed surfactants.

  12. Chemical nature of phytic acid conversion coating on AZ61 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Pan, Fusheng; Yang, Xu; Zhang, Dingfei

    2009-07-01

    Phytic acid (PA) conversion coating on AZ61 magnesium alloy was prepared by the method of deposition. The influences of pH, time and PA concentration on the formation process, microstructure and properties of the conversion coating were investigated. Scanning electron microscopy (SEM) was used to observe the microstructure. The chemical nature of conversion coating was investigated by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) techniques. The corrosion resistance was examined by means of potentiodynamic polarization method. The adhesive ability was tested by score experiments. The results showed that the growth and microstructure of the conversion coatings were all obviously affected by pH, time and PA concentration. In 0.5 mg/ml PA solution with a pH of 5, an optimization conversion coating formed after 20 min immersion time by deposition of PA on AZ61 magnesium alloy surface through chelating with Al 3+. It made the corrosion potential Ecorr of sample shifted positively about 171 mV than that of the untreated sample, and the adhesive ability reached to Grade 1 (in accordance with GB/T 9286).

  13. Characterization of Molybdate Conversion Coatings for Aluminum Alloys by Electrochemical Impedance Spectroscopy

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina

    2000-01-01

    Electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion inhibiting properties of newly developed proprietary molybdate conversion coatings on aluminum alloy 2024-T3 under immersion in aerated 5% (w/w) NaCl. Corrosion potential and EIS measurements were gathered for six formulations of the coating at several immersion times for two weeks. Nyquist as well as Bode plots of the data were obtained. The conversion-coated alloy panels showed an increase in the corrosion potential during the first 24 hours of immersion that later subsided and approached a steady value. Corrosion potential measurements indicated that formulations A, D, and F exhibit a protective effect on aluminum 2024-T3. The EIS spectra of the conversion-coated alloy were characterized by an impedance that is higher than the impedance of the bare alloy at all the immersion times. The low frequency impedance, Z(sub lf) (determined from the value at 0.05 Hz) for the conversion-coated alloy was higher at all the immersion times than that of the bare panel. This indicates improvement of corrosion resistance with addition of the molybdate conversion coating. Scanning electron microscopy (SEM) revealed the presence of cracks in the coating and the presence of cubic crystals believed to be calcium carbonate. Energy dispersive spectroscopy (EDS) of the test panels revealed the presence of high levels of aluminum, oxygen, and calcium but did not detect the presence of molybdenum on the test panels. X-ray photoelectron spectroscopy (XPS) indicated the presence of less than 0.01 atomic percent molybdenum on the surface of the coating.

  14. Chemical composition, electrochemical, and morphological properties of iron phosphate conversion coatings

    SciTech Connect

    Warburton, Y.J.; Gibbon, D.L.; Jackson, K.M.; Gate, L.F.; Rodnyansky, A.; Warburton, P.R.

    1999-09-01

    Iron phosphate conversion coatings are used widely in the pretreatment industry to enhance paint adherence to metal substrates and therefore improve corrosion resistance. However, very limited nonproprietary literature describing the properties of iron phosphate coating is available, as compared to volumes dedicated to zinc phosphate coating. The present study described chemical, electrochemical, and morphological characterizations of iron phosphate coating using x-ray photoelectron spectroscopy (XPS), potentiodynamic scans, and scanning electron microscopy (SEM). For the samples under investigation, the mode of operation of iron phosphate coating was to promote paint adhesion, and the coating itself did not impart significant corrosion protection to the metal substrate. It also was shown that the Fe/P ratio in the phosphate coating ranged from 1:2 to 1:1. When tested in pH 7 buffered phosphate solution, the phosphate coating displayed a passivation region, which also possessed the highest impedance value. The phosphate coating was found to comprise two layers: a dense, adherent layer and a loose, granular top layer. For samples with coating weights of 20 mg/ft{sup 2} to 30 mg/ft{sup 2} (0.22 g/m{sup 2} to 0.32 g/m{sup 2}), the corresponding coating thickness was {approximately} 0.1 {micro}m to 0.3 {micro}m.

  15. Treatment and reuse of coal conversion wastewaters

    SciTech Connect

    Luthy, R. G.

    1980-01-01

    This paper presents a synopsis of recent experimental activities to evaluate processing characteristics of coal conversion wastewaters. Treatment studies have been performed with high-BTU coal gasification process quench waters to assess enhanced removal of organic compounds via powdered activated carbon-activated sludge treatment, and to evaluate a coal gasification wastewater treatment train comprised of sequential processing by ammonia removal, biological oxidation, lime-soda softening, granular activated carbon adsorption, and reverse osmosis. In addition, treatment studies are in progress to evaluate solvent extraction of gasification process wastewater to recover phenolics and to reduce wastewater loading of priority organic pollutants. Biological oxidation of coal gasification wastewater has shown excellent removal efficiencies of major and trace organic contaminants at moderate loadings, addition of powdered activated carbon provides lower effluent COD and color. Gasification process wastewater treated through biological oxidation, lime-soda softening and activated carbon adsorption appears suitable for reuse as cooling tower make-up water. Solvent extraction is an effective means to reduce organic loadings to downstream processing units. In addition, preliminary results have shown that solvent extraction removes chromatographable organic contaminants to low levels.

  16. Coatings and Surface Treatments for Reusable Entry Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Sylvia M.

    2016-01-01

    This talk outlines work in coatings for TPS done at NASA Ames. coatings and surface treatments on reusable TPS are critical for controlling the behavior of the materials. coatings discussed include RCG, TUFI and HETC. TUFROc is also discussed.

  17. Friction Modifier Using Adherent Metallic Multilayered or Mixed Element Layer Conversion Coatings

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor); Defalco, Francis G. (Inventor); Starks, Lloyd L., Sr. (Inventor)

    2013-01-01

    A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, and one or more non-alkaline metals and/or one or more metalloids. The process comprises forming an aqueous solution of water, phosphoric acid or sulfuric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals and/or one or more metalloids. The aqueous solution forms an anti-friction multilayer conversion and/or mixed element coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly without the use of applied external electromotive force, or as an additive in lubricating fluids.

  18. Friction modifier using adherent metallic multilayered or mixed element layer conversion coatings

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor); Defalco, Frank G. (Inventor); Starks, Sr., Lloyd L. (Inventor)

    2012-01-01

    A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, silicon, and one or more non-alkaline metals. The process comprises forming a first aqueous solution of silicate, potassium hydroxide, and ammonium hydroxide; forming a second aqueous solution of water, phosphoric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals, and then combining the first solution with the second solution to form a final solution. This final solution forms an anti-friction multi-layer conversion coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly or as an additive in lubricating fluids.

  19. Comparative study on Ti/Zr/V and chromate conversion treated aluminum alloys: Anti-corrosion performance and epoxy coating adhesion properties

    NASA Astrophysics Data System (ADS)

    Zhu, Wen; Li, Wenfang; Mu, Songlin; Fu, Nianqing; Liao, Zhongmiao

    2017-05-01

    In this study, a Ti/Zr/V conversion coating (TZVCC) was deposited on the surface of aluminum alloy 6063 (AA6063) as an alternative of the chromate conversion coating (CCC). Both the TZVCC treated AA6063 (TZVCC/AA6063) and CCC treated AA6063 (CCC/AA6063) were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and contact angle measuring device. The anti-corrosion performance of the TZVCC/AA6063 and CCC/AA6063 was evaluated by electrochemical measurements and neutral salt spray tests. It showed that both the surface roughness and surface free energy of the AA6063 were significantly increased after TZVCC treatment. The anti-corrosion performance of TZVCC/AA6063 was superior to that of CCC/AA6063. In addition, the effects of the TZVCC and CCC on the adhesion properties and anti-corrosion performance of epoxy coating applied on samples were examined by pull-off tests and electrochemical impedance spectroscopy (EIS). The dry, wet and recovery adhesive strengths of the epoxy coating on TZVCC treated samples (epoxy coated TZVCC/AA6063) were very close to those of epoxy coating on CCC treated ones (epoxy coated CCC/AA6063). The epoxy coated TZVCC/AA6063 showed better corrosion resistance than the epoxy coated CCC/AA6063 and epoxy coated AA6063.

  20. Protection of 2024-T3 aluminium alloy by corrosion resistant phytic acid conversion coating

    NASA Astrophysics Data System (ADS)

    Shi, Hongwei; Han, En-Hou; Liu, Fuchun; Kallip, Silvar

    2013-09-01

    The corrosion protection properties of environmentally friendly phytic acid conversion coatings were studied on 2024-T3 aluminium alloy. The films were prepared under acidic conditions with various pH values and characterised by SEM, EDS, ATR-FTIR and electrochemical techniques. The results indicate that the conversion coatings obtained by immersing the alloy in phytic acid solutions at pH from 3 to 5.5 provide excellent corrosion resistance. ATR-FTIR confirms that the film is formed by deposition of reaction products between Al3+ and phosphate groups in phytic acid molecules. The conformation models of the deposition film are proposed.

  1. A Black Phosphate Conversion Coating on Steel Surface Using Antimony(III)-Tartrate as an Additive

    NASA Astrophysics Data System (ADS)

    Li, Feng; Wang, Guiping

    2016-05-01

    A novel black phosphate conversion coating was formed on steel surface through a Zn-Mn phosphating bath containing mainly ZnO, H3PO4, Mn(H2PO4)2, and Ca(NO3)2, where antimony(III)-tartrate was used as the blackening agent of phosphatization. The surface morphology and composition of the coating were characterized by scanning electron microscopy, energy dispersion spectroscopy, and x-ray photoelectron spectroscopy. Corrosion resistance of the coating was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy. The pH value of the solution had significant influence on the formation and corrosion resistance of the coating. The experimental results indicated that the Sb plays a vital role in the blackening of phosphate conversion coating. The optimal concentration of antimony(III)-tartrate in the phosphating bath used in this experiment was 1.0 g L-1, as higher values reduced the corrosion resistance of the coating. In addition, by saponification and oil seals, the corrosion duration of the black phosphate coating in a copper sulfate spot test can be as long as 20 min.

  2. Controlling initial biodegradation of magnesium by a biocompatible strontium phosphate conversion coating.

    PubMed

    Chen, X B; Nisbet, D R; Li, R W; Smith, P N; Abbott, T B; Easton, M A; Zhang, D-H; Birbilis, N

    2014-03-01

    A simple strontium phosphate (SrP) conversion coating process was developed to protect magnesium (Mg) from the initial degradation post-implantation. The coating morphology, deposition rate and resultant phases are all dependent on the processing temperature, which determines the protective ability for Mg in minimum essential medium (MEM). Coatings produced at 80 °C are primarily made up of strontium apatite (SrAp) with a granular surface, a high degree of crystallinity and the highest protective ability, which arises from retarding anodic dissolution of Mg in MEM. Following 14 days' immersion in MEM, the SrAp coating maintained its integrity with only a small fraction of the surface corroded. The post-degradation effect of uncoated Mg and Mg coated at 40 and 80 °C on the proliferation and differentiation of human mesenchymal stem cells was also studied, revealing that the SrP coatings are biocompatible and permit proliferation to a level similar to that of pure Mg. The present study suggests that the SrP conversion coating is a promising option for controlling the early rapid degradation rate, and hence hydrogen gas evolution, of Mg implants without adverse effects on surrounding cells and tissues.

  3. Facilitating conversation through self-initiated augmentative communication treatment.

    PubMed Central

    Dattilo, J; Camarata, S

    1991-01-01

    We examined the conversational skills of 2 adult males with severe motor and speech deficits resulting from cerebral palsy. A multiple baseline design across subjects was used to determine the effectiveness of an intervention strategy designed to teach them to use an augmentative communication system (Touch Talker) independently. The dependent measure was the number of conversation initiations relative to conversation reactions during spontaneous communication across baseline and treatment. The treatment included specific training on using the augmentative system to participate in communication. Once the intervention began, the production of conversation initiations accelerated at a rapid rate. The treatment program was effective in training the subjects to use the augmentative system to increase conversation participation. These results demonstrate that training on the operation of the device alone is not sufficient to ensure improvement in conversation performance, and that it is important to incorporate direct conversational treatment when providing instruction on the use of augmentative communication systems for severely speech-impaired individuals. PMID:1890052

  4. A chrome-free conversion coating and sealant for aluminum and its alloys

    SciTech Connect

    Bibber, J.W.

    1999-07-01

    For over fifty years, chromates have been the standard against which other conversion coatings and/or sealants have been judged. Due to current environmental and safety concerns, they are being removed from use. This paper presents neutral salt-spray, filiform primer adhesion and electrical conductivity data on a commercial chromate-free, inorganic and non-toxic conversion coating used with a new and unique sealing emulsion. The seal is an organic water based emulsion which when dried on a permanganate based conversion coated aluminum surface will be polymerized, or cured, when heated to 250--300 F for 20 seconds or longer. The higher the temperature, or period of time, the greater the degree of polymerization. The polymerized film is as electrically conductive as chromate films and easily accepts and bonds to applied primers. For in-service repair a conventional heat-gun maybe used. For large surfaces, any other conventional heat source may be used. The 6061-T6, 7075-T6, and 2024-T3 series wrought alloys were tested and directly compared to current chromate based conversion coatings. The tests showed equivalent or superior results in all cases.

  5. Corrosion prevention of magnesium surfaces via surface conversion treatments using ionic liquids

    DOEpatents

    Qu, Jun; Luo, Huimin

    2016-09-06

    A method for conversion coating a magnesium-containing surface, the method comprising contacting the magnesium-containing surface with an ionic liquid compound under conditions that result in decomposition of the ionic liquid compound to produce a conversion coated magnesium-containing surface having a substantially improved corrosion resistance relative to the magnesium-containing surface before said conversion coating. Also described are the resulting conversion-coated magnesium-containing surface, as well as mechanical components and devices containing the conversion-coated magnesium-containing surface.

  6. The surface and electrochemical analysis of permanganate based conversion coating on alclad and unclad 2024 alloy

    NASA Astrophysics Data System (ADS)

    Yoganandan, G.; Balaraju, J. N.; William Grips, V. K.

    2012-09-01

    In the present investigation permanganate based conversion coating (PCC) was developed on AA 2024 alloy using alkaline bath containing Mn/Mo oxyanions. Conversion coating was formed on alclad (APCC) and unclad (UPCC) aluminium alloys by simple immersion method. Surface morphology of the APCC and UPCC specimens exhibited smooth and mud-crack patterns respectively. Elemental analysis showed the presence of higher amounts of Mn (5-6 wt.%) and Mo (0.3 wt.%) on UPCC. Raman and XPS analysis showed the presence of compounds such as MnOx (Mn3O4 and Mn2O3), MnO2, KMnO4, MoOx, MoO2, MoO3/polymolybdate on both coating surfaces. The corrosion current density (icorr) values obtained for both coated surfaces were less than 1 μA/cm2. However, APCC specimen showed the lowest icorr value of about 0.05 μA/cm2 after 168 h of immersion in 3.5% NaCl. EIS studies revealed the higher charge transfer resistance (Rct) values for APCC specimen after 1 and 168 h immersion compared to UPCC. Coated specimens were also tested by continuous salt spray exposure (ASTM B117) with and without cross-hatch mark ('X') for about 750 h. Coating discoloration along with the presence of few corrosion products had been noticed on UPCC specimen after continuous salt spray exposure.

  7. Thick sputtered tantalum coatings for high-temperature energy conversion applications

    SciTech Connect

    Stelmakh, Veronika Peykov, Daniel; Chan, Walker R.; Senkevich, Jay J.; Joannopoulos, John D.; Soljačić, Marin; Celanovic, Ivan; Castillo, Robert; Coulter, Kent; Wei, Ronghua

    2015-11-15

    Thick sputtered tantalum (Ta) coatings on polished Inconel were investigated as a potential replacement for bulk refractory metal substrates used for high-temperature emitters and absorbers in thermophotovoltaic energy conversion applications. In these applications, high-temperature stability and high reflectance of the surface in the infrared wavelength range are critical in order to sustain operational temperatures and reduce losses due to waste heat. The reflectance of the coatings (8 and 30 μm) was characterized with a conformal protective hafnia layer as-deposited and after one hour anneals at 700, 900, and 1100 °C. To further understand the high-temperature performance of the coatings, the microstructural evolution was investigated as a function of annealing temperature. X-ray diffraction was used to analyze the texture and residual stress in the coatings at four reflections (220, 310, 222, and 321), as-deposited and after anneal. No significant changes in roughness, reflectance, or stress were observed. No delamination or cracking occurred, even after annealing the coatings at 1100 °C. Overall, the results of this study suggest that the thick Ta coatings are a promising alternative to bulk substrates and pave the way for a relatively low-cost and easily integrated platform for nanostructured devices in high-temperature energy conversion applications.

  8. Preparation of micro/nano-fibrous brushite coating on titanium via chemical conversion for biomedical applications

    NASA Astrophysics Data System (ADS)

    Liu, Bing; Guo, Yong-yuan; Xiao, Gui-yong; Lu, Yu-peng

    2017-03-01

    Calcium phosphate coatings have been applied on the surface of Ti implants to realize better osseointegration. The formation of dicalcium phosphate dihydrate (CaHPO4·2H2O), mineralogically named brushite on pure Ti substrate has been investigated via chemical conversion method. Coating composition and microstructure have been investigated by X-ray diffractometer, Fourier transform infrared spectrometer and field emission scanning electron microscope. The results reveal that the coatings are composed of high crystalline brushite with minor scholzite (CaZn2(PO4)2·2H2O). A micro/nano-scaled fibrous morphology can be produced in the acidic chemical conversion bath with pH 5.00. The surface of the fibrous brushite coating exhibits high hydrophilicity and corrosion resistance in the simulated body fluid. The osteoblast cells grow and spread actively on the coated samples and the proliferation numbers and alkaline phosphate activities of the cells improve significantly compared to the uncoated Ti. It is suggested that the micro/nano-fibrous brushite coating can be a potential approach to improve the osteoinductivity and osteoconductivity of Ti implant, due to its similarity in morphology and dimension to inorganic components of biological hard tissues, and favorable responses to the osteoblasts.

  9. Design concepts for stable AR coatings on UV frequency conversion crystals

    NASA Astrophysics Data System (ADS)

    Jensen, Lars; Mrohs, Marius; Günster, Stefan; Ristau, Detlev

    2014-10-01

    In an effort to develop next generation UV frequency conversion systems, several steps have to be considered. One aspect crucial for the final conversion stage is a durable coating which shows high resistance for all incident wavelengths. In the regular case, two wavelengths are involved in the generation of the fourth harmonic of the Nd:YAG laser. For a conversion process involving the wavelengths 532nm and 266nm, model AR-coating designs have been developed and tested including SiO2, Al2O3, and HfO2 deposited in an IBS process. During the testing, procedures have been applied that involve both wavelengths at the same time. As in the application, the exit surface is exposed to visible and UV laser radiation, a qualifying test needs to account for these conditions as well.

  10. Thermal Stability and Aging Characteristics of Chromate Conversion Coatings on Aluminum Alloy 2024-T3

    SciTech Connect

    Laget, V.; Jeffcoate, C.; Isaacs, H. S.; Buchheit, R. G.

    1999-10-17

    XANES and electrochemical impedance spectroscopes were used in parallel to correlate the amount of Cr(VI) in chromate conversion coatings (CCC) on Al 2024 and their corrosion resistance in order to understand the degradation mechanisms upon aging or heating. Cr(VI) species appear to be immobilized for temperatures higher than 80 C due to dehydration. CCC are shown to be dynamic in the first month of aging with no significant dehydration. Another degradation mechanism involving chemical changes is to be considered.

  11. Carbon nanotube/polymer composite coated tapered fiber for four wave mixing based wavelength conversion.

    PubMed

    Xu, Bo; Omura, Mika; Takiguchi, Masato; Martinez, Amos; Ishigure, Takaaki; Yamashita, Shinji; Kuga, Takahiro

    2013-02-11

    In this paper, we demonstrate a nonlinear optical device based on a fiber taper coated with a carbon nanotube (CNT)/polymer composite. Using this device, four wave mixing (FWM) based wavelength conversion of 10 Gb/s Non-return-to-zero signal is achieved. In addition, we investigate wavelength tuning, two photon absorption and estimate the effective nonlinear coefficient of the CNTs embedded in the tapered fiber to be 1816.8 W(-1)km(-1).

  12. Fabrication of silica-coated gold nanorods and investigation of their property of photothermal conversion.

    PubMed

    Inose, Tomoya; Oikawa, Takahiro; Shibuya, Kyosuke; Tokunaga, Masayuki; Hatoyama, Keiichiro; Nakashima, Kouichi; Kamei, Takashi; Gonda, Kohsuke; Kobayashi, Yoshio

    2017-03-04

    This study described the preparation of silica-coated Au nanorods (AuNR/SiO2) in a colloidal solution, assessed their property of photothermal conversion, and investigated their ability to kill cancer cells using photothermal conversion. Au-seed nanoparticles were produced by reducing hydrogen tetrachloroaurate (HAuCl4) with sodium borohydride (NaBH4) in aqueous n-hexadecyltrimethylammonium bromide (CTAB) solution. AuNRs were then fabricated by reducing HAuCl4 and silver nitrate (AgNO3) with l-ascorbic acid in the aqueous CTAB solution in the presence of Au-seed nanoparticles. The as-prepared AuNRs were washed by a process composed mainly of centrifugation to remove the CTAB. The washed AuNRs were coated with silica by mixing the AuNR colloidal solution, an aqueous solution of (3-aminopropyl)trimethoxysilane, and tetraethylorthosilicate/ethanol solution with a water/ethanol solution. We found that the addition of AuNR/SiO2 in water, in mice, and in a culture medium with cancer cells, followed by irradiation with a laser, cause an increase in temperature, demonstrating that AuNR/SiO2 have the ability of photothermal conversion. In addition, the cancer cells in the culture medium were found to be killed due to the increase in temperature caused by the photothermal conversion.

  13. Reversible wettability conversion of electrodeposited graphene oxide/titania nanocomposite coating: Investigation of surface structures

    NASA Astrophysics Data System (ADS)

    Naghdi, Samira; Jaleh, Babak; Shahbazi, Nima

    2016-04-01

    Graphene oxide/titania (GO/TiO2) nanocomposite have been successfully prepared by a simple method and deposited on the surface of aluminum (Al) by the electrophoretic deposition method. The effect of thermal annealing on wettability of GO/TiO2 coating has been investigated. According to the obtained results, the water contact angle (WCA) increased with an increase in annealing temperature which may be attributed to the regulation of coating from superhydrophilic (WCA ≈ 5°) to superhydrophobic (WCA ≈ 148°) via thermal annealing. Moreover, the superhydrophobic coating was changed to a superhydrophilic one by using ultraviolet irradiation and this effect was reversible by heat treatment.

  14. A correlation between EIS and salt spray proof tests for the corrosion resistance of conversion coated aluminum alloys

    SciTech Connect

    Buchheit, R.G.; Martinez, M.A.; Cunningham, M.; Jensen, H.; Kendig, M.W.

    1996-09-01

    In this study, 33 different conversion coatings were applied to 5 different Al alloy substrates. Salt spray exposure testing and EIS (electrochemical impedance spectroscopy) were conducted for comparison. A relation was developed.

  15. Carbon-coated Zinc Sulfide nano-clusters: synthesis, photothermal conversion and adsorption properties.

    PubMed

    Bao, Chunlin; Zhu, Guoxing; Shen, Mengqi; Yang, Jing

    2014-12-15

    Carbon-coated cluster-like ZnS nanospheres were synthesized by a facile solvothermal route. ZnCl2, thiourea, and glucose were selected as the raw materials. The formed ZnS with hexagonal phase has spherical cluster-like structure, which shows good monodispersity in size. A thin layer carbon is coated on the surface of ZnS cluster-like spheres. The thickness of carbon shell is dependent on the dosage of glucose. The carbon-coated ZnS nano-clusters show the same emission as that of pristine ZnS nano-clusters. Exposure of the aqueous dispersion of carbon-coated ZnS products to 980 nm laser can elevate its temperature by 5.1°C in 8 min. It was found that the photothermal conversion effect mainly comes from the carbon component and at the same time, the heterointerface between ZnS and carbon also provides a positive role for it. In addition, the carbon-coated ZnS products can absorb dye molecular with highest adsorption capacity of 36.8 mg/g toward Rhodamine B. The present finding demonstrates their potential applications in photothermal agents, adsorbents, and related fields.

  16. Phosphate chemical conversion coatings on metallic substrates for biomedical application: a review.

    PubMed

    Liu, Bing; Zhang, Xian; Xiao, Gui-yong; Lu, Yu-peng

    2015-02-01

    Phosphate chemical conversion (PCC) technology has been investigated for improving the surface performance of metallic implants in the biomedical field over the last decade. The metallic materials, such as magnesium and its alloys, titanium, pure iron and stainless steel are widely used as orthopedic devices for immobilization of bone fractures in clinic. They were previously studied as metal substrates for PCC coating aiming to modify their biocompatibility and osteoconductivity. Zinc, calcium and zinc-calcium PCC coatings are frequently utilized considering their nature and the end-use. Although PCC coating has been confirmed to potentially improve the bio-performance of metallic implants in vitro and in vivo by many researchers, there are no unified standards or regulations to give quantitative appraisal of its quality and property. As such, an overview of several main phosphate phases together with their properties and behaviors in vitro and in vivo was conducted. The mechanism of phosphating was also briefly discussed. Critical qualities of PCC coating used for biomedical application including corrosion resistance, wettability and bonding strength were analyzed separately. Biological response including in vitro cell investigations and in vivo tissue response were discussed in terms of the cytocompatibility and bioactivity of PCC coating. Further investigations are proposed to develop appropriate performance evaluation measurements by combining conventional technologies and biomedical procedures.

  17. Simultaneous in-line monitoring of the conversion and the coating thickness in UV-cured acrylate coatings by near-infrared reflection spectroscopy.

    PubMed

    Mirschel, Gabriele; Heymann, Katja; Scherzer, Tom

    2010-10-01

    Near-infrared (NIR) reflection spectroscopy was used for in-line analysis of the conversion and the coating thickness (5-20 μm) of UV-cured clear and pigmented acrylate coatings. The quantitative evaluation of the recorded spectra was carried out by partial least-squares (PLS) regression, in particular with the PLS2 algorithm, which allows simultaneous prediction of both parameters. The efficiency of this method was investigated in roll coating experiments at line speeds up to 100 m min(-1). It was shown that the method is able to compensate for the effect of accidental variations of the coating thickness, which inevitably occur upon changes of the line speed, on the prediction of the conversion. Accordingly, the conversion could be determined with a precision of ±2...3%, whereas the error in the measurement of the thickness was found to be about 0.5-1 μm.

  18. Preparation and characterization of selenium incorporated anodic conversion coatings on titanium surfaces for biomedical applications.

    PubMed

    Schreckenbach, J P; Graf, H-L

    2008-01-01

    An anodic spark deposition process was used for preparation of inorganic, glass-ceramic like conversion coatings. The microstructure of the layers was characterized by surface and solid state techniques such as scanning electron microscopy, electron probe microanalysis and Raman spectroscopy. The porous coatings, typically up to 8 mum thick, consist mainly of titanium oxides and amounts of incorporated electrolyte constituents like Se, Ca or P. Beside nano crystalline anatase phases, a mostly amorphous structure is proposed in which network-forming [PO(4)] tetrahedras and [TiO(6)] octahedras in various degrees of condensation are connected. A drastic modification of the film structure was observed when selenium was incorporated into the glassy oxide structure of the coating. In these cases no nano crystalline phases of titanium oxides or other chemical compounds were detected. First cell culture investigations show a significant improvement of the biological properties. Cell proliferation and TGF-beta-expression of these coatings in comparison with commercial pure titanium (CPT) with native titanium oxide films were examined.

  19. Photoelectrochemical conversion in a WO3 coated p-Si photoelectrode: Effect of annealing temperature

    NASA Astrophysics Data System (ADS)

    Yoon, Ki Hyun; Shin, Choul Woo; Kang, Dong Heon

    1997-05-01

    The photoelectrochemical properties of a p-type silicon (100) electrode coated with tungsten oxide thin film were investigated as a function of annealing temperature. The variation in the annealing temperature affected the photocurrent of a WO3/p-Si electrode. A maximum photocurrent was obtained when the 500 Å WO3 thin film coated p-Si electrode was annealed at 350 °C for 1 h. A further increase in the annealing temperature and film thickness degraded the photocurrent. This can be explained in terms of electrical resistivity, carrier concentration, and depletion layer width. A WO3 thin film deposition on the p-Si shifted the flatband potential of the p-Si electrode by 0.3 V in the anodic direction, resulting in an improvement in conversion efficiency. These results are supported by x-ray diffraction, Auger electron spectroscopy, and capacitance measurements.

  20. Squeezed mode conversion in hybrid plasmon polariton waveguide using spin-coated silver film.

    PubMed

    Ha, Thi-Vu-Anh; Park, Hae-Ryeong; Son, Jung-Han; Lee, Myung-Hyun

    2012-07-01

    We designed, fabricated, and characterized a hybrid surface plasmon polariton waveguide (SPP_wg) for mode conversion. The 20-nm-thick silver SPP_wg was fabricated via spin-coating with an aqueous silver ionic complex solution. The structure of the SPP_wg consists of a straight Insulator-Metal-Insulator waveguide (IMl_wg), a lateral tapered Insulator-Metal-Insulator-Metal-Insulator waveguide (tapered_IMIMI_wg), and a straight IMIMI waveguide (IMIMI_wg). An s0 mode size of 12.90 microm x 8.08 microm at a 6-microm-wide IMI_wg was excited by a butt-coupling method at a wavelength of 1550 nm. The s0 mode was converted into an Ss0 mode size of 8.08 microm x 5.65 microm at a 3-microm-wide IMIMI_wg. The mode size was squeezed by approximately 2/3 via a 15-microm-long lateral tapered_IMIMI_wg with a 500-nm-thick central insulator. The coupling loss for mode conversion between the straight IMI_wg and the straight IMIMI_wg was 5.49 dB. The hybrid SPP_wg for mode conversion has the potential to bridge the gap between micron and sub-micron scales in nano plasmonic integrated circuits. In addition, the use of the spin coating method is very cost-effective because films are formed at a low temperature in a short period of time without the need for a vacuum system.

  1. A Comparison of Bulk Precipitated Cerium Oxide Powders and Cerium Conversion Coatings and the Influence of Hydrogen Peroxide on Their Formation (Preprint)

    DTIC Science & Technology

    2006-03-01

    AFRL-ML-WP-TP-2006-422 A COMPARISON OF BULK PRECIPITATED CERIUM OXIDE POWDERS AND CERIUM CONVERSION COATINGS AND THE INFLUENCE OF HYDROGEN...TITLE AND SUBTITLE A COMPARISON OF BULK PRECIPITATED CERIUM OXIDE POWDERS AND CERIUM CONVERSION COATINGS AND THE INFLUENCE OF HYDROGEN PEROXIDE ON...ABSTRACT To better understand the role of hydrogen peroxide in the formation of cerium conversion coatings and precipitates , hydrated cerium oxide

  2. Nanostructured Metal Oxide Coatings for Electrochemical Energy Conversion and Storage Electrodes

    NASA Astrophysics Data System (ADS)

    Cordova, Isvar Abraxas

    The realization of an energy future based on safe, clean, sustainable, and economically viable technologies is one of the grand challenges facing modern society. Electrochemical energy technologies underpin the potential success of this effort to divert energy sources away from fossil fuels, whether one considers alternative energy conversion strategies through photoelectrochemical (PEC) production of chemical fuels or fuel cells run with sustainable hydrogen, or energy storage strategies, such as in batteries and supercapacitors. This dissertation builds on recent advances in nanomaterials design, synthesis, and characterization to develop novel electrodes that can electrochemically convert and store energy. Chapter 2 of this dissertation focuses on refining the properties of TiO2-based PEC water-splitting photoanodes used for the direct electrochemical conversion of solar energy into hydrogen fuel. The approach utilized atomic layer deposition (ALD); a growth process uniquely suited for the conformal and uniform deposition of thin films with angstrom-level thickness precision. ALD's thickness control enabled a better understanding of how the effects of nitrogen doping via NH3 annealing treatments, used to reduce TiO2's bandgap, can have a strong dependence on TiO2's thickness and crystalline quality. In addition, it was found that some of the negative effects on the PEC performance typically associated with N-doped TiO2 could be mitigated if the NH 3-annealing was directly preceded by an air-annealing step, especially for ultrathin (i.e., < 10 nm) TiO2 films. ALD was also used to conformally coat an ultraporous conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold with an ultrathin layer of TiO2. The integration of these ultrathin films and the oxide nanoparticles resulted in a heteronanostructure design with excellent PEC water oxidation photocurrents (0.7 mA/cm2 at 0 V vs. Ag/AgCl) and charge transfer efficiency. In Chapter 3, two innovative

  3. In-line determination of the conversion in acrylate coatings after UV curing using near-infrared reflection spectroscopy

    NASA Astrophysics Data System (ADS)

    Scherzer, Tom; Müller, Sabine; Mehnert, Reiner; Volland, Arne; Lucht, Hartmut

    2005-07-01

    Near-infrared (NIR) reflection spectroscopy was used to determine the conversion of acrylic double bonds after UV photopolymerization. Quantitative analysis of the spectra was performed with chemometric methods using FTIR spectroscopy for calibration. Moreover, it was shown that the calibration of the PLS algorithm can also be performed directly to specific properties of the coatings such as their hardness which responds extremely sensitively even to small changes of the conversion. In-line monitoring of the conversion by NIR spectroscopy was carried out for acrylate coatings with a thickness of some micrometers applied to polymer foils and panels and for thick layers of UV-curable adhesives on the basis of acrylic hot-melts. The effect of changes of the irradiation dose, the emission spectrum of the UV source and other parameters on the conversion was studied.

  4. Polyaniline-coated upconversion nanoparticles with upconverting luminescent and photothermal conversion properties for photothermal cancer therapy.

    PubMed

    Xing, Yadong; Li, Luoyuan; Ai, Xicheng; Fu, Limin

    In this study, we developed a nanosystem based on upconversion nanoparticles (UCNPs) coated with a layer of polyaniline nanoparticles (PANPs). The UCNP induces upconversion luminescence for imaging and photothermal conversion properties are due to PANPs. In vitro experiments showed that the UCNPs-PANPs were nontoxic to cells even at a high concentration (800 µg mL(-1)). Blood analysis and histological experiments demonstrated that the UCNPs-PANPs exhibited no apparent toxicity in mice in vivo. Besides their efficacy in photothermal cancer cell ablation, the UCNP-PANP nanosystem was found to achieve an effective in vivo tumor ablation effect after irradiation using an 808 nm laser. These results demonstrate the potential of the hybrid nanocomposites for use in imaging-guided photothermal therapy.

  5. Polyaniline-coated upconversion nanoparticles with upconverting luminescent and photothermal conversion properties for photothermal cancer therapy

    PubMed Central

    Xing, Yadong; Li, Luoyuan; Ai, Xicheng; Fu, Limin

    2016-01-01

    In this study, we developed a nanosystem based on upconversion nanoparticles (UCNPs) coated with a layer of polyaniline nanoparticles (PANPs). The UCNP induces upconversion luminescence for imaging and photothermal conversion properties are due to PANPs. In vitro experiments showed that the UCNPs-PANPs were nontoxic to cells even at a high concentration (800 µg mL−1). Blood analysis and histological experiments demonstrated that the UCNPs-PANPs exhibited no apparent toxicity in mice in vivo. Besides their efficacy in photothermal cancer cell ablation, the UCNP-PANP nanosystem was found to achieve an effective in vivo tumor ablation effect after irradiation using an 808 nm laser. These results demonstrate the potential of the hybrid nanocomposites for use in imaging-guided photothermal therapy. PMID:27621625

  6. In situ pH measurement during the formation of conversion coatings on an aluminum alloy (AA2024).

    PubMed

    Li, Liangliang; Desouza, Annika Laura; Swain, Greg M

    2013-08-07

    The measurement of interfacial pH change is important for understanding the formation mechanism of conversion coatings that are used to protect metals from corrosion. In this work, we used a tungsten microelectrode to measure the interfacial pH change near the surface of an aluminium alloy (AA2024) during the formation of two conversion coatings: (i) a trivalent chromium pretreatment (TCP) and (ii) a Ti-based, non-chromium-containing coating. The tungsten microelectrode exhibited an open circuit potential (OCP) that changed linearly as a function of the solution pH with a slope of -64 mV per pH. The microelectrode was positioned near the AA2024-T3 surface and its potential was measured as a function of time along with the OCP of the alloy sample during formation of the two coatings. The microelectrode exhibited a negative shift in potential immediately upon initiation of the coating formation, consistent with a significant increase in the interfacial pH of 2-6 units depending on the coating system. The pH increase is attributed to proton-consuming cathodic reactions that occur on the alloy surface once the passivating oxide layer is dissolved: hydrogen evolution and oxygen reduction. The increased pH causes the hydrolysis of the soluble fluorometalate precursor species in the baths, which precipitate forming a hydrated metal oxide coating (e.g., ZrO2·nH2O).

  7. In-situ preparation of scholzite conversion coatings on titanium and Ti-6Al-4V for biomedical applications.

    PubMed

    Liu, Bing; Shi, Xiao-Ming; Xiao, Gui-Yong; Lu, Yu-Peng

    2017-05-01

    A scholzite (CaZn2(PO4)2·2H2O) coating was prepared in situ on commercially pure titanium (cpTi) and Ti-6Al-4V (Ti64) substrates using the chemical conversion technology, and its phase composition and microstructure, as well as mechanical, chemical and biological properties were investigated to explore potential applications as a bioactive coating on bone implants. It is indicated that the coating consists mainly of monoclinic scholzite crystals with nano-thick laminar morphology. The crystals on cpTi aggregate to flower-like particles with the diameter of 5-10μm, while form a network structure homogeneously on Ti64. The scratch test shows that the interfacial bonding strength between the coatings and substrates is higher than 40N. Electrochemical measurements indicate that the corrosion behavior of the coatings is not inferior compared with that of oxide film on substrates. MG63 osteoblast-like cells show good adherence and significantly proliferation and differentiation characteristics on the scholzite coated cpTi and Ti64 (p<0.05) in in-vitro cell tests, demonstrating the cytocompatibility of Ti is significantly improved by the scholzite coating. It is suggested that the scholzite coating might be a promising option in hard tissue replacements for early osteogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Influence of bath PH value on microstructure and corrosion resistance of phosphate chemical conversion coating on sintered Nd-Fe-B permanent magnets

    NASA Astrophysics Data System (ADS)

    Ding, Xia; Xue, Long-fei; Wang, Xiu-chun; Ding, Kai-hong; Cui, Sheng-li; Sun, Yong-cong; Li, Mu-sen

    2016-10-01

    The effect of bath PH value on formation, microstructure and corrosion resistance of the phosphate chemical conversion (PCC) coatings as well as the effect on the magnetic property of the magnets is investigated in this paper. The results show that the coating mass and thickness increase with the decrease of the bath PH value. Scanning electron microscopy observation demonstrates that the PCC coatings are in a blocky structure with different grain size. Transmission electron microscope and X-ray diffractometer tests reveal the coatings are polycomponent and are mainly composed of neodymium phosphate hydrate and praseodymium phosphate hydrate. The electrochemical analysis and static immersion corrosion test show the corrosion resistance of the PCC coatings prepared at bath PH value of 0.52 is worst. Afterwards the corrosion resistance increases first and then decreases with the increasing of the bath PH values. The magnetic properties of all the samples with PCC treatment are decreased. The biggest loss is occurred when the bath PH value is 0.52. Taken together, the optimum PH range of 1.00-1.50 for the phosphate solution has been determined.

  9. Blood compatibility of zinc-calcium phosphate conversion coating on Mg-1.33Li-0.6Ca alloy

    NASA Astrophysics Data System (ADS)

    Zou, Yu-Hong; Zeng, Rong-Chang; Wang, Qing-Zhao; Liu, Li-Jun; Xu, Qian-Qian; Wang, Chuang; Liu, Zhi-Wei

    2016-09-01

    Magnesium alloys as a new class of biomaterials possess biodegradability and biocompatibility in comparison with currently used metal implants. However, their rapid corrosion rates are necessary to be manipulated by appropriate coatings. In this paper, a new attempt was used to develop a zinc-calcium phosphate (Zn-Ca-P) conversion coating on Mg-1.33Li-0.6Ca alloys to increase the biocompatibility and improve the corrosion resistance. In vitro blood biocompatibility of the alloy with and without the Zn-Ca-P coating was investigated to determine its suitability as a degradable medical biomaterial. Blood biocompatibility was assessed from the hemolysis test, the dynamic cruor time test, blood cell count and SEM observation of the platelet adhesion to membrane surface. The results showed that the Zn-Ca-P coating on Mg-1.33Li-0.6Ca alloys had good blood compatibility, which is in accordance with the requirements for medical biomaterials.

  10. Treatment outcome for children and adolescents with conversion disorder.

    PubMed

    Turgay, A

    1990-10-01

    This paper describes the clinical impressions of conversion disorders developed after long term in-depth clinical work with 137 children and adolescents and their families. Almost half of the 89 patients who were directly treated and followed by the author through an integrative child and family therapy approach recovered less than two weeks after the initiation of the treatment. Only three out of 89 patients required longer than four weeks for recovery. The rest responded well to the therapy and recovered with two to four weeks of treatment. Factors associated with positive treatment outcome are: younger age of patient, healthy personality characteristics, lack of psychopathology, insight and treatment compliance, healthy family functioning, acceptance by the family of the psychological nature of the illness, positive feelings towards the child and the family by the staff, lack of internal conflict and inflexible neurotic defences, and early therapeutic interventions. It was found that child and adolescent patients with conversion disorders responded quite well to an integrative, condensed treatment approach.

  11. Structure and function of ferricyanide in the formation of chromate conversion coatings on aluminum aircraft alloy

    SciTech Connect

    Xia, L.; McCreery, R.L.

    1999-10-01

    Raman and infrared spectroscopy were used to determine the structure of Fe(CN){sup {minus}3}{sub 6} and its reaction products in chromate conversion coatings (CCCs) on AA 2024-T3 aluminum aircraft alloy. In addition, Raman spectroscopy was used to monitor CCC growth rates and their dependence on coating bath composition. The IR and Raman spectra of the air-dried CCC corresponded to those of Berlin green, a Fe{sup +3}-CN-FE{sup +3} polymer, and Fe(CN){sub 6}{sup {minus}3} physisorbed on Cr(OH){sub 3}. No other cyano-containing products were observed. When Fe(CN){sub 6}{sup {minus}3} was excluded from the coating bath, CCC formation rate greatly decreased. In addition, it was observed that Fe(CN){sub 6}{sup {minus}3} could rapidly oxidize AA 2024-T3, and Fe(CN){sub 6}{sup {minus}4} rapidly reduced Cr(VI) in bath conditions. These results indicate a redox mediation action for Fe(CN){sub 6}{sup {minus}3/{minus}4}, which greatly increases the reduction of Cr(VI) to Cr(III) by the alloy. This process is normally quite slow, and redox mediation by Fe(CN){sub 6}{sup {minus}3} is critical to CCC formation. IrCl{sub 6}{sup {minus}3}/{sup {minus}2} could substitute for Fe(CN){sub 6}{sup {minus}3/{minus}4} to produce a chromate film with properties very similar to a conventional CCC. The results establish redox mediation as the mechanism of acceleration of CCC formation, but provide no evidence for any additional role of Fe(CN){sub 6}{sup {minus}3/{minus}4} to produce a chromate film with properties very similar to a conventional CCC. The results establish redox mediation as the mechanism of acceleration of CCC formation, but provide no evidence for any additional role of Fe(CN){sub 6}{sup {minus}3/{minus}4} in corrosion protection.

  12. Phase Conjugated and Transparent Wavelength Conversions of Nyquist 16-QAM Signals Employing a Single-Layer Graphene Coated Fiber Device

    PubMed Central

    Hu, Xiao; Zeng, Mengqi; Long, Yun; Liu, Jun; Zhu, Yixiao; Zou, Kaiheng; Zhang, Fan; Fu, Lei; Wang, Jian

    2016-01-01

    We fabricate a nonlinear optical device based on a fiber pigtail cross-section coated with a single-layer graphene grown by chemical vapor deposition (CVD) method. Using the fabricated graphene-assisted nonlinear optical device and employing Nyquist 16-ary quadrature amplitude modulation (16-QAM) signal, we experimentally demonstrate phase conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in graphene. We study the conversion efficiency as functions of the pump power and pump wavelength and evaluate the bit-error rate (BER) performance. We also compare the time-varying symbol sequence for graphene-assisted phase conjugated and transparent wavelength conversions of Nyquist 16-QAM signal. PMID:26932470

  13. Phase Conjugated and Transparent Wavelength Conversions of Nyquist 16-QAM Signals Employing a Single-Layer Graphene Coated Fiber Device

    NASA Astrophysics Data System (ADS)

    Hu, Xiao; Zeng, Mengqi; Long, Yun; Liu, Jun; Zhu, Yixiao; Zou, Kaiheng; Zhang, Fan; Fu, Lei; Wang, Jian

    2016-03-01

    We fabricate a nonlinear optical device based on a fiber pigtail cross-section coated with a single-layer graphene grown by chemical vapor deposition (CVD) method. Using the fabricated graphene-assisted nonlinear optical device and employing Nyquist 16-ary quadrature amplitude modulation (16-QAM) signal, we experimentally demonstrate phase conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in graphene. We study the conversion efficiency as functions of the pump power and pump wavelength and evaluate the bit-error rate (BER) performance. We also compare the time-varying symbol sequence for graphene-assisted phase conjugated and transparent wavelength conversions of Nyquist 16-QAM signal.

  14. Phase Conjugated and Transparent Wavelength Conversions of Nyquist 16-QAM Signals Employing a Single-Layer Graphene Coated Fiber Device.

    PubMed

    Hu, Xiao; Zeng, Mengqi; Long, Yun; Liu, Jun; Zhu, Yixiao; Zou, Kaiheng; Zhang, Fan; Fu, Lei; Wang, Jian

    2016-03-02

    We fabricate a nonlinear optical device based on a fiber pigtail cross-section coated with a single-layer graphene grown by chemical vapor deposition (CVD) method. Using the fabricated graphene-assisted nonlinear optical device and employing Nyquist 16-ary quadrature amplitude modulation (16-QAM) signal, we experimentally demonstrate phase conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in graphene. We study the conversion efficiency as functions of the pump power and pump wavelength and evaluate the bit-error rate (BER) performance. We also compare the time-varying symbol sequence for graphene-assisted phase conjugated and transparent wavelength conversions of Nyquist 16-QAM signal.

  15. Mesoporous-silica-coated up-conversion fluorescent nanoparticles for photodynamic therapy.

    PubMed

    Qian, Hai Sheng; Guo, Hui Chen; Ho, Paul Chi-Lui; Mahendran, Ratha; Zhang, Yong

    2009-10-01

    Near-infrared (NIR)-to-visible up-conversion fluorescent nanoparticles have potential to be used for photodynamic therapy (PDT) in deep tissue because NIR light can penetrate thick tissue due to weak absorption in the optical window. Here a uniform layer of mesoporous silica is coated onto NaYF(4) up-converting nanocrystals, with a large surface area of approximately 770 m(2) g(-1) and an average pore size of 2 nm. A photosensitizer, zinc phthalocyanine, is incorporated into the mesoporous silica. Upon excitation by a NIR laser, the nanocrystals convert NIR light to visible light, which further activates the photosensitizer to release reactive singlet oxygen to kill cancer cells. The photosensitizer encapsulated in mesoporous silica is protected from degradation in the harsh biological environment. It is demonstrated that the photosensitizers loaded into the porous silica shell of the nanoparticles are not released out of the silica while they continuously produce singlet oxygen upon excitation by a NIR laser. The nanoparticles are reusable as the photosensitizers encapsulated in the silica are removed by soaking in ethanol.

  16. Case history advanced coatings for water treatment plant components

    SciTech Connect

    Stephenson, L.D.; Kumar, A.

    2008-12-15

    Components of water treatment plants (WTPs) are susceptible to corrosion from constant immersion in water. A case history of corrosion and proximity to chlorine problems and their treatment at an Army WTP is presented. Solutions included using high micro-silica restoration mortar and advanced coal tar epoxy coatings.

  17. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    NASA Astrophysics Data System (ADS)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-11-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  18. A review of biological sulfate conversions in wastewater treatment.

    PubMed

    Hao, Tian-wei; Xiang, Peng-yu; Mackey, Hamish R; Chi, Kun; Lu, Hui; Chui, Ho-kwong; van Loosdrecht, Mark C M; Chen, Guang-Hao

    2014-11-15

    Treatment of waters contaminated with sulfur containing compounds (S) resulting from seawater intrusion, the use of seawater (e.g. seawater flushing, cooling) and industrial processes has become a challenging issue since around two thirds of the world's population live within 150 km of the coast. In the past, research has produced a number of bioengineered systems for remediation of industrial sulfate containing sewage and sulfur contaminated groundwater utilizing sulfate reducing bacteria (SRB). The majority of these studies are specific with SRB only or focusing on the microbiology rather than the engineered application. In this review, existing sulfate based biotechnologies and new approaches for sulfate contaminated waters treatment are discussed. The sulfur cycle connects with carbon, nitrogen and phosphorus cycles, thus a new platform of sulfur based biotechnologies incorporating sulfur cycle with other cycles can be developed, for the removal of sulfate and other pollutants (e.g. carbon, nitrogen, phosphorus and metal) from wastewaters. All possible electron donors for sulfate reduction are summarized for further understanding of the S related biotechnologies including rates and benefits/drawbacks of each electron donor. A review of known SRB and their environmental preferences with regard to bioreactor operational parameters (e.g. pH, temperature, salinity etc.) shed light on the optimization of sulfur conversion-based biotechnologies. This review not only summarizes information from the current sulfur conversion-based biotechnologies for further optimization and understanding, but also offers new directions for sulfur related biotechnology development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. In situ surface studies of conversion coatings for steel and aluminum. Final report, 15 April 1989-14 September 1992

    SciTech Connect

    White, H.W.; Mansfeld, F.; Bryant, P.

    1992-11-10

    The primary goals of the work were to develop mechanisms of corrosion protection for cerium based surface layers on aluminum alloys and on polyacrylic acid (PAA) complexed zinc phosphate conversion coatings on steel. Atomic force microscopy (AFM) using tunnel current control was developed and applied to several problems. The cerium based coatings on AI 6061-T6 are shown to consist of two principle components--a poorly ordered monohydrated aluminum oxide, and an insoluble cerium oxide which forms at areas concentrated with impurities and alloying elements. Electrochemical action during the surface modification process fosters the precipitation of cerium compounds which inhibit further attack. The addition of high molecular weight PAA to the phosphating bath can significantly improve both resistance to corrosion and top-coat adherence of zinc phosphate conversion coatings on steel. Raman spectra showed the compositions of both unmodified and PAA modified films to be zinc phosphate dihydrate. Single crystallite surfaces were imaged using AFM. The morphologies of the unmodified and modified films were in general quite similar, but subtle differences were apparent. Several other projects involving surface layers and adsorbates were carried out and are described.

  20. Predicting Social Anxiety Treatment Outcome Based on Therapeutic Email Conversations.

    PubMed

    Hoogendoorn, Mark; Berger, Thomas; Schulz, Ava; Stolz, Timo; Szolovits, Peter

    2017-09-01

    Predicting therapeutic outcome in the mental health domain is of utmost importance to enable therapists to provide the most effective treatment to a patient. Using information from the writings of a patient can potentially be a valuable source of information, especially now that more and more treatments involve computer-based exercises or electronic conversations between patient and therapist. In this paper, we study predictive modeling using writings of patients under treatment for a social anxiety disorder. We extract a wealth of information from the text written by patients including their usage of words, the topics they talk about, the sentiment of the messages, and the style of writing. In addition, we study trends over time with respect to those measures. We then apply machine learning algorithms to generate the predictive models. Based on a dataset of 69 patients, we are able to show that we can predict therapy outcome with an area under the curve of 0.83 halfway through the therapy and with a precision of 0.78 when using the full data (i.e., the entire treatment period). Due to the limited number of participants, it is hard to generalize the results, but they do show great potential in this type of information.

  1. Bioresponsive polymer coated drug nanorods for breast cancer treatment

    NASA Astrophysics Data System (ADS)

    Laemthong, Tunyaboon; Kim, Hannah H.; Dunlap, Kelly; Brocker, Caitlin; Barua, Dipak; Forciniti, Daniel; Huang, Yue-Wern; Barua, Sutapa

    2017-01-01

    Ineffective drug release at the target site is among the top challenges for cancer treatment. This reflects the facts that interaction with the physiological condition can denature active ingredients of drugs, and low delivery to the disease microenvironment leads to poor therapeutic outcomes. We hypothesize that depositing a thin layer of bioresponsive polymer on the surface of drug nanoparticles would not only protect drugs from degradation but also allow the release of drugs at the target site. Here, we report a one-step process to prepare bioresponsive polymer coated drug nanorods (NRs) from liquid precursors using the solvent diffusion method. A thin layer (10.3 ± 1.4 nm) of poly(ε-caprolactone) (PCL) polymer coating was deposited on the surface of camptothecin (CPT) anti-cancer drug NRs. The mean size of PCL-coated CPT NRs was 500.9 ± 91.3 nm length × 122.7 ± 10.1 nm width. The PCL polymer coating was biodegradable at acidic pH 6 as determined by Fourier transform infrared spectroscopy. CPT drugs were released up to 51.5% when PCL coating dissolved into non-toxic carboxyl and hydroxyl groups. Trastuzumab (TTZ), a humanized IgG monoclonal antibody, was conjugated to the NR surface for breast cancer cell targeting. Combination treatments using CPT and TTZ decreased the HER-2 positive BT-474 breast cancer cell growth by 66.9 ± 5.3% in vitro. These results suggest effective combination treatments of breast cancer cells using bioresponsive polymer coated drug delivery.

  2. Effect of preliminary vacuum plasma treatment on coating adhesion

    NASA Astrophysics Data System (ADS)

    Slabodchikov, Vladimir A.; Borisov, Dmitry P.; Kuznetsov, Vladimir M.

    2016-11-01

    The paper presents research results on the adhesion properties of Si coatings synthesized by different methods and under different conditions of preliminary vacuum ion plasma treatment of substrates with subsequent magnetron sputtering. The substrate surface was pretreated with low-energy ion beams, high-energy ion beams, gas discharge plasma, and plasma produced by a magnetron sputtering system. The vacuum conditions (pump type, pressure, etc.), the ion current density, and the bias parameters (pulse repetition frequency and duration) were varied. The research results demonstrate a considerable effect of plasma immersion ion implantation on the adhesion of Si coatings to NiTi substrates.

  3. Conversion Disorder, Functional Neurological Symptom Disorder, and Chronic Pain: Comorbidity, Assessment, and Treatment.

    PubMed

    Tsui, Patricia; Deptula, Andrew; Yuan, Derek Y

    2017-06-01

    This paper examines the overlap of conversion disorder with chronic pain conditions, describes ways to assess for conversion disorder, and provides an overview of evidence-based treatments for conversion disorder and chronic pain, with a focus on conversion symptoms. Conversion disorder is a significant problem that warrants further study, given that there are not many well-established guidelines. Accurate and timely assessment should help move treatment in a more fruitful direction and avoid unnecessary medical interventions. Advances in neuroimaging may also help further our understanding of conversion disorder. Creating a supportive environment and a collaborative treatment relationship and improving understanding of conversion symptoms appear to help individuals diagnosed with conversion disorder engage in appropriate treatments. Novel uses of earlier treatments, such as hypnosis and psychodynamic approaches, could potentially be beneficial and require a more vigorous and systematic study. There are treatments that produce significant improvements in functioning and reduction of physical symptoms from conversion disorder even for very severe cases. Hypnotherapy, cognitive behavioral therapy, and inpatient multidisciplinary treatment with intensive physiotherapy for severe cases have the most evidence to support reduction of symptoms. Components of treatment for conversion disorder overlap with treatments for chronic pain and can be used together to produce therapeutic effects for both conditions. Treatment needs to be tailored for each individual's specific symptoms.

  4. A correlation between salt spray and electrochemical impedance spectroscopy test results for conversion-coated aluminum alloys

    SciTech Connect

    Buchheit, R.G.; Cunningham, M.; Jensen, H.; Kendig, M.W.; Martinez, M.A.

    1998-01-01

    The corrosion resistance of 33 inorganic conversion coatings applied to five aluminum alloys was tested by salt spray exposure and electrochemical impedance spectroscopy (EIS). Results were evaluated to determine if a relationship existed. Individual salt spray test panels, with an area of 30 in.{sup 2} (194 cm{sup 2}), were inspected visually at regular intervals up to 168 h of exposure. At each inspection interval, panels were assigned a pass rank if <5 pits were observed, or a fail rank if >5 pits were observed. EIS data were analyzed using a simple equivalent circuit which yielded a coating resistance (R{sub c}), which was used as a figure of merit to assess coating performance. Examination of the data showed both tests could be sensitive discriminators of corrosion protection, but that EIS was more discriminating in the extremes of coating performance. Analysis showed the probability of achieving a passing salt spray result increased as R{sub c} increased. In the regimes where both tests were sensitive, regression analysis showed a linear relationship existed for each alloy substrate between the log of R{sub c} and the probability of a coating meeting the pass/fail criterion in salt spray. Based upon these relationships, threshold R{sub c} values were proposed to define the minimum value for which a given coating can be expected to attain a passing result in a 168-h salt spray test. These values were 2 {times} 10{sup 6} {Omega}-cm{sup 2} to 5 {times} 10{sup 6} {Omega}-cm{sup 2} for Al 356 (UNS A13560), Al 2024-T3 (UNS A92024), and Al 6061-T6 (UNS A96061); 1.5 {times} 10{sup 7} for Al 7075-T6 (UNS A97075); and 2.3 {times} 10{sup 6} {Omega}-cm{sup 2} for Al 3003 (UNS A93003).

  5. Photoelectrochemical conversion in a WO{sub 3} coated p-Si photoelectrode: Effect of annealing temperature

    SciTech Connect

    Yoon, K.H.; Shin, C.W.; Kang, D.H.

    1997-05-01

    The photoelectrochemical properties of a p-type silicon (100) electrode coated with tungsten oxide thin film were investigated as a function of annealing temperature. The variation in the annealing temperature affected the photocurrent of a WO{sub 3}/p-Si electrode. A maximum photocurrent was obtained when the 500 {Angstrom} WO{sub 3} thin film coated p-Si electrode was annealed at 350{degree}C for 1 h. A further increase in the annealing temperature and film thickness degraded the photocurrent. This can be explained in terms of electrical resistivity, carrier concentration, and depletion layer width. A WO{sub 3} thin film deposition on the p-Si shifted the flatband potential of the p-Si electrode by 0.3 V in the anodic direction, resulting in an improvement in conversion efficiency. These results are supported by x-ray diffraction, Auger electron spectroscopy, and capacitance measurements. {copyright} {ital 1997 American Institute of Physics.}

  6. Investigation of anodic oxide coatings on zirconium after heat treatment

    NASA Astrophysics Data System (ADS)

    Sowa, Maciej; Dercz, Grzegorz; Suchanek, Katarzyna; Simka, Wojciech

    2015-08-01

    Herein, results of heat treatment of zirconium anodised under plasma electrolytic oxidation (PEO) conditions at 500-800 °C are presented. The obtained oxide films were investigated by means of SEM, XRD and Raman spectroscopy. The corrosion resistance of the zirconium specimens was evaluated in Ringer's solution. A bilayer oxide coatings generated in the course of PEO of zirconium were not observed after the heat treatment. The resulting oxide layers contained a new sublayer located at the metal/oxide interface is suggested to originate from the thermal oxidation of zirconium. The corrosion resistance of the anodised metal was improved after the heat treatment.

  7. Mg substituted apatite coating from alkali conversion of acidic calcium phosphate.

    PubMed

    Navarro da Rocha, Daniel; Cruz, Leila Rosa de Oliveira; de Campos, José Brant; Marçal, Rubens L Santana Blazutti; Mijares, Dindo Q; Coelho, Paulo G; Prado da Silva, Marcelo H

    2017-01-01

    In this work, two solutions were developed: the first, rich in Ca(2+), PO4(3-) ions and the second, rich in Ca(2+), PO4(3-) and Mg(2+), defined as Mg-modified precursor solution. For each Mg-modified precursor solution, the concentrations of Mg(2+) ions were progressively increased by 5%, 10% and 15%wt. The aims of this research were to investigate the influence of magnesium ions substitution in calcium phosphate coatings on titanium surface and to evaluate these coatings by bioactivity assay in McCoy culture medium. The obtained coatings were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis, and the presence of Mg ions was confirmed by the inductively coupled plasma atomic emission spectroscopy (ICP) analysis. In vitro bioactivity assay in McCoy culture medium showed bioactivity after 14days in incubation for the HA and 10% Mg-monetite coatings. The high chemical stability of Mg-HA coatings was verified by the bioactivity assays, and no bone-like apatite deposition, characteristic of bioactivity, was observed for Mg-HA coatings, for the time period used in this study. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. High-coverage organic-inorganic perovskite film fabricated by double spin coating for improved solar power conversion and amplified spontaneous emission

    NASA Astrophysics Data System (ADS)

    Matsushima, Toshinori; Inoue, Munetomo; Fujihara, Takashi; Terakawa, Shinobu; Qin, Chuanjiang; Sandanayaka, Atula S. D.; Adachi, Chihaya

    2016-09-01

    We demonstrate that double spin coating, where a perovskite film is covered with another perovskite film, can increase substrate coverage from 81% to 97% along with an increase of film thickness from 151 ± 17 to 246 ± 18 nm. The increased substrate coverage by double coating improves the solar power conversion efficiency from 7.1 ± 0.6 to 10.3 ± 1.0%, an approximate 1.5-fold increase. Additionally, a double-coated film of higher substrate coverage exhibits amplified spontaneous emission (ASE) while a single-coated film of lower substrate coverage does not exhibit ASE. Double coating is an attractive method for increasing substrate coverage and improving solar power conversion and ASE.

  9. Improved gastrointestinal symptoms and quality of life after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant patients receiving tacrolimus.

    PubMed

    Hwang, Hyeon Seok; Hyoung, Bok Jin; Kim, Sol; Oh, Ha Young; Kim, Yon Su; Kim, Jung Kyung; Kim, Yeong Hoon; Kim, Yong Lim; Kim, Chan Duck; Shin, Gyu Tae; Yang, Chul Woo

    2010-12-01

    It is reported that a conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) relieves gastrointestinal (GI) symptom burden and improves health-related quality of life (HRQoL). However, it is unclear whether renal transplant recipients using tacrolimus receive the same benefit from the conversion. In this prospective, multi-center, open-label trial, patients were categorized into two groups by their GI symptom screening. Equimolar EC-MPS (n=175) was prescribed for patients with GI burdens; those with no complaints remained on MMF (n=83). Gastrointestinal Symptom Rating Scale (GSRS) and Gastrointestinal Quality of Life Index (GIQLI) were evaluated at baseline and after one month. Patients and physicians completed Overall Treatment Effect (OTE) at one month. EC-MPS-converted patients had worse GSRS and GIQLI scores at baseline than MMF-continued patients (all P<0.001). Significant improvements in GSRS and GIQLI scores were observed for EC-MPS-converted patients at one month, but MMF-continued patients showed worsened GSRS scores (all P<0.05). OTE scale indicated that EC-MPS patients improved in overall GI symptoms and HRQoL more than MMF patients did (P<0.001). In tacrolimus-treated renal transplant recipients with GI burdens, a conversion from MMF to EC-MPS improves GI-related symptoms and HRQoL.

  10. Synthesis of superhydrophobic alumina membrane: Effects of sol-gel coating, steam impingement and water treatment

    NASA Astrophysics Data System (ADS)

    Ahmad, N. A.; Leo, C. P.; Ahmad, A. L.

    2013-11-01

    Ceramic membranes possess natural hydrophilicity thus tending to absorb water droplets. The absorption of water molecules on membrane surface reduces their application in filtration, membrane distillation, osmotic evaporation and membrane gas absorption. Fluoroalkylsilane (FAS) grafting allows the conversion of hydrophilic ceramic membranes into superhydrophobic thin layer, but it usually introduces a great increment of mass transfer resistance. In this study, superhydrophobic alumina membranes were synthesized by dip coating alumina support into sol-gel and grafted with the fluoroalkylsilane (FAS) named (heptadecafluoro-1,1,2,2-tetra hydrodecyl) triethoxysilane. Steam impingement and water treatment acted as additional steps to generate surface roughness on sol-gel and most importantly to reduce mass transfer resistance. Superhydrophobic alumina membrane with high water contact angle (158.4°) and low resistance (139.5 ± 24.9 G m-1) was successfully formed when the alumina membrane was dip coated into sol-gel for 7 s, treated with steam impingement for 1 min and immersed in hot water at 100 °C. However, the mass transfer resistance was greatly induced to 535.6 ± 23.5 G m-1 when the dip coating time was increased to 60 s. Long dip coating time contributes more on the blockage of porous structure rather than creates a thin film on the top of membrane surface. Reducing the pore size and porosity significantly due to increase of coating molecules deposited on the membrane. Steam impingement for 1 min promoted the formation of cones and valleys on the sol-gel, but the macro-roughness was destroyed when the steam impingement duration was extended to more than 3 min. The immersions of membranes into hot water at temperatures higher than 60 °C encouraged the formation of boehmite which enhances the formation of additional roughness and enlarges pore size greatly. Thus, this work showed that the formation of superhydrophobic alumina membrane with low resistance is

  11. Preparation of conversion coating on Ti-6Al-4V alloy in mixed solution of phytic acid and ammonium fluoride through chemical modification

    NASA Astrophysics Data System (ADS)

    Li, Lanlan; He, Jian; Yang, Xu

    2016-05-01

    Conversion coatings on Ti-6Al-4V alloy was prepared through chemical modification in phytic acid and ammonium fluoride mixed solution. The influences of pH, time and the composition of solution on the microstructure of alloy surface were investigated. Scanning electron microscopy was used to observe the microstructure. The chemical composition of alloy surface before and after modification was investigated by energy dispersive X-ray spectroscopy. The results indicated that a conversion coating could be formed on the Ti-6Al-4V alloy in a mixed solution of phytic acid and ammonium fluoride, the growth and microstructure of the conversion coatings were critically dependent on the pH, time and concentration of phytic acid and ammonium fluoride. In 100 mg/ml phytic acid containing 125 mg/ml ammonium fluoride solution with a pH of 6, a compact conversion coating with the thickness of about 4.7 μm formed after 30 min immersion on Ti-6Al-4V alloy surface. The preliminary evaluation of bioactivity of conversion coating was performed by in vitro cell experiments. The results showed that this chemical modification method is a promising surface modification technique for Ti-6Al-4V alloy inplants.

  12. Improved power conversion efficiency for dye-sensitized solar cells using a subwavelength-structured antireflective coating

    NASA Astrophysics Data System (ADS)

    Chou, Chun-Chi; Tsao, Kuan-Yi; Wu, Chih-Chung; Yang, Hongta; Chen, Chih-Ming

    2015-02-01

    Large-scale, subwavelength-structured nanodome arrays were successfully fabricated using simple, scalable bottom-up colloidal (nanosphere) lithography on a glass substrate as an efficient antireflective photoanode for dye-sensitized solar cells (DSSCs). A self-assembled monolayer of close-packed colloidal crystals (silica) was used as a structural template to pattern the two-dimensional subwavelength-structured nanodome arrays, which function as an efficient antireflective coating due to the graded refractive index across the interface between the air and specific nanodome array structure. The light harvesting for a DSSC with a subwavelength-structured antireflective coating was enhanced due to the improved broadband antireflectivity. Adjusting the nanodome size yielded a short-circuit current density (JSC) of 15.88 mA/cm2 with a power conversion efficiency (PCE) of 8.82%, which were both better than the reference cell without a subwavelength-structured antireflective coating (JSC = 15.26 mA/cm2 and PCE = 8.45%).

  13. Surface chemistry and corrosion behavior of aluminum-copper systems: Air-formed films to complex conversion coatings

    NASA Astrophysics Data System (ADS)

    Chidambaram, Devicharan

    Understanding the mechanism of corrosion inhibition by carcinogenic chromates is critical to the development of environmentally safe coatings containing benign chromate substitutes. An integrated approach to correlate the surface chemistry and corrosion behavior of a wide range of systems has been undertaken. Electrochemical behavior was studied by open circuit potential (OCP) measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Surface chemistry was studied using variable-angle X-ray photoelectron spectroscopy (VAXPS), X-ray absorption near edge spectroscopy (XANES), secondary ion mass spectroscopy (SIMS), infrared spectroscopy and synchrotron infrared micro spectroscopy (SIRMS) and Raman spectroscopy. Using SIRMS, the ASTM recommended acetone degreasing was shown to initiate pitting of AA2024-T3 via photochemical formation of acetic acid. Due to the known tendency for photoreduction of Cr6+(3d0) following soft X-ray dosage during XPS, a novel method has been developed to prevent this reduction. This method yields, for the first time, an accurate determination of the Cr6+ content of a CCC. The pretreatment of the alloy prior to conversion coating has been shown to have significant influence on the surface intermetallic distribution, composition and corrosion resistance of the initial oxide film and subsequent conversion coating. AlconoxRTM pretreatment was found to result in a highly protective surface film that inhibits the subsequent formation of CCC. The study also shows that coupling of the alloy to platinum during the bromate pretreatment increases the corrosion resistance of the subsequently formed CCC by over an order of magnitude due to reduction in surface copper content. Adsorption of chromate ion on the passive oxide film formed on the metal surface was observed to induce fixed negative charges that inhibit chloride ingress on planar surfaces. While deprotonation of the aluminum hydroxide film by chromate was

  14. Treatment of conversion disorder. A clinical and holistic approach.

    PubMed

    Tocchio, Sandra L

    2009-08-01

    Conversion disorder is rare, but when it affects a young woman on the verge of adulthood, it can be devastating. The intent of this article is to encourage others by describing the success that psychiatry and alternative medicine can offer to patients with conversion disorder and to emphasize the value of nursing as a part of that team. This article will explore the attitude change in both staff and patient that was needed to achieve the ultimate goal of wellness.

  15. Development of a technique to prevent radiation damage of chromate conversion coatings during X-ray photoelectron spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Chidambaram, Devicharan; Halada, Gary P.; Clayton, Clive R.

    2001-09-01

    Photoreduction of hydrated sodium dichromate in the presence of carbon compounds has been studied by X-ray photoelectron spectroscopy (XPS). XPS results show that sodium dichromate also undergoes thermal breakdown during analysis. The photochemical and thermal reduction appears to be prevented by cooling with liquid nitrogen and using hydrocarbon-free vacuum pumping conditions. A model for the photoreduction of dichromate has been put forward based on an earlier photoreduction model developed by this group. Using the insight gained from this work, chromium spectra obtained from XPS of chromate conversion coatings (CCCs) on AA2024-T3 aluminum alloy have for the first time been fitted with six species of chromium compounds. The Cr 2p spectra have been critically examined for photoreduction of the hexavalent species: tetravalent and trivalent decomposition products have been identified. To explain the observed photochemical breakdown in CCCs even when performed under clean pumping conditions and liquid nitrogen cooling, its has been verified that the reduction is partly due to the cyanide species present in the CCCs. Cooling with liquid nitrogen prevents the adsorbed water on the coating from reacting with Cr(IV) to form trivalent species as the water molecules are immobilized and kinetics are slowed. As the Cr(VI)/Cr(III) ratio is critical to the performance of the CCC, and its accurate determination by XPS has not formerly been possible due to the photoreduction of Cr(VI) to Cr(III), we present a reliable method by which XPS can be used in characterization of chromate conversion coatings.

  16. Behavioural treatment of a food refusal conversion disorder in a mentally retarded adult.

    PubMed

    Weinman, B; Haydon, S; Sapan, J

    1990-12-01

    A 31-year-old woman with mental retardation who demonstrated total food refusal as the symptom of a conversion disorder was successfully treated with behavioural management techniques. The treatment utilized a shaping paradigm combined with relaxation procedures. The results supported the hypothesis that conversion disorder symptoms are maintained through their consequences, and the efficacy of behavioural treatments for those disorders.

  17. Excimer surface treatment to enhance bonding in coated steels

    NASA Astrophysics Data System (ADS)

    Mueller, Robert E.; Olfert, M.; Duley, Walter W.; North, T.; Hood, J.; Sakai, D.

    1996-04-01

    Zinc coated sheet steel in the form of temper rolled galvanize and galvanneal are used extensively in the automotive industry. Through a process of excimer laser surface treatment, we have succeeded in significantly enhancing the adhesion characteristics of these coated steels. The laser treatment is performed by scanning focused excimer laser radiation in a raster pattern over the surface to be bonded. Adhesion tests have been carried out in the form of T peel tests, using either a hot melt nylon resin or an epoxy as the adhesive. An increase in bond strength was observed over a substantial range of surface treatment conditions. The largest improvement observed was more than a factor of three greater than for untreated surfaces. With the improved surface condition, the bond strength became limited by the cohesive strength of the adhesive. The physical structure and chemical composition of the parent and excimer treated surfaces have been examined using scanning electron microscopy and X-ray photoelectron spectroscopy to determine the nature and extent of the changes caused by the surface treatment. The effects of the observed changes on the bonding performance will be discussed. Surfaces have been processed under an inert atmosphere to isolate the effects of physical surface modification and surface oxidation. An attempt will be made to correlate the surface changes with the bonding characteristics and thereby indicate which changes are most beneficial. The ultimate goal is to optimize the surface condition for bonding and maximize the process rate.

  18. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete.

    PubMed

    Simescu, Florica; Idrissi, Hassane

    2008-12-01

    We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca10(PO4)6(OH)2. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  19. Corrosion Behavior of Cerium-Based Conversion Coatings on Magnesium Alloys Exposed to Ambient Conditions

    NASA Astrophysics Data System (ADS)

    Castano, Carlos E.; Maddela, Surender; O'Keefe, Matthew J.

    Exposure of CeCCs on AZ31B and AZ91D Mg alloys to ambient sunlight, temperature, and humidity was done to determine the effect on corrosion resistance. It was found that the CeCCs changed from pale yellow to almost translucent after 24 hours of sunlight exposure. The effect of the solar electromagnetic radiation on the morphological, chemical and optical properties of these coatings was investigated using SEM and UV-Vis characterization techniques. In addition, the corrosion performance of CeCCs before and after ambient exposure was studied by ASTM B117 neutral spray testing and electrochemical polarization measurements. In general, the changes in appearance did not adversely affect the corrosion performance of the coatings.

  20. Protective coatings of metal surfaces by cold plasma treatment

    NASA Technical Reports Server (NTRS)

    Manory, R.; Grill, A.

    1985-01-01

    The cold plasma techniques for deposition of various types of protective coatings are reviewed. The main advantage of these techniques for deposition of ceramic films is the lower process temperature, which enables heat treating of the metal prior to deposition. In the field of surface hardening of steel, significant reduction of treatment time and energy consumption were obtained. A simple model for the plasma - surface reactions in a cold plasma system is presented, and the plasma deposition techniques are discussed in view of this model.

  1. Treatment off vulvovaginal candidal infection with miconazole-coated tampons.

    PubMed Central

    Bergstein, N A

    1980-01-01

    In an evaluation of three different treatment regimens miconazole-coated tampons proved to be effective for the relief of vulvovaginal candidal infection. A mycological and clinical cure rate of about 93% was achieved in patients treated with one tampon twice daily (up to a total of 15 tampons); 61% of patients were mycologically cured with a regimen of one tampon daily for only five days. Reinfection rates were less than 4% with all three regimens. The tampons were well accepted by all the patients. PMID:7470219

  2. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  3. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  4. Chromium-free conversion coatings based on inorganic salts (Zr/Ti/Mn/Mo) for aluminum alloys used in aircraft applications

    NASA Astrophysics Data System (ADS)

    Santa Coloma, P.; Izagirre, U.; Belaustegi, Y.; Jorcin, J. B.; Cano, F. J.; Lapeña, N.

    2015-08-01

    Novel chromium-free conversion coatings based on Zr/Ti/Mn/Mo compounds were developed at a pilot scale to improve the corrosion resistance of the AA2024-T3 and AA7075-T6 aluminum alloys for aircraft applications. The influence of the presence of Zr and Ti in the Zr/Ti/Mn/Mo conversion bath's formulation on the corrosion resistance of the coated alloys was investigated. The corrosion resistance provided by the conversion coatings was evaluated by salt spray exposure and potentiodynamic sweeps. Optical and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) and atomic force microscopy (AFM) operating in the Kelvin Probe mode (SKPFM) were used to provide microstructural information of the coated samples that achieved the best results in the corrosion tests. The salt spray test evidenced the higher corrosion resistance of the coated samples compared to the bare surfaces for both alloys. The potentiodynamic tests showed that the corrosion current density decreased for coated AA7075-T6 and AA2024-T3 alloys, which indicated an obvious improvement of the corrosion resistance with all the processes for both alloys. Although the corrosion resistance of the coated samples appeared to be higher for the alloy AA7075-T6 than for the alloy AA2024-T3, both alloys achieved the best corrosion protection with the coatings deposited from conversion bath formulations containing no titanium salts. The microscopy analysis on the coated AA7075-T6 samples revealed that a local deposition of Zr compounds and, possibly, an oxidation process occurred in the vicinity of the alloy's intermetallic particles. The amount of the Zr deposits at these locations increased with coating's formulations without Ti, which provided the best corrosion resistance. The Cr-free conversion coatings developed in this study for the AA7075-T6 and AA2024-T3 alloys do not meet yet the strict requirements of the aircraft industry. However, they significantly improved the corrosion

  5. Effluent treatment in the paint and coating industry. (Latest citations from World Surface Coatings abstracts). Published Search

    SciTech Connect

    1996-02-01

    The bibliography contains citations concerning the analysis and treatment of effluents from the coating industry. Filters used for solvent adsorption and recovery, activated carbon adsorption of paint fumes, hydrogen peroxide treatment of wastes, effluent heat recovery, and biological treatments are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  6. Protective conversion coating on mixed-metal substrates and methods thereof

    SciTech Connect

    O'Keefe, Matthew J.; Maddela, Surender

    2016-09-06

    Mixed-metal automotive vehicle bodies-in-white comprising ferrous metal surfaces, zinc surfaces, aluminum alloy surfaces, and magnesium alloy surfaces are cleaned and immersed in an aqueous bath comprising an adhesion promoter and an aqueous electrocoat bath (the adhesion promoter may be in the electrocoat bath. The adhesion promoter, which may be a cerium salt, is selected to react with each metal in the body surfaces to form an oxide layer that provides corrosion resistance for the surface and adherence for the deposited polymeric paint coating. The body is cathodic in the electrocoat deposition.

  7. Influence of previous tuberculosis treatment history on acid-fast bacilli smear and culture conversion.

    PubMed

    Lee, J; Lee, B J; Yoon, H I; Lee, C-T; Lee, J H

    2012-10-01

    A teaching hospital in the Republic of Korea, 2003-2009. To evaluate the effect of previous tuberculosis (TB) treatment history on sputum smear and culture conversion. Data, including sputum acid-fast bacilli (AFB) results at baseline and at weeks 2, 4, 8, 12, 16, 20 and 24, were collected from patients with AFB sputum smear-positive and culture-confirmed pulmonary TB. Patients with multidrug-resistant TB or those with poor adherence were excluded. AFB conversion was compared between patients with a previous history of anti-tuberculosis treatment and those without. The median age of the 208 patients was 49.0 years; 58.3% were male, while 43 (20.7%) had a history of previous anti-tuberculosis treatment. Patients with a history of previous treatment had significantly lower sputum smear-negative conversion at 2 weeks of treatment compared with patients without (70.0% vs. 44.8%, P = 0.005). However, the two groups did not differ in culture conversion and in smear conversion at 4, 8, 12, 16, 20 and 24 weeks of anti-tuberculosis treatment. Patients with a history of previous anti-tuberculosis treatment are more likely to have positive sputum AFB smear at 2 weeks of treatment. However, sputum culture conversion is not affected by previous treatment history.

  8. Formation of aluminide coatings by low-temperature heat treatment of Al coating electrodeposited from ionic liquid

    NASA Astrophysics Data System (ADS)

    Li, Yan; Xu, Bajin; Ling, Guoping; Liu, Kezhao; Chen, Chang'an; Zhang, Guikai

    2011-05-01

    In this study, we proposed a two-step approach to prepare aluminide coatings, namely electrodepositing Al from AlCl 3-1-ethyl-3-methyl-imidazolium chloride (AlCl 3-EMIC) ionic liquid at room temperature and subsequent heat treatment at low temperature. The adherence of the coating was checked by a simple mechanical scratch test. The surface and cross-sectional morphologies, phase structures and chemical compositions of the coatings after heat treatment were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX), respectively. The deposited Al coatings were in homogenous and controllable thickness with excellent adherence to the substrate. The coatings were brittle Fe 2Al 5 and FeAl 3 phase after 5 min heat treatment at 670 °C, which transformed into ductile FeAl phase after 16 h heat treatment. The advantages of this method in eliminating the brittle Fe 2Al 5, cracks and pores in the aluminide coatings were discussed.

  9. Coal conversion wastewater treatment by catalytic oxidation in supercritical water

    SciTech Connect

    Phillip E. Savage

    1999-10-20

    Wastewaters from coal-conversion processes contain phenolic compounds in appreciable concentrations. These compounds need to be removed so that the water can be discharged or re-used. Catalytic oxidation in supercritical water is one potential means of treating coal-conversion wastewaters, and this project examined the reactions of phenol over different heterogeneous oxidation catalysts in supercritical water. More specifically, the authors examined the oxidation of phenol over a commercial catalyst and over bulk MnO{sub 2}, bulk TiO{sub 2}, and CuO supported on Al{sub 2}O{sub 3}. They used phenol as the model pollutant because it is ubiquitous in coal-conversion wastewaters and there is a large database for non-catalytic supercritical water oxidation (SCWO) with which they can contrast results from catalytic SCWO. The overall objective of this research project is to obtain the reaction engineering information required to evaluate the utility of catalytic supercritical water oxidation for treating wastes arising from coal conversion processes. All four materials were active for catalytic supercritical water oxidation. Indeed, all four materials produced phenol conversions and CO{sub 2} yields in excess of those obtained from purely homogeneous, uncatalyzed oxidation reactions. The commercial catalyst was so active that the authors could not reliably measure reaction rates that were not limited by pore diffusion. Therefore, they performed experiments with bulk transition metal oxides. The bulk MnO{sub 2} and TiO{sub 2} catalysts enhance both the phenol disappearance and CO{sub 2} formation rates during SCWO. MnO{sub 2} does not affect the selectivity to CO{sub 2}, or to the phenol dimers at a given phenol conversion. However, the selectivities to CO{sub 2} are increased and the selectivities to phenol dimers are decreased in the presence of TiO{sub 2}, which are desirable trends for a catalytic SCWO process. The role of the catalyst appears to be accelerating the

  10. COAL CONVERSION WASTEWATER TREATMENT BY CATALYTIC OXIDATION IN SUPERCRITICAL WATER

    SciTech Connect

    Phillip E. Savage

    1999-10-18

    Wastewaters from coal-conversion processes contain phenolic compounds in appreciable concentrations. These compounds need to be removed so that the water can be discharged or re-used. Catalytic oxidation in supercritical water is one potential means of treating coal-conversion wastewaters, and this project examined the reactions of phenol over different heterogeneous oxidation catalysts in supercritical water. More specifically, we examined the oxidation of phenol over a commercial catalyst and over bulk MnO{sub 2}, bulk TiO{sub 2}, and CuO supported on Al{sub 2} O{sub 3}. We used phenol as the model pollutant because it is ubiquitous in coal-conversion wastewaters and there is a large database for non-catalytic supercritical water oxidation (SCWO) with which we can contrast results from catalytic SCWO. The overall objective of this research project is to obtain the reaction engineering information required to evaluate the utility of catalytic supercritical water oxidation for treating wastes arising from coal conversion processes. All four materials were active for catalytic supercritical water oxidation. Indeed, all four materials produced phenol conversions and CO{sub 2} yields in excess of those obtained from purely homogeneous, uncatalyzed oxidation reactions. The commercial catalyst was so active that we could not reliably measure reaction rates that were not limited by pore diffusion. Therefore, we performed experiments with bulk transition metal oxides. The bulk MnO{sub 2} and TiO{sub 2} catalysts enhance both the phenol disappearance and CO{sub 2} formation rates during SCWO. MnO{sub 2} does not affect the selectivity to CO{sub 2}, or to the phenol dimers at a given phenol conversion. However, the selectivities to CO{sub 2} are increased and the selectivities to phenol dimers are decreased in the presence of TiO{sub 2} , which are desirable trends for a catalytic SCWO process. The role of the catalyst appears to be accelerating the rate of formation of

  11. Treatment of gas from an in situ conversion process

    DOEpatents

    Diaz, Zaida [Katy, TX; Del Paggio, Alan Anthony [Spring, TX; Nair, Vijay [Katy, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX

    2011-12-06

    A method of producing methane is described. The method includes providing formation fluid from a subsurface in situ conversion process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. At least the olefins in the first gas stream are contacted with a hydrogen source in the presence of one or more catalysts and steam to produce a second gas stream. The second gas stream is contacted with a hydrogen source in the presence of one or more additional catalysts to produce a third gas stream. The third gas stream includes methane.

  12. Characterization and dissolution behavior of sputtered calcium phosphate coatings after different postdeposition heat treatment temperatures.

    PubMed

    Yang, Y; Agrawal, C M; Kim, K H; Martin, H; Schulz, K; Bumgardner, I D; Ong, J L

    2003-01-01

    There is a lack of correlation between specific properties of hydroxyapatite coating surfaces, osseointegration processes, and implant success. The aim of this study was to evaluate the relationship between well-characterized structural and chemical properties of radio-frequency sputtered calcium phosphate (CaP) coatings and their dissolution behavior. Sputtered CaP coatings were evaluated as-sputtered (non-heat treated) or after 1 hour of postsputter heat treatments at 400 degrees C or 600 degrees C. All coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and contact angle measurement. The dissolution behavior of CaP coatings in the presence and absence of proteins was also investigated. It was observed from this study that as-sputtered CaP coatings were amorphous. The 400 degrees C heat-treated CaP coatings exhibited low crystallinity (1.9% +/- 0.4%), whereas the 600 degrees C heat-treated CaP coatings were highly crystalline (67.0% +/- 2.4%). The increase of Ca/P ratio, PO4/HPO4 ratio, and the number of PO4 peaks were observed to be consistent with the increase in heating temperature and the degrees of coating crystallinity. Phosphorus ions released from CaP coatings decreased with the increase of crystallinity of CaP coatings. In addition, immersion of CaP coatings in media containing proteins resulted in an increase in P ions released as compared with coatings immersed in media without proteins. It was concluded that the degree of CaP coating crystallinity can be controlled by varying the postdeposition heat-treatment temperature. It was also concluded that, aside from coating crystallinity, dissolution and reprecipitation of the coatings can be controlled by knowing the presence of proteins in the media and PO4/HPO4 ratio within the coatings.

  13. In Vitro Corrosion and Cytocompatibility of ZK60 Magnesium Alloy Coated with Hydroxyapatite by a Simple Chemical Conversion Process for Orthopedic Applications

    PubMed Central

    Wang, Bing; Huang, Ping; Ou, Caiwen; Li, Kaikai; Yan, Biao; Lu, Wei

    2013-01-01

    Magnesium and its alloys—a new class of degradable metallic biomaterials—are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA) coating on ZK60 magnesium alloy substrates to mediate the rapid degradation of Mg while improving its cytocompatibility for orthopedic applications. A simple chemical conversion process was applied to prepare HA coating on ZK60 magnesium alloy. Surface morphology, elemental compositions, and crystal structures were characterized using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The corrosion properties of samples were investigated by immersion test and electrochemical test. Murine fibroblast L-929 cells were harvested and cultured with coated and non-coated ZK60 samples to determine cytocompatibility. The degradation results suggested that the HA coatings decreased the degradation of ZK60 alloy. No significant deterioration in compression strength was observed for all the uncoated and coated samples after 2 and 4 weeks’ immersion in simulated body fluid (SBF). Cytotoxicity test indicated that the coatings, especially HA coating, improved cytocompatibility of ZK60 alloy for L929 cells. PMID:24300096

  14. Phase transitions of hydroxyapatite coatings during post-heat treatment and their performances under ultrasonic tests.

    PubMed

    Tong, W; Li, X; Feng, J; Chen, J; Zhang, X

    2001-07-01

    Highly or completely crystalline hydroxyapatite (HA) coatings can be obtained by post-heat treatment. We have developed a high-temperature (490 degrees C) and a low-temperature (125 degrees C) heat treatment to improve the crystallinity of HA coatings. Both methods transform entirely the amorphous phase into crystalline HA. However, the microstructure of the coating is dependent on the post-heating method. Nanocrystalline HA is about half of the component of the low-temperature heated coating while highly crystalline HA dominates the high-temperature heated coating, as detected by X-ray diffraction. The effects of both methods on the disintegration of the coatings were tested by ultrasonic treatment. The high-temperature heated coatings exhibited poor integrity while the low-temperature heated coatings exhibited better integrity, possibly due to their different microstructure. SEM revealed that the coatings disintegrated via different mechanisms: the high-temperature heated coatings failed via crack initiation and propagation while the low-temperature heated coatings failed via pit formation and subsequent widening.

  15. Oxygen post-treatment of plastic surface coated with plasma polymerized silicon-containing monomers

    NASA Technical Reports Server (NTRS)

    Wydeven, T. J.; Hollanhan, J. R., Jr. (Inventor)

    1979-01-01

    The abrasion resistance of plastic surfaces coated with polymerized organosilanes can be significantly improved by post-treatment of the polymerized silane in an oxygen plasma. For optical purposes, the advantages of this post-treatment are developed with a transparent polycarbonate resin substrate coated with plasma polymerized vinyltrimethoxysilane.

  16. Superhydrophobic Post Treatment and Coating Extenders for Improved Asset Sustainability

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven; Montgomery, Eliza L.; Calle, Luz M.

    2015-01-01

    Launch structures, hardware, and ground support equipment, at NASA's John F. Kennedy Space Center in Florida, are exposed to a highly corrosive natural coastal marine environment. In addition, during launches, rocket exhaust deposition is also highly corrosive. Superhydrophobic coatings are being considered for additional corrosion protection on existing structures to enhance corrosion resistance and add an additional layer of protection against harsh environmental elements. These coatings have come into their own recently, and are now being investigated as corrosion protective coatings due to their water repelling capability. These coatings can be used on existing coatings, newly coated materials, or used on bare substrates. The coatings are not suitable for permanent corrosion protection, but can be used where additional corrosion control is desired or only when temporary corrosion control is needed, such as in hardware sitting on a launch pad for 30-45 days prior to a launch. In this study, superhydrophobic coatings were applied on various coated and uncoated substrates and exposed to the spaceport environment for various times up to 60 days. This paper highlights the current results of the superhydrophobic coatings performance evaluated by X-ray photoelectron spectroscopy, and contact angle measurements.

  17. Wastes to Resources: Appropriate Technologies for Sewage Treatment and Conversion.

    ERIC Educational Resources Information Center

    Anderson, Stephen P.

    Appropriate technology options for sewage management systems are explained in this four-chapter report. The use of appropriate technologies is advocated for its health, environmental, and economic benefits. Chapter 1 presents background information on sewage treatment in the United States and the key issues facing municipal sewage managers.…

  18. Corrosion protection of untreated AA-2024-T3 in chloride solution by a chromate conversion coating monitored with Raman spectroscopy

    SciTech Connect

    Zhao, J.; Frankel, G.; McCreery, R.L.

    1998-07-01

    The behavior of chromate conversion coatings (CCCs) on the aluminum aircraft alloy AA 2024-T3 was examined by several types of experiments, using Raman spectroscopy as a primary technique. First, Raman spectra of the CCC film made from a commercial process revealed a Raman feature characteristic of Cr(VI) which was distinct from Raman bands to an initially untreated alloy sample. The release of chromate from a CCC was demonstrated, as was redeposition of a chromate film on the fresh alloy surface. Formation of a Raman-observable Cr(VI)-containing deposit was more rapid in or near pits in the untreated alloy sample, and the deposit was spectroscopically very similar to the original CCC film. The initially untreated alloy became much less active toward corrosion after migration of chromate from the nearby CCC film, with the polarization resistance increasing by at least two orders of magnitude and the pitting potential increasing by 60 mV. The results clarify the mechanism of self-healing exhibited by CCC films, in which chromate species released from the CCC migrate to an actively corroding region and stop aluminum dissolution. The migrating chromate is selectively deposited at active corrosion sites, either by forming an insoluble Al/chromate precipitate or by adsorption by previously formed corrosion products.

  19. Electrophoretic painting on AZ31 Mg alloy pretreated in cerium conversion coating solutions prepared in ethanol-water mixtures

    NASA Astrophysics Data System (ADS)

    Van Phuong, Nguyen; Fazal, Basit Raza; Moon, Sungmo

    2017-01-01

    Electrophoretic painting (E-paint) was prepared on AZ31 Mg alloy samples pretreated in cerium conversion coating (CeCC) solutions with various ratios of ethanol and water mixture and its characteristics, adhesion and corrosion resistance were investigated. It was found that CeCC formed on AZ31 Mg alloy in a CeCC solution without ethanol was partly cracked structure and mainly consisted of Mg(OH)2/MgO, which exhibited weak adhesion with E-painting layer after water immersion test, and low corrosion resistance, as indicated by rapid formation of blisters and paint delamination during salt spray test. The addition of ethanol promoted the growth of a fine nano-crystalline CeO2 layer over the entire substrate surface. The E-paint on AZ31 pretreated in the CeCC solutions with addition of ethanol showed also improved corrosion resistance, as represented by the delayed time for paint delamination and blister formation. The E-paint layers on the CeCC layers formed in solutions containing 50-80 vol% ethanol showed stronger adhesion and better corrosion resistance than those formed on the samples treated in a non-ethanol containing CeCC solution.

  20. Surface treatments and edible coatings in food preservation

    USDA-ARS?s Scientific Manuscript database

    The use of synthetic and natural waxes and resins to coat fresh fruits and vegetables has been researched and practiced in the United States, the United Kingdom and Australia since the 1930s. Development of edible coatings for use on meat products was fist reported in the late 1950s. Currently, ed...

  1. Induction heat treatment and technique of bioceramic coatings production on medical titanium alloys

    NASA Astrophysics Data System (ADS)

    Fomin, Aleksandr A.; Rodionov, Igor V.; Fomina, Marina A.; Poshivalova, Elena Y.; Krasnikov, Aleksandr V.; Petrova, Natalia N.; Zakharevich, Andrey M.; Skaptsov, Alexander A.; Gribov, Andrey N.; Atkin, Vsevolod S.

    2015-03-01

    Prospective composite bioceramic titania coatings were obtained on intraosseous implants fabricated from medical titanium alloy VT16 (Ti-2.5Al-5Mo-5V). Consistency changes of morphological characteristics, physico-mechanical properties and biocompatibility of experimental titanium implant coatings obtained by oxidation during induction heat treatment are defined. Technological recommendations for obtaining bioceramic coatings with extremely high strength on titanium items surface are given.

  2. Facile synthesis of superhydrophobic surface of ZnO nanoflakes: chemical coating and UV-induced wettability conversion.

    PubMed

    Yao, Lujun; Zheng, Maojun; Li, Changli; Ma, Li; Shen, Wenzhong

    2012-04-13

    This work reports an oriented growth process of two-dimensional (2D) ZnO nanoflakes on aluminum substrate through a low temperature hydrothermal technique and proposes the preliminary growth mechanism. A bionic superhydrophobic surface with excellent corrosion protection over a wide pH range in both acidic and alkaline solutions was constructed by a chemical coating treatment with stearic acid (SA) molecules on ZnO nanoflakes. It is found that the superhydrophobic surface of ZnO nanoflake arrays shows a maximum water contact angle (CA) of 157° and a low sliding angle of 8°, and it can be reversibly switched to its initial superhydrophilic state under ultraviolet (UV) irradiation, which is due to the UV-induced decomposition of the coated SA molecules. This study is significant for simple and inexpensive building of large-scale 2D ZnO nanoflake arrays with special wettability which can extend the applications of ZnO films to many other important fields.

  3. Facile synthesis of superhydrophobic surface of ZnO nanoflakes: chemical coating and UV-induced wettability conversion

    PubMed Central

    2012-01-01

    This work reports an oriented growth process of two-dimensional (2D) ZnO nanoflakes on aluminum substrate through a low temperature hydrothermal technique and proposes the preliminary growth mechanism. A bionic superhydrophobic surface with excellent corrosion protection over a wide pH range in both acidic and alkaline solutions was constructed by a chemical coating treatment with stearic acid (SA) molecules on ZnO nanoflakes. It is found that the superhydrophobic surface of ZnO nanoflake arrays shows a maximum water contact angle (CA) of 157° and a low sliding angle of 8°, and it can be reversibly switched to its initial superhydrophilic state under ultraviolet (UV) irradiation, which is due to the UV-induced decomposition of the coated SA molecules. This study is significant for simple and inexpensive building of large-scale 2D ZnO nanoflake arrays with special wettability which can extend the applications of ZnO films to many other important fields. PMID:22500967

  4. Application of X-ray absorption fine structure method for the quantitative analysis of hexavalent chromium in chromate conversion coating and plastic.

    PubMed

    Oki, Mitsuhiro; Morimoto, Sayaka; Muramatsu, Miho; Yoshiki, Masahiko; Takenaka, Miyuki

    2014-01-01

    The X-ray absorption fine structure method was applied for the quantitative analysis of hexavalent Cr in electronic products. The pre-edge peak intensity of the Cr K-edge increased according to the hexavalent Cr amount, and the hexavalent Cr ratio was calculated quantitatively by using the intensity. By combining with inductively coupled plasma atomic emission spectroscopy measurement results that gave the total Cr amount, the absolute amount of hexavalent Cr in chromate conversion coating and plastic samples could be evaluated. The results obtained by this method were in good agreement with those obtained by the chemical analysis method. This method can be successfully applied for the determination of hexavalent Cr amount in electronic products such as chromate conversion coating and plastic.

  5. Effects of annealing heat treatment on the corrosion resistance of Zn/Mg/Zn multilayer coatings

    NASA Astrophysics Data System (ADS)

    Bae, KiTae; La, JoungHyun; Lee, InGyu; Lee, SangYul; Nam, KyungHoon

    2017-05-01

    Zn coatings alloyed with magnesium offer superior corrosion resistance compared to pure Zn or other Zn-based alloy coatings. In this study, Zn/Mg/Zn multilayer coatings with various Mg layer thicknesses were synthesized using an unbalanced magnetron sputtering process and were annealed to form Zn-Mg intermetallic phases. The effects of the annealing heat treatment on the corrosion resistance of the Zn/Mg/Zn multilayer coatings were evaluated using electrochemical measurements. The extensive diffusion of magnesium species into the upper and lower zinc layer from the magnesium layer in the middle of the coating was observed after the heat treatment. This phenomenon caused (a) the porous microstructure to transition into a dense structure and (b) the formation of a MgZn2 intermetallic phase. The results of the electrochemical measurements demonstrated that the heat treated Zn/Mg/Zn multilayer coatings possessed higher levels of corrosion resistance than the non-heat treated coatings. A Zn/Mg/Zn multilayer coating with MgZn2 and (Zn) phases showed the best corrosion resistance among the heat treated coatings, which could be attributed to the reduced galvanic corrosion effects due to a small potential gradient between the MgZn2 and zinc.

  6. The effect of laser treatment of WC-Co coatings on their failure under thermal cycling

    NASA Astrophysics Data System (ADS)

    Kasterov, Artur; Shugurov, Artur; Kazachenok, Marina; Panin, Alexey; Cheng, Chin-Hsiang; Chang, I.-Ling

    2016-11-01

    The given paper studies the effect of surface laser treatment of WC-Co coatings on their surface morphology, phase composition and thermal cycling behavior. The coatings were sprayed on stainless steel substrates with the use of a high velocity oxy fuel spraying process. Application of the scanning electron microscopy and X-ray diffraction showed that re-melting of the coating surface layer during laser treatment induced changes in its phase composition as well as the formation of regular rows of globular asperities on the coating surface. The latter resulted in a sharp increase in thermal shock resistance of the laser treated WC-Co coatings under water quench tests; its underlying mechanism are proposed and discussed in the paper.

  7. Heat treatments modify the tribological properties of nickel boron coatings.

    PubMed

    Gilley, Kevin L; Nino, Juan C; Riddle, Yancy W; Hahn, David W; Perry, Scott S

    2012-06-27

    The effects of annealing temperature on the tribological properties of electroless nickel-boron coatings have been investigated. The coatings were annealed in a tube furnace under a flow (0.0094 N m(3)/min) of oxygen gas at temperatures of 250, 400, 550, and 700 °C for 3 h. Using scanning electron microscopy, images of the annealed coatings documented changes in surface morphology. From this it was seen that the higher annealing temperatures produced marked changes, moving from the nodular structure of nickel-boron coatings to a flaked surface morphology. The chemical effect of the annealing temperature was studied via X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The XPS data indicated that after annealing at the temperatures of 550 and 700 °C, an accumulation of boron oxide species could be seen at the surface as well as a complete loss of nickel signal. An analysis of Raman spectra collected across the surface further identified the predominant species to be boric acid. The tribological response of the coatings was studied with a pin-on-disk tribometer with 440C stainless steel balls run against the coatings in ambient air. It was seen that the as received sample and the sample annealed at 250 °C samples exhibited modest friction properties, while the 400 °C sample had increased friction due to wear debris from the ball. The 550 and 700 °C samples showed remarkably low friction coefficients between 0.06 and 0.08, attributable to the presence of boric acid. The wear tracks were analyzed using scanning white light interferometry and from this data wear rates were obtained for the coatings ranging from 10(-8) to 10(-7) mm(3)/Nm.

  8. Behavioral Treatment of Conversion Disorder in Adolescence: A Case Example of Globus Hystericus.

    ERIC Educational Resources Information Center

    Donohue, Brad; Thevenin, Deborah M.; Runyon, Melissa K.

    1997-01-01

    Using a case study, evaluates the efficacy of a cognitive-behavioral intervention for the treatment of a patient diagnosed with a conversion disorder characterized by a perceived lump in the throat and subsequent weight loss. Results indicate that the behavioral therapy procedures contributed to increased weight and improved eating behavior. (RJM)

  9. Angioplasty with drug coated balloons for the treatment of infrainguinal peripheral artery disease.

    PubMed

    Werner, Martin

    2016-09-01

    Restenosis or re-occlusion after femoropopliteal angioplasty or stent implantation is the main limitation of endovascular treatment strategies for peripheral artery disease. Within the last years, balloon catheters with anti-proliferative drug coating on the balloon surface have shown to be associated with higher patency rates compared to plain balloon angioplasty. Thus, drug-coated balloons were gradually adopted in many interventional centres for the treatment of femoropopliteal obstructions. The current review summarises the existing evidence for drug-coated balloons in the infrainguinal vessels and their indication in special lesion cohorts.

  10. Use of plasma sprayed coatings as surface treatments for aluminum adherends

    SciTech Connect

    Davis, G.D.; Whisnant, P.L.; Groff, G.B.

    1996-12-31

    Surface treatments for metal adherends prior to adhesive bonding typically use chromates and/or strong acids and bases. Such materials are hazardous to personnel and harmful to the environment following disposal. To reduce release of these substances into the environment and lower disposal costs, plasma spray treatments are being developed as surface treatments for aluminum adherends. These treatments eliminate liquid and gaseous wastes and provide bond strength and durability comparable to that provided by the conventional chemical treatments. They have other potential advantages of being more suited for repair/refurbishment and less sensitive to metallurgical differences from alloy to alloy. Plasma sprayed coatings are used in a variety of applications where a coating tailored for specific properties is needed that may or may not be chemically or structurally similar to the base substrate. Plasma spraying has been shown to provide excellent high-temperature bond performance with titanium (unlike conventional oxidation treatments) and durability approaching that of phosphoric acid anodization for aluminum. Success has also been reported using other coatings on aluminum, titanium, and steel. Plasma spraying has the important advantage of versatility. A wide range of coatings (metals, ceramics, and polymers) can be deposited onto an equally wide range of substrates, and the coating properties can be optimized for a given application, independent of the substrate. Because of this versatility, plasma-sprayed coatings have been used for wear resistance, thermal barriers, EMI/RF shielding, corrosion resistance, slip/slide resistance, and biocompatibility in addition to adhesion.

  11. Coating compositions and method for the treatment of metal surfaces

    SciTech Connect

    Das, N.; Stastny, P.M.

    1984-09-11

    An aqeuous acidic composition provides improved coating for aluminum. The composition comprises from about 10 to about 150 ppm zirconium, from about 20 to about 250 ppm fluoride, from 30 to about 125 ppm tannin, from about about 15 to about 100 ppm phosphate and from about 5 to about 50 ppm zinc, said coating solution having a tannin to phosphate ratio in the range of at least about 1:1 to about 2:1 and a pH in the range of about 2.3 to about 2.95.

  12. The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers

    SciTech Connect

    Mamum, Md Abdullah A.; Elmustafa, Abdelmageed A,; Stutzman, Marcy L.; Adderley, Philip A.; Poelker, Matthew

    2014-03-01

    The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

  13. Dose Schedule and Enhanced Conversational Recast Treatment for Children With Specific Language Impairment

    PubMed Central

    2016-01-01

    Purpose Dosage has been identified as an important element of treatment that may affect treatment efficacy. The purpose of this study was to examine the role of dose schedule for treatment of grammatical morphology deficits in children with specific language impairment (SLI). Method Sixteen 4-to-5-year-old children with SLI participated in a 5-week intervention consisting of equivalent daily Enhanced Conversational Recast treatment (Plante et al., 2014) targeting grammatical morphology. Half of the children received treatment in one 30-min session (massed condition). Half received treatment in three 10-min sessions (spaced condition) within one 4-hr period. Progress was assessed 3 times weekly by probing a child's use of his or her treatment morpheme and untreated morpheme (a maturational control) in untreated contexts. Results Pre- to posttreatment morpheme usage differed significantly for children regardless of dosage condition, and pre to post usage of an untreated morpheme was unchanged, demonstrating overall treatment efficacy. There were no differences in treatment effects for the massed and spaced conditions. Conclusions The study adds to evidence that Enhanced Conversational Recast can produce positive results in a short period of time for children with SLI. Furthermore, clinicians may have some flexibility in terms of the dose schedule they use to deliver this treatment in an evidence-based manner. PMID:27701629

  14. Laser surface heat treatment of electroless Ni-P-SiC coating on Al356 alloy

    NASA Astrophysics Data System (ADS)

    Hashemi, Sayed Hamid; Shoja-Razavi, Reza

    2016-11-01

    Electroless Ni-P-SiC coatings are recognized for their hardness and wear resistance. In the present study, electroless Ni-P coatings containing SiC particles were co-deposited on Al356 substrate. Laser surface heat treatment was performed using 700 W Nd:YAG pulsed laser. Effects of different laser operating parameters, such as laser scan rate, laser average power and defocusing distance on microstructures were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The results of microstructural characterization indicated that the laser treatment under different operating conditions produced composite coating contained nanocrystallined Ni-based matrix with SiC particles Ni3P, Ni12P5, Ni5P2, Ni8P3 precipitates. The microhardness measurements showed that the hardness of the coating was increased up to 60%, due to laser heat treatment, without effect on base metal.

  15. Plasma treatment of thin film coated with graphene flakes for the reduction of sheet resistance.

    PubMed

    Kim, Sung Hee; Oh, Jong Sik; Kim, Kyong Nam; Seo, Jin Seok; Jeon, Min Hwan; Yang, Kyung Chae; Yeom, Geun Young

    2013-12-01

    We investigated the effects of plasma treatment on the sheet resistance of thin films spray-coated with graphene flakes on polyethylene terephthalate (PET) substrates. Thin films coated with graphene flakes show high sheet resistance due to defects within graphene edges, domains, and residual oxygen content. Cl2 plasma treatment led to decreased sheet resistance when treatment time was increased, but when thin films were treated for too long the sheet resistance increased again. Optimum treatment time was related to film thickness. The reduction of sheet resistance may be explained by the donation of holes due to forming pi-type covalent bonds of Cl with carbon atoms on graphene surfaces, or by C--Cl bonding at the sites of graphene defects. However, due to radiation damage caused by plasma treatment, sheet resistance increased with increased treatment time. We found that the sheet resistance of PET film coated with graphene flakes could be decreased by 50% under optimum conditions.

  16. Inhibition of pitting corrosion on aluminum alloy 2024-T3: Effect of soluble chromate additions vs. chromate conversion coating

    SciTech Connect

    Ilevbare, G.O.; Scully, J.R.; Yuan, J.; Kelly, R.G.

    2000-03-01

    Pitting potentials (E{sub pit}) of aluminum alloy (AA) 2024-T3 (UNS A92024) were improved with additions of 0.01 M sodium chromate (Na{sub 2}CrO{sub 4}, pH 8) and 0.0062 M Na{sub 2}Cro{sub 4} + 0.0038 M chromic acid (H{sub 2}CrO{sub 4}, pH 6) additions to 0.1 M sodium sulfate (Na{sub 2}SO{sub 4}) + 0.005 M sodium chloride (NaCl, pH 6) after 2-h periods at open-circuit potential (OCP). Chromate conversion coatings (CCC) on AA 2024-T3 also improved E{sub pit} determined in fast potentiodynamic scans without periods at OCP. These tests were designed to minimize chromate leaching and long-range transport of chromate. The OCP of CCC AA 2024-T3, Al{sub 2}Cu, Al{sub 2}CuMg, 99.999% Cu, and 99.998% Al were not changed significantly in 0.1 M Na{sub 2}SO{sub 4} + 0.005 M NaCl. Moreover, the OCP of AA 2024-T3, Al{sub 2}Cu, Al{sub 2}CuMg, and 99.999% Cu were not changed significantly in 0.1 M Na{sub 2}SO{sub 4} + 0.005 M NaCl with the addition of 0.01 M soluble chromate at pH 6 and pH 8. The mass transport limiting current density for O{sub 2} reduction also was not altered significantly by CCC or soluble chromate additions. Consequently, if the AA 2024-T3 matrix were polarized locally to the measured OCP of the intermetallics or replaced copper, inhibition of stable pitting on AA 2024-T3 is more likely to result form suppressed pit stabilization (in 0.1 M Na{sub 2}SO{sub 4} + 0.005 M NaCl with the addition of chromate at pH 6 or pH 8, or with CCC) than from eliminating two aspects associated with the potency of local galvanic couples (e.g., OCP of cathode sites and their oxygen reduction reaction kinetics [ORR]).

  17. Self-healing Li-Al layered double hydroxide conversion coating modified with aspartic acid for 6N01 Al alloy

    NASA Astrophysics Data System (ADS)

    Zhang, Caixia; Luo, Xiaohu; Pan, Xinyu; Liao, Liying; Wu, Xiaosong; Liu, Yali

    2017-02-01

    A self-healing Li-Al layered double hydroxide conversion coating (LCC) modified with aspartic acid (ALCC) was prepared on 6N01 Al alloy for corrosion protection. Scanning electron microscopy (SEM) showed that a compact thin film has been successfully formed on the alloy. X-ray diffraction (XRD) and FT-IR spectra proved that species of aspartic acid anions were successfully intercalated into LCC. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and neutral salt spray (NSS) testing showed that the resultant ALCC could provide effective corrosion protection for the Al alloy. During immersion of the ALCC-coated alloy in 3.5% NaCl solution, new film was formed in the area of artificially introduced scratch, indicating its self-healing capability. XPS results demonstrated that Cl- anions exchange partial Asp anions according to the change content of element on conversion coating. From the above results, the possible mechanism via exchange/self-assembly was proposed to illustrate the phenomenon of self-healing.

  18. Effect of Heat Treatment on the Microstructure and Microhardness of Nanostructural Al2O3 Coatings

    NASA Astrophysics Data System (ADS)

    Kovaleva, M.; Tyurin, Yu.; Vasilik, N.; Kolisnichenko, O.; Prozorova, M.; Arseenko, M.; Sirota, V.; Pavlenko, I.

    2014-10-01

    Nanostructural Al2O3 coatings were formed on a steel substrate surface using a multichamber detonation sprayer. The Al2O3 coatings were characterized by a dense microstructure with porosity below 1% and hardness of 1300 ± 25 HV0.3. The transition layer between the coating and substrate was up to 15 μm thick, containing Fe-Al-type intermetallic compounds (FeAl3, Fe2Al5). Postdeposition heat treatment of the samples at 850 °C for 3 h was carried out in air and argon environments. The effect of heat treatment on the microstructure and microhardness of the Al2O3 coatings was investigated by optical microscopy, scanning and transmission electron microscopy, scanning probe microscopy, x-ray phase analysis, and Vickers hardness testing. A positive impact of postcoating heat treatment on the coating microstructure and microhardness was observed. Heat treatment resulted in an increase in the coating hardness from 1300, to 1350 ± 25 HV0.3 and 1600 ± 25 HV0.3 after annealing in air and argon, respectively. Heat treatment in argon led to a more significant increase in the α-Al2O3 phase from 47 to 81%.

  19. Coated mesh photocatalytic reactor for air treatment applications: comparative study of support materials.

    PubMed

    Passalía, Claudio; Nocetti, Emanuel; Alfano, Orlando; Brandi, Rodolfo

    2017-03-01

    An experimental comparative study of different meshes as support materials for photocatalytic applications in gas phase is presented. The photocatalytic oxidation of dichloromethane in air was addressed employing different coated meshes in a laboratory-scale, continuous reactor. Two fiberglass meshes and a stainless steel mesh were studied regarding the catalyst load, adherence, and catalytic activity. Titanium dioxide photocatalyst was immobilized on the meshes by dip-coating cycles. Results indicate the feasibility of the dichloromethane elimination in the three cases. When the number of coating cycles was doubled, the achieved conversion levels were increased twofold for stainless steel and threefold for the fiberglass meshes. One of the fiberglass meshes (FG2) showed the highest reactivity per mass of catalyst and per catalytic surface area.

  20. Enhanced Erosion Protection of TWAS Coated Ti6Al4V Alloy Using Boride Bond Coat and Subsequent Laser Treatment

    NASA Astrophysics Data System (ADS)

    Mann, B. S.; Arya, Vivek; Pant, B. K.

    2011-08-01

    The material commonly used in low-pressure high-rating super critical/ultra super critical steam turbines as well as guide and moving blades of high speed aero compressors is Ti6Al4V alloy. These blades are severely affected owing to erosion which leads to drop in efficiency and increase in maintenance cost. This article deals with SHS 7170 coating on Ti6Al4V alloy using twin wire arc spraying (TWAS), enhancing its bonding by providing a thin bond coat and then treating with high-power diode laser (HPDL). Significant improvement in erosion resistance of this multilayer coating has been achieved because of the formation of fine-grained micro structure due to rapid heating and cooling rates associated with the laser surface treatment. After laser surface treatment, the fracture toughness of this multilayer has improved manifold. The water droplet and particulate erosion test results along with the damage mechanism are reported and discussed in this article.

  1. Deposition, Heat Treatment And Characterization of Two Layer Bioactive Coatings on Cylindrical PEEK

    PubMed Central

    Durham, John W.; Rabiei, Afsaneh

    2015-01-01

    Polyether ether ketone (PEEK) rods were coated via ion beam asssited deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength. PMID:27713592

  2. Deposition, Heat Treatment And Characterization of Two Layer Bioactive Coatings on Cylindrical PEEK.

    PubMed

    Durham, John W; Rabiei, Afsaneh

    2016-09-15

    Polyether ether ketone (PEEK) rods were coated via ion beam asssited deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength.

  3. Sealing Treatment of Aluminum Coating on S235 Steel with Thermal Diffusion of Zinc

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Zhang, Timing; Zhao, Weimin; Tang, Xiuyan

    2015-08-01

    The study introduced a thermal diffusion sealing treatment for arc-sprayed aluminum coating on S235 carbon steel. The sprayed aluminum-zinc duplex coating was heated to 420 °C, so that the low-melting-point zinc could diffuse into the pores of the aluminum coating. Optical microscope, microhardness, electron probe microanalysis, and x-ray diffraction were used to evaluate the sealing treatment. The calculated diffusion coefficient for zinc in the arc-sprayed aluminum coating was approximately 7.735 × 10-9 cm2/s. The diffused zinc could increase the compactness and microhardness of the aluminum coating. Nevertheless, adverse interface reactions could destroy the coating if the zinc made contact with the steel substrate. FeZn10 could form initially, and then the heat from the exothermic reactions between zinc and iron would initiate the reactions among iron, aluminum, and zinc. FeAl-Zn x , FeAl2-Zn x , and Fe2Al5-Zn x were generated following FeZn10. The defected structures were mainly composed of Fe2Al5-Zn x and FeZn10. All of these formed tough, brittle, intermetallics that have a negative effect on the coating performance. Thus, the contact between zinc and the steel substrate should be avoided, and the holding time should be restricted to 8.16 × 106 L 2 to prevent the generation of intermetallics.

  4. Effect of heat treatment duration on tribological behavior of electroless Ni-(high)P coatings

    NASA Astrophysics Data System (ADS)

    Biswas, A.; Das, S. K.; Sahoo, P.

    2016-09-01

    Electroless nickel coating occurs through an autocatalytic chemical reaction and without the aid of electricity. From tribological perspective, it is recommended due to its high hardness, wear resistance, lubricity and corrosion resistance properties. In this paper electroless Ni-P coatings with high phosphorous weight percentages are developed on mild steel (AISI 1040) substrates. The coatings are subjected to heat treatment at 300°C and 500°C for time durations up to 4 hours. The effect of heat treatment duration on the hardness as well as tribological properties is discussed in detail. Hardness is measured in a micro hardness tester while the tribological tests are carried out on a pin-on-disc tribotester. Wear is reported in the form of wear rates of the sample subjected to the test. As expected, heat treatment of electroless Ni-P coating results in enhancement in its hardness which in turn increases its wear resistance. The present study also finds that duration of heat treatment has quite an effect on the properties of the coating. Increase in heat treatment time in general results in increase in the hardness of the coating. Coefficient of friction is also found to be lesser for the samples heat treated for longer durations (4 hour). However, in case of wear, similar trend is not observed. Instead samples heat treated for 2 to 3 hour display better wear resistance compared to the same heat treated for 4 hour duration. The microstructure of the coating is also carried out to ensure about its proper development. From scanning electron microscopy (SEM), the coating is found to possess the conventional nodular structure while energy dispersive X-ray analysis (EDX) shows that the phosphorous content in the coating to be greater than 9%. This means that the current coating belongs to the high phosphorous category. From X-ray diffraction analysis (XRD), it is found that coating is amorphous in as-deposited condition but transforms into a crystalline structure with

  5. DMF as an Additive in a Two-Step Spin-Coating Method for 20% Conversion Efficiency in Perovskite Solar Cells.

    PubMed

    Wu, Jionghua; Xu, Xin; Zhao, Yanhong; Shi, Jiangjian; Xu, Yuzhuan; Luo, Yanhong; Li, Dongmei; Wu, Huijue; Meng, Qingbo

    2017-08-16

    DMF as an additive has been employed in FAI/MAI/IPA (FA= CH2(NH2)2, MA = CH3NH3, IPA = isopropanol) solution for a two-step multicycle spin-coating method in order to prepare high-quality FAxMA1-xPbI2.55Br0.45 perovskite films. Further investigation reveals that the existence of DMF in the FAI/MAI/IPA solution can facilitate perovskite conversion, improve the film morphology, and reduce crystal defects, thus enhancing charge-transfer efficiency. By optimization of the DMF amount and spin-coating cycles, compact, pinhole-free perovskite films are obtained. The nucleation mechanisms of perovskite films in our multicycle spin-coating process are suggested; that is, the introduction of DMF in the spin-coating FAI/MAI/IPA solution can lead to the formation of an amorphous phase PbX2-AI-DMSO-DMF (X = I, Br; A = FA, MA) instead of intermediate phase (MA)2Pb3I8·2DMSO. This amorphous phase, similar to that in the one-step method, can help FAI/MAI penetrate into the PbI2 framework to completely convert into the perovskite. As high as 20.1% power conversion efficiency (PCE) has been achieved with a steady-state PCE of 19.1%. Our work offers a simple repeatable method to prepare high-quality perovskite films for high-performance PSCs and also help further understand the perovskite-crystallization process.

  6. A Brief Historical Perspective on Dental Implants, Their Surface Coatings and Treatments

    PubMed Central

    Abraham, Celeste M

    2014-01-01

    This review highlights a brief, chronological sequence of the history of dental implants. This historical perspective begins with ancient civilizations and spotlights predominant dentists and their contributions to implant development through time. The physical, chemical and biologic properties of various dental implant surfaces and coatings are discussed, and specific surface treatments include an overview of machined implants, etched implants, and sand-blasted implants. Dental implant coatings such as hydroxyapatite, fluoride, and statin usage are further reviewed. PMID:24894638

  7. Launcher Roadmap for the CrVI Substitution of Surface Treatments. Screening of Trivalent-Chromium Conversion Solutions and First Promising Results for Repair Applications on Aluminium Alloys

    NASA Astrophysics Data System (ADS)

    Debout, Vincent; Pettier, Sophie

    2014-06-01

    Airbus Defence and Space, Space System is involved in a global roadmap for launchers in order to substitute hexavalent chromium (CrVI) and Cadmium in the current surface treatments on metallic structures.Within this framework, a screening of trivalent chromium (CrIII) conversion solutions for touch-up applications has been carried out since this step is crucial to perform local application or to repair minor damages on launcher structures but it leads to higher risks of exposure for the workers.Three commercial CrIII conversion solutions have been evaluated on high performance aluminum alloys such as AA2024 T3 and AA7175 T7351 that are often used as structural materials.This preliminary investigation highlights the effect of surface preparation, rinsing and conversion process on the final corrosion performance of conversion coatings (CCs). The results are also discussed in terms of visual aspect and adhesion with new Cr-free primers.Two operating sets of parameters are identified with promising results that represent the first steps towards the development of a new Cr-free touch-up process.

  8. Shortening Treatment in Adults with Noncavitary Tuberculosis and 2-Month Culture Conversion

    PubMed Central

    Johnson, John L.; Hadad, David Jamil; Dietze, Reynaldo; Noia Maciel, Ethel Leonor; Sewali, Barrett; Gitta, Phineas; Okwera, Alphonse; Mugerwa, Roy D.; Alcaneses, Mary Rose; Quelapio, Maria Imelda; Tupasi, Thelma E.; Horter, Libby; Debanne, Sara M.; Eisenach, Kathleen D.; Boom, W. Henry

    2009-01-01

    Rationale: Cavitary disease and delayed culture conversion have been associated with relapse. Combining patient characteristics and measures of bacteriologic response might allow treatment shortening with current drugs in some patients. Objectives: To assess whether treatment could be shortened from 6 to 4 months in patients with noncavitary tuberculosis whose sputum cultures converted to negative after 2 months. Methods: This study was a randomized, open-label equivalence trial. HIV-uninfected adults with noncavitary tuberculosis were treated daily with isoniazid, rifampin, pyrazinamide, and ethambutol for 2 months, followed by 2 months of isoniazid and rifampin. After 4 months, patients with drug-susceptible TB whose sputum cultures on solid media were negative after 8 weeks of treatment were randomly assigned to continue treatment for 2 more months or to stop treatment. Patients were followed for relapse for 30 months after beginning treatment. Measurements and Main Results: Enrollment was stopped by the safety monitoring committee after 394 patients were enrolled due to apparent increased risk for relapse in the 4-month arm. A total of 370 patients were eligible for per protocol analysis. Thirteen patients in the 4-month arm relapsed, compared with three subjects in the 6-month arm (7.0 vs. 1.6%; risk difference, 0.054; 95% confidence interval with Hauck-Anderson correction, 0.01–0.10). Conclusion: Shortening treatment from 6 to 4 months in adults with noncavitary disease and culture conversion after 2 months using current drugs resulted in a greater relapse rate. The combination of noncavitary disease and 2-month culture conversion was insufficient to identify patients with decreased risk for relapse. PMID:19542476

  9. Determination of CT-to-density conversion relationship for image-based treatment planning systems.

    PubMed

    Saw, Cheng B; Loper, Alphonse; Komanduri, Krishna; Combine, Tony; Huq, Saiful; Scicutella, Carol

    2005-01-01

    The implementation of tissue inhomogeneity correction in image-based treatment planning will improve the accuracy of radiation dose calculations for patients undergoing external-beam radiotherapy. Before the tissue inhomogeneity correction can be applied, the relationship between the computed tomography (CT) value and density must be established. This tissue characterization relationship allows the conversion of CT value in each voxel of the CT images into density for use in the dose calculations. This paper describes the proper procedure of establishing the CT value to density conversion relationship. A tissue characterization phantom with 17 inserts made of different materials was scanned using a GE Lightspeed Plus CT scanner (120 kVp). These images were then downloaded into the Eclipse and Pinnacle treatment planning systems. At the treatment planning workstation, the axial images were retrieved to determine the CT value of the inserts. A region of interest was drawn on the central portion of the insert and the mean CT value and its standard deviation were determined. The mean CT value was plotted against the density of the tissue inserts and fitted with bilinear equations. A new set of CT values vs. densities was generated from the bilinear equations and then entered into the treatment planning systems. The need to obtain CT values through the treatment planning system is very clear. The 2 treatment planning systems use different CT value ranges, one from -1024 to 3071 and the other from 0 to 4096. If the range is correct, it would result in inappropriate use of the conversion curve. In addition to the difference in the range of CT values, one treatment planning system uses physical density, while the other uses relative electron density.

  10. Conversion disorder: a case report of treatment with the Main Puteri, a Malay shamanastic healing ceremony.

    PubMed

    Razali, S M

    1999-12-01

    We report on the case of a 38-year-old Malay housewife diagnosed with conversion disorder. It was believed that 'evil spirits' caused her symptoms. The patient was eventually treated by the Main Puteri, a Malay shamanistic healing ceremony, after previous treatments failed. The patient improved on the third day of the performance, which was attributed to the departure of the spirits from her body. This case documents the potential benefits of indigenous psychotherapy.

  11. Robust antifogging antireflective coatings on polymer substrates by hydrochloric acid vapor treatment.

    PubMed

    Li, Tong; He, Junhui; Yao, Lin; Geng, Zhi

    2015-04-15

    Antireflective coatings on polymer substrates have received significant attention for their potential applications. In this paper, robust microporous antifogging antireflective coatings on polymer substrates were prepared from acid-catalyzed silica sol followed by hydrochloric acid vapor solidification at mild temperature below glass transition temperatures of common polymers. The coatings passed 3H pencil hardness test, sand flow test and water-drop test. They had excellent antireflective and antifogging properties. The maximum transmittance of coatings on PMMA substrates reached 100.0% (the maximum transmittance wavelength could be regulated) and average transmittance reached 99.0% in 400-800 nm. The advantage and mechanism of hydrochloric acid vapor solidification and mechanical strength enhancement of coatings are discussed in contrast to ammonia vapor treatment and air vapor treatment. The hydrochloric acid vapor treatment results in a dense integrated microporous film structure. Optical properties were characterized by a UV-Vis spectrophotometer. Surface wettability was studied by a contact angle/interface system. Surface morphologies and structures of coatings were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atom force microscopy (AFM).

  12. Thermal radiative properties: Coatings.

    NASA Technical Reports Server (NTRS)

    Touloukian, Y. S.; Dewitt, D. P.; Hernicz, R. S.

    1972-01-01

    This volume consists, for the most part, of a presentation of numerical data compiled over the years in a most comprehensive manner on coatings for all applications, in particular, thermal control. After a moderately detailed discussion of the theoretical nature of the thermal radiative properties of coatings, together with an overview of predictive procedures and recognized experimental techniques, extensive numerical data on the thermal radiative properties of pigmented, contact, and conversion coatings are presented. These data cover metallic and nonmetallic pigmented coatings, enamels, metallic and nonmetallic contact coatings, antireflection coatings, resin coatings, metallic black coatings, and anodized and oxidized conversion coatings.

  13. Multi-functional electrospun nanofibres for advances in tissue regeneration, energy conversion & storage, and water treatment.

    PubMed

    Peng, Shengjie; Jin, Guorui; Li, Linlin; Li, Kai; Srinivasan, Madhavi; Ramakrishna, Seeram; Chen, Jun

    2016-03-07

    Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment.

  14. Partial oxidation of TiN coating by hydrothermal treatment and ozone treatment to improve its osteoconductivity.

    PubMed

    Shi, Xingling; Xu, Lingli; Le, Thi Bang; Zhou, Guanghong; Zheng, Chuanbo; Tsuru, Kanji; Ishikawa, Kunio

    2016-02-01

    Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O3) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O3 treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100°C since higher temperatures would impair the hardness of TiN coating. By contrast, O3 treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O3 treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant.

  15. Coatings for rubber bonding and paint adhesion

    NASA Astrophysics Data System (ADS)

    Boulos, M. S.; Petschel, M.

    1997-08-01

    Conversion coatings form an important base for the adhesion of paint to metal substrates and for the bonding of rubber to metal parts. Four types of conversion coatings were assessed as base treatments for the bonding of rubber to steel and for the corrosion protection of metal substrates under paint: amorphous iron phosphate, heavy zinc phosphate, and three types of modified zinc phosphates that utilized one or more metal cations in addition to zinc. When applied, these conversion coatings formed a thin film over the metal substrate that was characterized by scanning electron microscopy, x-ray diffraction, and chemical methods. The performance of the coatings was assessed using physical methods such as dry adhesion, conical mandrel, impact, and stress adhesion for the rubber-bonded parts, and by corrosion resistance methods such as humidity, salt spray, and cyclic corrosion. Coating characterization and performance were correlated.

  16. Association between serum selenium level and conversion of bacteriological tests during antituberculosis treatment* **

    PubMed Central

    de Moraes, Milena Lima; Ramalho, Daniela Maria de Paula; Delogo, Karina Neves; Miranda, Pryscila Fernandes Campino; Mesquita, Eliene Denites Duarte; de Oliveira, Hedi Marinho de Melo Guedes; Ruffino-Netto, Antônio; de Almeida, Paulo César; Hauser-Davis, Rachel Ann; Campos, Reinaldo Calixto; Kritski, Afrânio Lineu; de Oliveira, Martha Maria

    2014-01-01

    Objective: To determine whether serum selenium levels are associated with the conversion of bacteriological tests in patients diagnosed with active pulmonary tuberculosis after eight weeks of standard treatment. Methods: We evaluated 35 healthy male controls and 35 male patients with pulmonary tuberculosis, the latter being evaluated at baseline, as well as at 30 and 60 days of antituberculosis treatment. For all participants, we measured anthropometric indices, as well as determining serum levels of albumin, C-reactive protein (CRP) and selenium. Because there are no reference values for the Brazilian population, we used the median of the serum selenium level of the controls as the cut-off point. At 30 and 60 days of antituberculosis treatment, we repeated the biochemical tests, as well as collecting sputum for smear microscopy and culture from the patients. Results: The mean age of the patients was 38.4 ± 11.4 years. Of the 35 patients, 25 (71%) described themselves as alcoholic; 20 (57.0%) were smokers; and 21 (60.0%) and 32 (91.4%) presented with muscle mass depletion as determined by measuring the triceps skinfold thickness and arm muscle area, respectively. Of 24 patients, 12 (39.2%) were classified as moderately or severely emaciated, and 15 (62.5%) had lost > 10% of their body weight by six months before diagnosis. At baseline, the tuberculosis group had lower serum selenium levels than did the control group. The conversion of bacteriological tests was associated with the CRP/albumin ratio and serum selenium levels 60 days after treatment initiation. Conclusions: Higher serum selenium levels after 60 days of treatment were associated with the conversion of bacteriological tests in pulmonary tuberculosis patients. PMID:25029650

  17. The treatment of uncoated and titanium nitride-coated abutments with different instruments.

    PubMed

    Mengel, Reiner; Meer, Cordula; Flores-de-Jacoby, Lavin

    2004-01-01

    The aim of this in vitro study of titanium abutments was to investigate the extent of treatment traces, the roughness depth, and the quantity of titanium or, in the case of coated abutments, titanium nitride (TiN) removed from the surface after treatment with various instruments. Eleven uncoated, mechanically smoothed abutments and 11 TiN-coated abutments were used. The abutments were treated with titanium, steel, and plastic curettes; a rubber cup; an ultrasonic scaler with a steel tip; and an air scaler and cleaning powder. There were two 2 x 2-mm test fields on each abutment; each was subjected to standardized treatment with an instrument. The untreated surfaces of each abutment served as controls. The roughness depth (Rz) and profile height of treated and untreated surfaces were measured with a profilometer; profile height served as a basis for determining the amount of substance removed by treatment. The treatment traces were analyzed by scanning electron microscopy and light microscopy. Both the ultrasonic scaler and the steel and titanium curettes left pronounced traces on the uncoated abutments and increased Rz. Substantial substance removal was recorded following the use of the ultrasonic scaler (17.57 +/- 2.87 microm) and the steel curettes (8.48 +/- 2.81 microm) on the uncoated abutments. In tests of the coated abutments, measurable substance removal (4.80 +/- 0.99 microm) and increased roughness depth were noted only with use of the steel curettes. The treatment traces left by the other instruments were distinctly less pronounced than on the uncoated abutments. Light microscopy revealed detachment of the TiN coating after use of the ultrasonic scaler, titanium curettes, and steel curettes. Slight to moderate treatment traces were recorded after use of the rubber cup; no substance removal was observed. On the TiN-coated abutments, only slight treatment traces, if any, were recorded, and there was no substance removal. A planing effect (ie, an Rz decrease

  18. Size effect of nanometer vacuum gap thermionic power conversion device with CsI coated graphite electrodes

    NASA Astrophysics Data System (ADS)

    Lee, Jeong Ik; Jeong, Yong Hoon; No, Hee-Cheon; Hannebauer, Rob; Yoo, Sang-Keun

    2009-11-01

    Cesium iodide (CsI) coated graphite is a good candidate for an electrode material of a thermionic power generation device due to its low work function. In this letter, a thermionic device with a nanometer-scale vacuum gap between a CsI coated graphite emitter and a collector will be investigated while considering various gap-size effects. It is shown that a nanometer scale gap-size not only affects electron transport but also photon transport, and that all of these effects must be taken into account when estimating the device's performance.

  19. Structure of electroexplosive TiC-Ni composite coatings on steel after electron-beam treatment

    NASA Astrophysics Data System (ADS)

    Romanov, D. A.; Goncharova, E. N.; Budovskikh, E. A.; Gromov, V. E.; Ivanov, Yu. F.; Teresov, A. D.; Kazimirov, S. A.

    2016-11-01

    The phase and elemental compositions of the surface layer in Hardox 450 steel after electroexplosive spraying of a TiC-Ni composite coating and subsequent irradiation by a submillisecond high-energy electron beam are studied by the methods of modern physical metallurgy. The electron-beam treatment conditions that result in the formation of dense surface layers having high luster and a submicrocrystalline structure based on titanium carbide and nickel are found. It is shown that electron-beam treatment of an electroexplosive coating performed under melting conditions leads to the formation of a homogeneous (in structure and concentration) surface layer.

  20. Selective Laser Treatment on Cold-Sprayed Titanium Coatings: Numerical Modeling and Experimental Analysis

    NASA Astrophysics Data System (ADS)

    Carlone, Pierpaolo; Astarita, Antonello; Rubino, Felice; Pasquino, Nicola; Aprea, Paolo

    2016-12-01

    In this paper, a selective laser post-deposition on pure grade II titanium coatings, cold-sprayed on AA2024-T3 sheets, was experimentally and numerically investigated. Morphological features, microstructure, and chemical composition of the treated zone were assessed by means of optical microscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry. Microhardness measurements were also carried out to evaluate the mechanical properties of the coating. A numerical model of the laser treatment was implemented and solved to simulate the process and discuss the experimental outcomes. Obtained results highlighted the key role played by heat input and dimensional features on the effectiveness of the treatment.

  1. Fabrication of strongly attached hydroxyapatite coating on titanium by hydrothermal treatment of Ti-Zn-PO4 coated titanium in CaCl 2 solution.

    PubMed

    Valanezhad, Alireza; Tsuru, Kanji; Ishikawa, Kunio

    2015-07-01

    Hydroxyapatite (HAp) coating was formed on zinc phosphate (Ti-Zn-PO4) coated Ti plates by hydrothermal treatment in CaCl2 solution at 200 °C for 12 h. Uniform surface coverage of the fabricated HAp coating was obtained by this method. SEM-EDX analysis of the adhesion test area showed that the presence of fractures only occurred in HAp crystals. On the other words cohesive fracture was seen in HAp coating layer formed on the Ti-Zn-PO4. The measured strength was around 42.3 ± 17 MPa. Rat bone marrow (RBM) mesenchymal stem cells were cultured and differentiation-induced on each sample (Ti plate, Ti-Zn-PO4 coated and HAp coated), and cell calcification properties were examined. Apparent differences in morphology and extension of the RBM cells were obtained, while the Ti-Zn-PO4 coated samples showed the highest cell number among all samples. After differentiation-induction, HAp coated samples showed the highest amount of alkaline phosphatase activity, and the highest level of cell calcification. Therefore, the hard tissue compatibility of Ti is improved by hydrothermally HAp coating of samples.

  2. Dual-enhanced photothermal conversion properties of reduced graphene oxide-coated gold superparticles for light-triggered acoustic and thermal theranostics.

    PubMed

    Lin, Li-Sen; Yang, Xiangyu; Niu, Gang; Song, Jibin; Yang, Huang-Hao; Chen, Xiaoyuan

    2016-01-28

    A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the plasmonic coupling of the self-assembled gold nanoparticles and the interaction between GSPs and rGO endow rGO-GSPs with enhanced photothermal conversion properties, allowing rGO-GSPs to be used for sensitive photoacoustic detection and efficient photothermal ablation of tumours in vivo. This study provides a facile approach to prepare colloidal superparticles-graphene hybrid nanostructures and will pave the way toward the design and optimization of photothermal nanomaterials with improved properties for theranostic applications.

  3. Dual-enhanced photothermal conversion properties of reduced graphene oxide-coated gold superparticles for light-triggered acoustic and thermal theranostics†

    PubMed Central

    Lin, Li-Sen; Yang, Xiangyu; Niu, Gang

    2017-01-01

    A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the plasmonic coupling of the self-assembled gold nanoparticles and the interaction between GSPs and rGO endow rGO-GSPs with enhanced photothermal conversion properties, allowing rGO-GSPs to be used for sensitive photoacoustic detection and efficient photothermal ablation of tumours in vivo. This study provides a facile approach to prepare colloidal superparticles–graphene hybrid nanostructures and will pave the way toward the design and optimization of photothermal nanomaterials with improved properties for theranostic applications. PMID:26726809

  4. Tuning Surface Chemistry of Polyetheretherketone by Gold Coating and Plasma Treatment.

    PubMed

    Novotná, Zdeňka; Rimpelová, Silvie; Juřík, Petr; Veselý, Martin; Kolská, Zdeňka; Hubáček, Tomáš; Borovec, Jakub; Švorčík, Václav

    2017-12-01

    Polyetheretherketone (PEEK) has good chemical and biomechanical properties that are excellent for biomedical applications. However, PEEK exhibits hydrophobic and other surface characteristics which cause limited cell adhesion. We have investigated the potential of Ar plasma treatment for the formation of a nanostructured PEEK surface in order to enhance cell adhesion. The specific aim of this study was to reveal the effect of the interface of plasma-treated and gold-coated PEEK matrices on adhesion and spreading of mouse embryonic fibroblasts. The surface characteristics (polarity, surface chemistry, and structure) before and after treatment were evaluated by various experimental techniques (gravimetry, goniometry, X-ray photoelectron spectroscopy (XPS), and electrokinetic analysis). Further, atomic force microscopy (AFM) was employed to examine PEEK surface morphology and roughness. The biological response of cells towards nanostructured PEEK was evaluated in terms of cell adhesion, spreading, and proliferation. Detailed cell morphology was evaluated by scanning electron microscopy (SEM). Compared to plasma treatment, gold coating improved PEEK wettability. The XPS method showed a decrease in the carbon concentration with increasing time of plasma treatment. Cell adhesion determined on the interface between plasma-treated and gold-coated PEEK matrices was directly proportional to the thickness of a gold layer on a sample. Our results suggest that plasma treatment in a combination with gold coating could be used in biomedical applications requiring enhanced cell adhesion.

  5. Tuning Surface Chemistry of Polyetheretherketone by Gold Coating and Plasma Treatment

    NASA Astrophysics Data System (ADS)

    Novotná, Zdeňka; Rimpelová, Silvie; Juřík, Petr; Veselý, Martin; Kolská, Zdeňka; Hubáček, Tomáš; Borovec, Jakub; Švorčík, Václav

    2017-06-01

    Polyetheretherketone (PEEK) has good chemical and biomechanical properties that are excellent for biomedical applications. However, PEEK exhibits hydrophobic and other surface characteristics which cause limited cell adhesion. We have investigated the potential of Ar plasma treatment for the formation of a nanostructured PEEK surface in order to enhance cell adhesion. The specific aim of this study was to reveal the effect of the interface of plasma-treated and gold-coated PEEK matrices on adhesion and spreading of mouse embryonic fibroblasts. The surface characteristics (polarity, surface chemistry, and structure) before and after treatment were evaluated by various experimental techniques (gravimetry, goniometry, X-ray photoelectron spectroscopy (XPS), and electrokinetic analysis). Further, atomic force microscopy (AFM) was employed to examine PEEK surface morphology and roughness. The biological response of cells towards nanostructured PEEK was evaluated in terms of cell adhesion, spreading, and proliferation. Detailed cell morphology was evaluated by scanning electron microscopy (SEM). Compared to plasma treatment, gold coating improved PEEK wettability. The XPS method showed a decrease in the carbon concentration with increasing time of plasma treatment. Cell adhesion determined on the interface between plasma-treated and gold-coated PEEK matrices was directly proportional to the thickness of a gold layer on a sample. Our results suggest that plasma treatment in a combination with gold coating could be used in biomedical applications requiring enhanced cell adhesion.

  6. RetCam II Fluorescein Angiography to Guide Treatment and Diagnosis of Coats Disease.

    PubMed

    Koozekanani, Dara D; Connor, Thomas B; Wirostko, William J

    2010-03-09

    Coats disease is a well-described clinical condition featuring peripheral leakage from telangiectatic vasculature, resulting in exudative retinal detachments and exudative deposits. It often affects pediatric patients, requiring examinations and treatments to be performed under anesthesia. It can be difficult to distinguish from retinoblastoma. The RetCam II is a wide-field fundus imaging system that can also obtain intraoperative fluorescein angiography. The case of a 5-year-old girl diagnosed with Coats disease is presented. She presented with an exudative detachment, a submacular nodule, and peripheral telangiectasis. An examination under anesthesia, including angiography, was performed. The angiograph revealed characteristic aneurysms as well as extensive areas of telangiectasis and ischemia not readily visible on examination. The angiogram allowed more diagnostic certainty and guided a more complete treatment than otherwise possible. We propose that fluorescein angiography with the RetCam II system can be a useful tool when examining and treating pediatric patients with Coats disease.

  7. Influence of the Conditions of Electrode Position and Heat Treatment on the Structure and Properties of Metallic Coatings

    NASA Astrophysics Data System (ADS)

    Kovenskiy, I. M.; Kulemina, A. A.

    2016-04-01

    Influence of electrodeposition conditions and heat treatment on the structure and properties of metallic coatings has been considered. It has been that at different values of overvoltage, metals crystallize with a cellular, subgrain or monoblock structure. The final formation of the structure occurs during annealing, in the process of which either polygonization or recrystallization develops in the coatings. Varying the conditions of electrodeposition and heat treatment allows obtaining coatings with functional characteristics for specific operating conditions.

  8. Graphene based anticorrosive coatings for Cr(VI) replacement.

    PubMed

    Aneja, Karanveer S; Bohm, Sivasambu; Khanna, A S; Bohm, H L Mallika

    2015-11-14

    Corrosion has been a perennial issue of concern for the steel industry. Chromate conversion coatings are well known pre-treatment coatings for steel but due to environmental concerns and legislations, their use has been restricted. The industrial community, pegged by these legislations, has been long demanding an economically viable and eco-friendly pre-treatment coating alternative, without having to compromise on the durability and corrosion performance of the overall coating system. The present study focuses on evaluation of graphene as an anticorrosive alternative to Cr(VI) based coatings. Graphene, produced by a high shear liquid exfoliation route, upon functionalisation, provides a conductive and nearly impermeable barrier coating. On electrochemical and coating performance evaluation of this coating system, a dramatic improvement in corrosion resistance is observed. The study confirms the environment friendly corrosion protection of steel using functionalised graphene coating.

  9. Graphene based anticorrosive coatings for Cr(vi) replacement

    NASA Astrophysics Data System (ADS)

    Aneja, Karanveer. S.; Bohm, Sivasambu; Khanna, A. S.; Bohm, H. L. Mallika

    2015-10-01

    Corrosion has been a perennial issue of concern for the steel industry. Chromate conversion coatings are well known pre-treatment coatings for steel but due to environmental concerns and legislations, their use has been restricted. The industrial community, pegged by these legislations, has been long demanding an economically viable and eco-friendly pre-treatment coating alternative, without having to compromise on the durability and corrosion performance of the overall coating system. The present study focuses on evaluation of graphene as an anticorrosive alternative to Cr(vi) based coatings. Graphene, produced by a high shear liquid exfoliation route, upon functionalisation, provides a conductive and nearly impermeable barrier coating. On electrochemical and coating performance evaluation of this coating system, a dramatic improvement in corrosion resistance is observed. The study confirms the environment friendly corrosion protection of steel using functionalised graphene coating.

  10. Ductile polyelectrolyte macromolecule-complexed zinc phosphate conversion crystal pre-coatings and topcoatings embodying a laminate

    DOEpatents

    Sugama, Toshifumi; Kukacka, Lawrence E.; Carciello, Neal R.

    1987-01-01

    This invention relates to a precoat, laminate, and method for ductile coatings on steel and non-ferrous metals which comprises applying a zinc phosphating coating solution modified by a solid polyelectrolyte selected from polyacrylic acid (PAA), polymethacrylic acid (PMA), polyitaconic acid (PIA), and poly-L-glutamic acid. The contacting of the resin with the phosphating solution is made for a period of up to 20 hours at about 80.degree. C. The polyelectrolyte or the precoat is present in about 0.5-5.0% by weight of the total precoat composition and after application, the precoat base is dried for up to 5 hours at about 150.degree. C. to desiccate. Also, a laminate may be formed where polyurethane (PU) is applied as an elastomeric topcoating or polyfuran resin is applied as a glassy topcoating. It has been found that the use of PAA at a molecular weight of about 2.times.10.sup.5 gave improved ductility modulus effect.

  11. Ductile polyelectrolyte macromolecule-complexed zinc phosphate conversion crystal pre-coatings and topcoatings embodying a laminate

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Carciello, N.R.

    1987-04-21

    This invention relates to a precoat, laminate, and method for ductile coatings on steel and non-ferrous metals which comprises applying a zinc phosphating coating solution modified by a solid polyelectrolyte selected from polyacrylic acid (PAA), polymethacrylic acid (PMA), polyitaconic acid (PIA), and poly-L-glutamic acid. The contacting of the resin with the phosphating solution is made for a period of up to 20 hours at about 80 C. The polyelectrolyte or the precoat is present in about 0.5--5.0% by weight of the total precoat composition and after application, the precoat base is dried for up to 5 hours at about 150 C to desiccate. Also, a laminate may be formed where polyurethane (PU) is applied as an elastomeric topcoating or polyfuran resin is applied as a glassy topcoating. It has been found that the use of PAA at a molecular weight of about 2 [times] 10[sup 5] gave improved ductility modulus effect. 5 figs.

  12. Preparation of chitosan-coated polyethylene packaging films by DBD plasma treatment.

    PubMed

    Theapsak, Siriporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana

    2012-05-01

    Polyethylene (PE) packaging films were coated with chitosan in order to introduce the antibacterial activity to the films. To augment the interaction between the two polymers, we modified the surfaces of the PE films by dielectric barrier discharge (DBD) plasma before chitosan coating. After that the plasma-treated PE films were immersed in chitosan acetate solutions with different concentrations of chitosan. The optimum plasma treatment time was 10 s as determined from contact angle measurement. Effect of the plasma treatment on the surface roughness of the PE films was investigated by atomic force microscope (AFM) while the occurrence of polar functional groups was observed by X-ray photoelectron spectroscope (XPS) and Fourier transformed infrared spectroscope (FTIR). It was found that the surface roughness as well as the occurrence of oxygen-containing functional groups (i.e., C═O, C-O, and -OH) of the plasma-treated PE films increased from those of the untreated one, indicating that the DBD plasma enhanced hydrophilicity of the PE films. The amounts of chitosan coated on the PE films were determined after washing the coated films in water for several number of washing cycles prior to detection of the chitosan content by the Kjaldahl method. The amounts of chitosan coated on the PE films were constant after washing for three times and the chitosan-coated PE films exhibited appreciable antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, the obtained chitosan-coated PE films could be a promising candidate for antibacterial food packaging.

  13. Laser Treatment of Electro-Spark Coatings Deposited in the Carbon Steel Substrate with using Nanostructured WC-Cu Electrodes

    NASA Astrophysics Data System (ADS)

    Radek, Norbert; Bartkowiak, Konrad

    The aim of this work was to investigate the influence of laser treatment for the improving mechanical and tribological properties coatings fabricated in the C45 carbon steel by ESD process. The studies were conducted using WC-Cu electrodes produced by sintering nanostructural powders and molten with a laser beam. The tests proved that ESD WC-Cu coatings are characterized by lower hardness and friction coefficient, but higher roughness. The result of laser processing improves structure by refinement, healing of microcracks and pores of ESD coatings. Laser treated ESD coatings can be applied in sliding friction pairs and as protective coatings.

  14. 40 CFR 721.10636 - Slimes and sludges, automotive coating, wastewater treatment, solid waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Slimes and sludges, automotive coating, wastewater treatment, solid waste. 721.10636 Section 721.10636 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL...

  15. 40 CFR 721.10636 - Slimes and sludges, automotive coating, wastewater treatment, solid waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Slimes and sludges, automotive coating, wastewater treatment, solid waste. 721.10636 Section 721.10636 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL...

  16. Surface pre-treatment for barrier coatings on polyethylene terephthalate

    NASA Astrophysics Data System (ADS)

    Bahre, H.; Bahroun, K.; Behm, H.; Steves, S.; Awakowicz, P.; Böke, M.; Hopmann, Ch; Winter, J.

    2013-02-01

    Polymers have favourable properties such as light weight, flexibility and transparency. Consequently, this makes them suitable for food packaging, organic light-emitting diodes and flexible solar cells. Nonetheless, raw plastics do not possess sufficient barrier functionality against oxygen and water vapour, which is of paramount importance for most applications. A widespread solution is to deposit thin silicon oxide layers using plasma processes. However, silicon oxide layers do not always fulfil the requirements concerning adhesion and barrier performance when deposited on films. Thus, plasma pre-treatment is often necessary. To analyse the influence of a plasma-based pre-treatment on barrier performance, different plasma pre-treatments on three reactor setups were applied to a very smooth polyethylene terephthalate film before depositing a silicon oxide barrier layer. In this paper, the influence of oxygen and argon plasma pre-treatments towards the barrier performance is discussed examining the chemical and topological change of the film. It was observed that a short one-to-ten-second plasma treatment can reduce the oxygen transmission rate by a factor of five. The surface chemistry and the surface topography change significantly for these short treatment times, leading to an increased surface energy. The surface roughness rises slowly due to the development of small spots in the nanometre range. For very long treatment times, surface roughness of the order of the barrier layer's thickness results in a complete loss of barrier properties. During plasma pre-treatment, the trade-off between surface activation and roughening of the surface has to be carefully considered.

  17. Prospects of DLC coating as environment friendly surface treatment process.

    PubMed

    Kim, S W; Kim, S G

    2011-06-01

    After first commercialization in 90's, the applications of diamond-like carbon (DLC) have been significantly expanded to tool, automobile parts, machineries and moulds to enhance wear and friction properties. Although DLC has many advantages like high hardness, low friction electrical insulating and chemical stability and has the possible market, its application in the field is still very limited due to the gaps of understanding between end-user and developer of its advantage of costing. Recently, one of the most popular issues in the surface modification is providing the long lasting super-hydrophilic or -hydrophobic properties on the material surface for the outdoor usage. A lot of material loss is caused due to water corrosion which has to do with the flow and contacts of water like fuel cell separator and air conditioner parts. The consequence of development of functional surface based on the hydrophilic or hydrophobic design for the important parts would be really helpful for materials to be cleaner and more energy effective. Here, we first reviewed the DLC technology and then examined the kind of surface modification as well as its merits and disadvantage. We also looked at how we can improve super-hydrophilic and super hydrophobic for the DLC coating layer as well as current status of technology and arts of DLC. In the end, we would like to suggest it as one of the environmental friendly industrial technology. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  18. Characterization and oxidation behavior of NiCoCrAlY coating fabricated by electrophoretic deposition and vacuum heat treatment

    NASA Astrophysics Data System (ADS)

    Li, Zhiming; Qian, Shiqiang; Wang, Wei

    2011-03-01

    Electrophoretic deposition (EPD) was showed to be a feasible and convenient method to fabricate NiCoCrAlY coatings on nickel based supperalloys. The microstructure and composition of the NiCoCrAlY coatings after vacuum heat treatment were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX). Isothermal-oxidation test was performed at 1100 °C in static air for 100 h. The results show that the major phases in electrophoretic deposited and vacuum heat treated NiCoCrAlY coating are γ-Ni and γ‧-Ni3Al phases, also there is an extremely small quantity of Al2O3 in the coating. Composition fluctuations occur in the coating and a certain amount of titanium diffuse from the superalloy substrate to the top of the coating during vacuum heat treatment. The oxidation test results exhibit that the oxidation kinetics of this coating has two typical stages. The protective oxide layer is mainly formed in the initial linear growth stage and then the oxide layer hinders further oxidation of the coating in the subsequent parabolic growth stage. The coating can effectively protect the superalloy substrate from oxidation. A certain amount of rutile TiO2 is formed in the coating during oxidation and it is adverse to the oxidation resistance of the coating.

  19. Multifunctional UV (MUV) Coatings and Ce-based Materials

    DTIC Science & Technology

    2008-02-01

    Coat Metallic Substrate Non-Chromate Conversion Coating Multifunctional UV (MUV)- Curable Coating Current 3...Layer, Cr(VI) Based Coating System 2 Layer, UV Curable Coating System With No Cr(VI) and No VOCs Technical Objective Surface Finishing Workshop Feb 08... UV Curable Coatings and Inhibitors Non-Chromate Pretreatments Multifunctional UV (MUV) Coating Conversion Coating Characterization,

  20. Structure and properties of alloys and coatings with ordered β-phase after heat treatment

    NASA Astrophysics Data System (ADS)

    Pugacheva, N. B.

    2007-05-01

    Ways for changing the structure and properties of alloys of the Cu-Zn-Fe-Mn-Si system due to formation of required amount of CuZn ordered β-phase with specific grain size during heat treatment and for raising the endurance of alloys of the Fe-Cr-Al system due to formation of ordered DO 3 -or B2-phases in the α-solid solution during aluminizing are considered. The effect of the composition of alumosilicide β-coatings on their protective properties is analyzed, including their resistance to cracking upon rapid cooling. The effect of boron on the endurance of such coatings is studied.

  1. Enhancing the conversion efficiency of red emission by spin-coating CdSe quantum dots on the green nanorod light-emitting diode.

    PubMed

    Lee, Ya-Ju; Lee, Chia-Jung; Cheng, Chun-Mao

    2010-11-08

    A hybrid structure of CdSe quantum dots (QDs) (λ = 640 nm) spin-coated on the indium gallium nitride (InGaN) nanorod light-emitting diode (LED, λ = 525 nm) is successfully fabricated. Experimental results indicate that the randomness and the minuteness of nanorods scatter the upcoming green light into the surrounding CdSe QDs efficiently, subsequently alleviating the likelihood of the emitted photons of red emission being recaptured by the CdSe QDs (self-absorption effect), and that increases the coupling probability of emission lights and the overall conversion efficiency. Moreover, the revealed structure with high color stability provides an alternative solution for general lighting applications of next generation.

  2. Enhanced Conversion Efficiency of Cu(In,Ga)Se2 Solar Cells via Electrochemical Passivation Treatment.

    PubMed

    Tsai, Hung-Wei; Thomas, Stuart R; Chen, Chia-Wei; Wang, Yi-Chung; Tsai, Hsu-Sheng; Yen, Yu-Ting; Hsu, Cheng-Hung; Tsai, Wen-Chi; Wang, Zhiming M; Chueh, Yu-Lun

    2016-03-01

    Defect control in Cu(In,Ga)Se2 (CIGS) materials, no matter what the defect type or density, is a significant issue, correlating directly to PV performance. These defects act as recombination centers and can be briefly categorized into interface recombination and Shockley-Read-Hall (SRH) recombination, both of which can lead to reduced PV performance. Here, we introduce an electrochemical passivation treatment for CIGS films that can lower the oxygen concentration at the CIGS surface as observed by X-ray photoelectron spectrometer analysis. Temperature-dependent J-V characteristics of CIGS solar cells reveal that interface recombination is suppressed and an improved rollover condition can be achieved following our electrochemical treatment. As a result, the surface defects are passivated, and the power conversion efficiency performance of the solar cell devices can be enhanced from 4.73 to 7.75%.

  3. Effect of hydrothermal treatment model on stability and bioactivity of microarc oxidized titania coatings

    NASA Astrophysics Data System (ADS)

    Zhou, Jianhong; Shao, Jianmin; Han, Yong

    2014-06-01

    Different types of Sr-doped hydroxyapatite (Sr-HA) nanorod arrays were prepared on microarc oxidized (MAOed) TiO2 coatings after hydrothermal treatment (HT) for 24 h in the case of different HT models, namely the MAOed TiO2 coatings to be hanged up in the autoclave without touching the HT solution (termed as H-HT) and immersed in the HT solution (termed as I-HT). The MAO+H-HT (HT in the case of H-HT model) and MAO+I-HT (HT in the case of I-HT model) coatings are multilayered by nanorod-shaped Sr-HA as outer layer, Ca0.5Sr0.5TiO3 as middle layer and TiO2 as inner layer adjacent to Ti substrate. The Sr-HA nanorods on the coatings are randomly oriented, homogeneous and a similar mean diameter of 70 nm. However, the lateral spacing between the Sr-HA nanorods on MAO+H-HT coating is much smaller compared with those on MAO+I-HT coating. The effects of the HT models on the roughness, in vitro structure and bond strength stability and apatite inducing ability of the coatings were examined. AFM evaluation reveals that the coatings have a similar microscale roughness. The as-MAOed, MAO+H-HT and MAO+I-HT coatings exhibit long-term structure and adhesive strength stability as indicated by immersion tests in physiological saline solutions for 0-48 weeks, although their adhesive strengths decrease a little after immersion in physiological saline solutions, for example, to about 10.2%, 7.8% and 6.9% at 48 weeks, respectively. Furthermore, the MAO+H-HT coating can induce apatite formation after 12 h of SBF immersion due to the compacted Sr-HA nanorods layer, and the induced apatite prefers to nucleate on the basal-faceted surfaces of Sr-HA nanorods.

  4. Surface Pre-treatment for Thermally Sprayed ZnAl15 Coatings

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Knoch, M. A.

    2016-12-01

    Pre-treatment of substrates is an important step in thermal spraying. It is widely accepted that mechanical interlocking is the dominant adhesion mechanism for most substrate-coating combinations. To prevent premature failure, minimum coating adhesion strength, surface preparation grades, and roughness parameters are often specified. For corrosion-protection coatings for offshore wind turbines, an adhesion strength ≥ 5 MPa is commonly assumed to ensure adhesion over service lifetime. In order to fulfill this requirement, Rz > 80 µm and a preparation grade of Sa3 are common specifications. In this study, the necessity of these requirements is investigated using the widely used combination of twin-wire arc-sprayed ZnAl15 on S355J2 + N as a test case. By using different blasting media and parameters, the correlation between coating adhesion and roughness parameters is analyzed. The adhesion strength of these systems is measured using a test method allowing measurements on real parts. The results are compared to DIN EN 582:1993, the European equivalent of ASTM-C633. In another series of experiments, the influence of surface pre-treatment grades Sa2.5 and Sa3 is considered. By combining the results of these three sets of experiments, a guideline for surface pre-treatment and adhesion testing on real parts is proposed for the considered system.

  5. Hot water treatment and insecticidal coatings for disinfesting limes of mealybugs (Homoptera: Pseudococcidae).

    PubMed

    Gould, W P; McGuire, R G

    2000-06-01

    Hot water immersion and insecticidal coatings were tested to determine if they could be used to disinfest Persian limes, Citrus latifolia Tanaka, of the mealybug pests Planococcus citri Risso and Pseudococcus odermatti Miller & Williams. A 20-min 49 degrees C hot water immersion treatment is effective in killing mealybugs and all other arthropods tested found externally on limes, or under the calyx. No insects or mites were found to survive after the 20-min hot water treatment. In this test, 7,200 limes were treated with 1,308 insects killed and zero survivors. Treatment at 49 degrees C for 20 min did not significantly affect quality when treated fruit were compared with untreated control fruit. Four coatings were tested at a 3% rate: two petroleum-based oils (Ampol and Sunspray oil), a vegetable oil (natural oil), and a soap (Mpede). The coatings gave up to 94% kill (Ampol) of mealybugs, which is not sufficient to provide quarantine security. The coatings might be effective as a postharvest dip before shipment.

  6. Surface treatments and coatings to maintain fresh-cut mango quality in storage.

    PubMed

    Plotto, Anne; Narciso, Jan A; Rattanapanone, Nithiya; Baldwin, Elizabeth A

    2010-10-01

    Edible coatings may extend fresh-cut fruit storage by preventing moisture loss and decreasing gas exchange. This study evaluated the effect of an antibrowning dip (calcium ascorbate, citric acid and N-acetyl-L-cysteine), followed or not with carboxymethylcellulose (CMC) or carrageenan coatings on quality of fresh-cut mangoes stored at 5 °C for up to 20 days. A fourth treatment, only used in one of four experiments, consisted of chitosan. Treatments were applied on 'Tommy Atkins', 'Kent' and 'Keitt' mangoes harvested from Homestead (FL), and on imported store-bought mangoes. The antibrowning dips maintained the best visual quality during storage for all cultivars, as indicated by higher b*, hue and L*. The CMC coating maintained similar visual quality, but carrageenan or chitosan decreased L* and b*. The antibrowning dip containing calcium ascorbate reduced firmness loss on cut pieces of 'Keitt', 'Kent' and store-bought mangoes. The antibrowning treatment maintained higher titratable acidity for 'Kent' and 'Keitt', resulting in lower sensory sweetness. This study with repeated experiments showed that calcium ascorbate with citric acid and N-acetyl-L-cysteine maintained cut mango slices attractiveness in storage by keeping light color in both varieties. The addition of a polysaccharide coating did not consistently improve quality.

  7. Surface Pre-treatment for Thermally Sprayed ZnAl15 Coatings

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Knoch, M. A.

    2017-02-01

    Pre-treatment of substrates is an important step in thermal spraying. It is widely accepted that mechanical interlocking is the dominant adhesion mechanism for most substrate-coating combinations. To prevent premature failure, minimum coating adhesion strength, surface preparation grades, and roughness parameters are often specified. For corrosion-protection coatings for offshore wind turbines, an adhesion strength ≥ 5 MPa is commonly assumed to ensure adhesion over service lifetime. In order to fulfill this requirement, Rz > 80 µm and a preparation grade of Sa3 are common specifications. In this study, the necessity of these requirements is investigated using the widely used combination of twin-wire arc-sprayed ZnAl15 on S355J2 + N as a test case. By using different blasting media and parameters, the correlation between coating adhesion and roughness parameters is analyzed. The adhesion strength of these systems is measured using a test method allowing measurements on real parts. The results are compared to DIN EN 582:1993, the European equivalent of ASTM-C633. In another series of experiments, the influence of surface pre-treatment grades Sa2.5 and Sa3 is considered. By combining the results of these three sets of experiments, a guideline for surface pre-treatment and adhesion testing on real parts is proposed for the considered system.

  8. Effect of Heat Treatment on Wear Resistance of Nickel Aluminide Coatings Deposited by HVOF and PTA

    NASA Astrophysics Data System (ADS)

    Benegra, M.; Santana, A. L. B.; Maranho, O.; Pintaude, G.

    2015-08-01

    This study aims to compare the wear resistance of nickel aluminide coatings deposited using plasma transferred arc (PTA) and high-velocity oxygen fuel (HVOF) processes. Wear resistance was measured in rubber wheel abrasion tests. In both deposition processes, the same raw material (nickel aluminide powder) was atomized and deposited on a 316L steel plate substrate. After deposition, specimens were subjected to thermal cycling, aiming solubilization and precipitation. Coatings deposited using PTA developed different microstructures as a result of the incorporation of substrate elements. However, despite the presence of these microstructures, they performed better than coatings processed using HVOF before the heat treatment. After thermal cycling, the superficial hardness after the wear tests for both processes was similar, resulting in similar mass losses.

  9. Advanced zinc phosphate conversion and pre-ceramic polymetallosiloxane coatings for corrosion protection of steel and aluminum, and characteristics of polyphenyletheretherketone-based materials. Final report

    SciTech Connect

    Sugama, T.; Carciello, N.R.

    1992-07-01

    Anhydrous zinc phosphate (Zn{center_dot}Ph) coatings deposited by immersing the steel in transition Co, Ni, and Mn cation-incorporated phosphating solutions were investigated. Two features for the anhydrous 340C-heated (Zn{center_dot}Ph) were addressed; one was to determine if electron trapping of adsorbed CO{sup 2+} and Ni{sup 2+} ions acts to inhibit the cathodic reaction on the (Zn{center_dot}Ph), and the second was to determine the less susceptibility of the {alpha}-Zn{sub 3}(PO{sub 4}){sub 2} phase to alkali-induced dissolution. The factors governing film-forming of pre-ceramic polymetallosiloxane (PMS) coatings for Al substrates were investigated. Four factors were important in obtaining a good film: (1) formation of organopolymetallosiloxane at sintering temperatures of 150C; (2) pyrolytic conversion at 350C into an amorphous PMS network structure in which the Si-O-M linkage were moderately enhanced; (3) noncrystalline phases; and (4) formation of interfacial oxane bond between PMS and Al oxide. Formation of well-crystallized polyphenyletheretherketone (PEEK) in vicinity of silica aggregates was found in the molted body made in N{sub 2}. Crystalline PEEK contributed to thermal and hydrothermal stabilities of mortar specimens at temperatures up to 200C, and resistance in 5 wt % H{sub 2}SO{sub 4} solution at 80C.

  10. Plasma Sprayed Bondable Stainless Surface (BOSS) Coatings for Corrosion Protection and Adhesion Treatments

    NASA Technical Reports Server (NTRS)

    Davis, G. D.; Groff, G. B.; Rooney, M.; Cooke, A. V.; Boothe, R.

    1995-01-01

    Plasma-sprayed Bondable Stainless Surface (BOSS) coatings are being developed under the Solid Propulsion Integrity Program's (SPIP) Bondlines Package. These coatings are designed as a steel case preparation treatment prior to insulation lay-up. Other uses include the exterior of steel cases and bonding surfaces of nozzle components. They provide excellent bondability - rubber insulation and epoxy bonds fail cohesively within the polymer - for both fresh surfaces and surfaces having undergone natural and accelerated environmental aging. They have passed the MSFC requirements for protection of inland and sea coast environment. Because BOSS coatings are inherently corrosion resistant, they do not require preservation by greases or oils. The reduction/elimination of greases and oils, known bondline degraders, can increase SRM reliability, decrease costs by reducing the number of process steps, and decrease environmental pollution by reducing the amount of methyl chloroform used for degreasing and thus reduce release of the ozone-depleting chemical in accordance with the Clean Air Act and the Montreal Protocol. The coatings can potential extend the life of RSRM case segments and nozzle components by eliminating erosion due to multiple grit blasting during each use cycle and corrosion damage during marine recovery. Concurrent work for the Air Force show that other BOSS coatings give excellent bondline strength and durability for high-performance structures of aluminum and titanium.

  11. Plasma Sprayed Bondable Stainless Surface (BOSS) Coatings for Corrosion Protection and Adhesion Treatments

    NASA Technical Reports Server (NTRS)

    Davis, G. D.; Groff, G. B.; Rooney, M.; Cooke, A. V.; Boothe, R.

    1995-01-01

    Plasma-sprayed Bondable Stainless Surface (BOSS) coatings are being developed under the Solid Propulsion Integrity Program's (SPIP) Bondlines Package. These coatings are designed as a steel case preparation treatment prior to insulation lay-up. Other uses include the exterior of steel cases and bonding surfaces of nozzle components. They provide excellent bondability - rubber insulation and epoxy bonds fail cohesively within the polymer - for both fresh surfaces and surfaces having undergone natural and accelerated environmental aging. They have passed the MSFC requirements for protection of inland and sea coast environment. Because BOSS coatings are inherently corrosion resistant, they do not require preservation by greases or oils. The reduction/elimination of greases and oils, known bondline degraders, can increase SRM reliability, decrease costs by reducing the number of process steps, and decrease environmental pollution by reducing the amount of methyl chloroform used for degreasing and thus reduce release of the ozone-depleting chemical in accordance with the Clean Air Act and the Montreal Protocol. The coatings can potential extend the life of RSRM case segments and nozzle components by eliminating erosion due to multiple grit blasting during each use cycle and corrosion damage during marine recovery. Concurrent work for the Air Force show that other BOSS coatings give excellent bondline strength and durability for high-performance structures of aluminum and titanium.

  12. Ductile polyelectrolyte macromolecule-complexed zinc phosphate conversion crystal pre-coatings and topcoatings embodying a laminate

    DOEpatents

    Sugama, Toshifumi; Kukacka, L.E.; Carciello, N.R.

    1985-11-05

    This invention relates to a precoat, laminate, and method for ductile coatings on steel and non-ferrous metals which comprises applying a zinc phosphating coating solution modified by a solid polyelectrolyte selected from polyacrylic acid (PAA), polymethacrylic acid (PMA), polyitaconic acid (PIA), and poly-L-glutamic acid. The contacting of the resin with the phosphating solution is made for a period of up to 20 hours at about 80/sup 0/C. The polyelectrolyte or the precoat is present in about 0.5 to 5.0% by weight of the total precoat composition and after application, the precoat base is dried for up to 5 hours at about 150/sup 0/C to desiccate. Also, a laminate may be formed where polyurethane (PU) is applied as an elastomeric topcoating or polyfuran resin is applied as a glassy topcoating. It has been found that the use of PAA at a molecular weight of about 2 x 10/sup 5/ gave improved ductility modulus effect.

  13. [Efficacy and adverse effects of film coated praziquantel for treatment of schistosomiasis japonica].

    PubMed

    Xu, Jing; Guo, Jia-gang; Wu, Xiao-hua; Zeng, Xiao-jun; Yang, Wei-ping; Yang, Guang-bin; Zheng, Jiang; Zhou, Xiao-nong

    2009-08-01

    To understand the adverse and curative effects of film coated praziquantel for treatment of schistosomiasis japonica. A questionnaire survey was conducted among 6 to 65 years old inhabitants from epidemic areas of schistosomiasis japonica in Jiangxi, Anhui and Hubei provinces, while indirect haemagglutination assay (IHA) was also administrated. The Serological positives were tested by Kato-Katz technique. A total of 509 habitats of serological positives and healthy persons were given praziquantel. 460 targets with no relative symptoms were followed up for adverse effect of drugs in one month and efficacy evaluation of praziquantel was carried out in 104 parasitological positives 3 months post-treatment. The 84.7% (144/170) individuals thought film coated tablets were no smell or only with little smell while 92.9%(315/339) targets in control group fell that tablets smelled bad. The total side effect rates of film coated praziquantel group and control group in 1-2 hours post-treatment were 20.30% (27/133) and 83.18% (272/327) respectively. There was significantly different between two groups (chi(2) = 164.316, P < 0.05). The adverse effect rates of film coated praziquantel group in neuromuscular system, digestive system and cardiovascular system were 15.79% (21/133), 9.77% (13/133), 2.26% (3/133) individually which were significantly lower than those of control groups with 81.65% (267/327), 49.24% (161/327), 12.84% (42/327) in corresponding systems (chi(2)(neuromuscular system) = 175.188, chi(2)(digestive system) = 62.601, chi(2)(cardiovascular system) = 12.010, P < 0.05). And the adverse effect rate of allergic reaction of film coated group was no significant difference with control group (2.26%(3/133) versus 0.92% (3/327), chi(2) = 1.315, P = 0.235). One day after treatment, the adverse effect rate of film coated tablets of praziquantel decreased to 3.01% (4/133), significantly lower than that of control group (P < 0.05). There was no significant difference after 2

  14. Postdeposition treatment of IBS coatings for UV applications with optimized thin-film stress properties.

    PubMed

    Bischoff, Martin; Nowitzki, Tobias; Voß, Oliver; Wilbrandt, Steffen; Stenzel, Olaf

    2014-02-01

    Ion-beam-sputtering (IBS) single-layer and multilayer coating designs for UV applications were examined after the deposition process as well as after a defined postdeposition treatment. High internal compressive film stress as well as moderate absorption losses in the UV spectral range were measured at the as-deposited thin films. Due to a controlled postdeposition treatment process, the absorption losses and the high compressive stress can be reduced significantly. We show that the remaining thin-film stress of SiO2 and HfO2 multilayer designs can be specifically manipulated by the parameters of the postdeposition treatment. Even zero and tensile stress can be achieved for complex multilayer coatings.

  15. Heat Treatment Influences Monomer Conversion and Bond Strength of Indirect Composite Resin Restorations.

    PubMed

    Magne, Pascal; Malta, Daniel Alexandre Menezes Pedrosa; Enciso, Reyes; Monteiro-Junior, Sylvio

    2015-12-01

    To assess the resin microtensile bond strength (MTBS) and the degree of conversion (DC) of indirect composite resin restorations polymerized with light and heat. Two direct (Filtek Z100 and Premise) and one indirect (Premise Indirect) composite resins were polymerized with a combination of light and heat (138°C for 20 min). For MTBS, 42 cylinders were fabricated (n = 7). After the surface treatment, cylinders were bonded to each other using adhesive resin (Optibond FL). Specimens were stored in water for 24 h. Another 15 cylinders (n = 5) were fabricated for determining degree of conversion using Fourier Transform Infrared Spectrometry immediately and at 24 h. The MTBS and the DC was submitted to two-way ANOVA. The interaction with existing data was explored with univariate ANOVA and two-way ANOVA. Tukey's HSD post-hoc test was used to detect pairwise differences (α = 0.05). The MTBS to light and heat polymerized Z100 was 75.7 MPa, significantly higher than that to Premise (58.6 MPa) and Premise Indirect (63.9 MPa). The immediate DC for Z100, Premise, and Premise Indirect were 51.0%, 68.7%, and 61.8%, respectively. The DC at 24 h ranged from 53.4% (Z100) to 72.8% (Premise Indirect) and significantly increased for Premise Indirect only. Comparison with previously published data revealed that the heat treatment increased both MTBS and DC of Premise and Premise Indirect. Z100 showed better bond strength but lower DC. Heat treatment and a 24-h delay before delivery can benefit DC of Premise Indirect. The increase in DC of Premise and Premise Indirect did not affect their bond strength.

  16. High-rate anaerobic wastewater treatment: diversifying from end-of-the-pipe treatment to resource-oriented conversion techniques.

    PubMed

    van Lier, Jules B

    2008-01-01

    Decades of developments and implementations in the field of high-rate anaerobic wastewater treatment have put the technology at a competitive level. With respect to sustainability and cost-effectiveness, anaerobic treatment has a much better score than many alternatives. Particularly, the energy conservation aspect, i.e. avoiding the loss of energy for destruction of organic matter, while energy is reclaimed from the organic waste constituents in the form of biogas, was an important driver in the development of such systems. Invoked by the present greenhouse alert, the energy involved is nowadays translated into carbon credits, providing another incentive to further implement anaerobic technology. Anaerobic conversion processes, however, offer much more than cost-effective treatment systems. Selective recovery of metals, effective desulphurization, recovery of nutrients, reductive detoxification, and anaerobic oxidation of specific compounds are examples of the potentials of anaerobic treatment. This paper presents a survey on the state of the art of full-scale anaerobic high-rate treatment of industrial wastewaters and highlights current trends in anaerobic developments. (c) IWA Publishing 2008.

  17. TF-XRD examination of surface-reactive TiO2 coatings produced by heat treatment and CO2 laser treatment.

    PubMed

    Moritz, Niko; Areva, Sami; Wolke, Joop; Peltola, Timo

    2005-07-01

    When surface-reactive (bioactive) coatings are applied to medical implants by means of CO2 laser processing, the bioactivity of the surface of the implant can be locally modified to match the properties of the surrounding tissues to provide a firm fixation of the implant. The aim of this study was to compare the heat treated TiO2 coatings with the laser-treated TiO2 coatings in terms of amorphous-crystalline-phase development. The coatings were characterized with thin-film X-ray diffraction (TF-XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The TiO2 coatings heat treated at 500 degrees C known to be bioactive in SBF (simulated body fluid) consisted mainly of anatase with some rutile-phase, suggesting a predominant effect of anatase on reactivity of coatings. However, the coatings preheat-treated at 500 degrees C with further laser treatment exhibited enhanced bioactivity while consisting mainly of rutile. These findings indicated a key role of both rutile and anatase for the reactivity of the coatings. Without preheat treatment, by laser treatment alone, the amorphous titania coatings developed into mixed anatase/rutile containing coatings. This structural organization and the increase in crystal size are thus considered to be the reasons for their bioactivity. The SBF results indicate the possibility to control bioactivity by altering laser power used through the anatase/rutile crystallinity enhancement.

  18. Oxide-bioceramic coatings obtained on titanium items by the induction heat treatment and modified with hydroxyapatite nanoparticles

    NASA Astrophysics Data System (ADS)

    Fomin, Aleksandr A.; Fomina, Marina A.; Rodionov, Igor V.; Koshuro, Vladimir A.; Petrova, Natalia V.; Skaptsov, Aleksandr A.; Atkin, Vsevolod S.

    2015-06-01

    Prospective composite bioceramic titania coatings were obtained on intraosseous implants fabricated from cp-titanium and medical titanium alloy VT16 (Ti-2.5Al-5Mo-5V). Consistency changes of morphological characteristics, mechanical properties and biocompatibility of experimental titanium implant coatings obtained by oxidation during induction heat treatment are defined. Technological recommendations for obtaining bioceramic coatings with extremely high strength on titanium items surface are given.

  19. Influence of Processing and Heat Treatment on Corrosion Resistance and Properties of High Alloyed Steel Coatings

    NASA Astrophysics Data System (ADS)

    Hill, Horst; Weber, Sebastian; Raab, Ulrich; Theisen, Werner; Wagner, Lothar

    2012-09-01

    Corrosion and abrasive wear are two important aspects to be considered in numerous engineering applications. Looking at steels, high-chromium high-carbon tool steels are proper and cost-efficient materials. They can either be put into service as bulk materials or used as comparatively thin coatings to protect lower alloyed construction or heat treatable steels from wear and corrosion. In this study, two different corrosion resistant tool steels were used for the production of coatings and bulk material. They were processed by thermal spraying and super solidus liquid phase sintering as both processes can generally be applied to produce coatings on low alloyed substrates. Thermally sprayed (high velocity oxygen fuel) coatings were investigated in the as-processed state, which is the most commonly used condition for technical applications, and after a quenching and tempering treatment. In comparison, sintered steels were analyzed in the quenched and tempered condition only. Significant influence of alloy chemistry, processing route, and heat treatment on tribological properties was found. Experimental investigations were supported by computational thermodynamics aiming at an improvement of tribological and corrosive resistance.

  20. Chitosan-coated Sorbents for In Situ Treatment of Nonpoint Source Contaminants in Urban Runoff

    NASA Astrophysics Data System (ADS)

    Olson, P. R.; Lee, E.; Solpuker, U.; Schwartz, F. W.; Kim, Y.; Jeon, B.

    2010-12-01

    Urban runoff is becoming an increasingly daunting environmental issue, plaguing nations around the world. Water bodies surrounding urban areas have seen an increase in water quality degradation from pollutants such as, heavy metals (Fe, Pb, Cd, etc.) and nitrates. While Best Management Practices (BMPs) are being implemented to reduce the pollutant load to urban water bodies, efficiently treating pollutants in urban runoff remains a challenge. In this study, we aim to develop an in situ treatment scheme using chitosan as a sorbent for heavy metals and nitrates. Chitosan hydrogel beads cross-linked with alginate and chitosan-coated inert grains have been developed. While column test data indicated high sorption capacity for the chitosan beads and chitosan-coated media, the need for development of a chitosan-coated porous media was identified. Chitosan-coated multi-porous media that can provide a treatment option for pollutants in short-term, high-flows in urban storm runoff will provide an alternative to BMPs that will effectively remove heavy metal and nitrate contaminants.

  1. Caloric vestibular stimulation as a treatment for conversion disorder: a case report and medical hypothesis.

    PubMed

    Noll-Hussong, Michael; Holzapfel, Sabrina; Pokorny, Dan; Herberger, Simone

    2014-01-01

    Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation has been demonstrated to modulate a variety of cognitive functions associated with brain activations, especially in the temporal-parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure.

  2. Consolidated conversion of hulled barley into fermentable sugars using chemical, thermal, and enzymatic (CTE) treatment.

    PubMed

    Kim, Tae Hyun; Nghiem, Nhuan P; Taylor, Frank; Hicks, Kevin B

    2011-06-01

    A novel process using chemical, thermal, and enzymatic treatment for conversion of hulled barley into fermentable sugars was developed. The purpose of this process is to convert both lignocellulosic polysaccharides and starch in hulled barley grains into fermentable sugars simultaneously without a need for grinding and hull separation. In this study, hulled barley grains were treated with 0.1 and 1.0 wt.-% sulfuric acid at various temperatures ranging from 110 to 170 °C in a 63-ml flow-through packed-bed stainless steel reactor. After sulfuric acid pretreatment, simultaneous conversion of lignocellulose and starch in the barley grains into fermentable sugars was performed using an enzyme cocktail, which included α-amylase, glucoamylase, cellulase, and β-glucosidase. Both starch and non-starch polysaccharides in the pre-treated barley grains were readily converted to fermentable sugars. The treated hulled barley grains, including their hull, were completely hydrolyzed to fermentable sugars with recovery of almost 100% of the available glucose and xylose. The pretreatment conditions of this chemical, thermal, and enzymatic (CTE) process for achieving maximum yield of fermentable sugars were 1.0 wt.% sulfuric acid and 110 °C. In addition to starch, the acid pretreatment also retained most of the available proteins in solid form, which is essential for subsequent production of fuel ethanol and high protein distiller's dried grains with solubles co-product.

  3. Caloric Vestibular Stimulation as a Treatment for Conversion Disorder: A Case Report and Medical Hypothesis

    PubMed Central

    Noll-Hussong, Michael; Holzapfel, Sabrina; Pokorny, Dan; Herberger, Simone

    2014-01-01

    Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation has been demonstrated to modulate a variety of cognitive functions associated with brain activations, especially in the temporal–parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure. PMID:24917828

  4. Kinetic modelling of aflatoxins B1 conversion and validation in corn, rice, and peanut during thermal treatments.

    PubMed

    Zhang, Chao; Ma, Yue; Zhao, Xiaoyan; Zeng, Yali; Wang, Fen

    2011-12-01

    A kinetic model of the aflatoxins B1 conversion was plotted and validated successfully in the aflatoxin B1-contaminated rice during thermal treatments. Specifically, the kinetic Model A and Model B of the aflatoxin B1 conversion were plotted based on the differential-scanning calorimetry and thermogravimetric analysis, respectively, with the pure aflatoxin B1. In succession, Model A and Model B were validated in the aflatoxin B1-contaminated corn, rice, and peanut during thermal treatments. Model A successfully simulated the conversion of aflatoxin B1 in the aflatoxin B1-contaminated rice with the correlation coefficients of 0.859 and average-absolute deviation of 6.61. The activation energy and conversion order of the aflatoxin B1 conversion were 89.0kJ/mol and 0.12, respectively. Moreover, the relationships between the conversion degree and time vs temperature were plotted based on Model A. These plots would help to predict the final content of aflatoxin B1 after thermal treatments, and give an instruction to develop a food processing.

  5. Surface charge-conversion polymeric nanoparticles for photodynamic treatment of urinary tract bacterial infections.

    PubMed

    Liu, Shijie; Qiao, Shenglin; Li, Lili; Qi, Guobin; Lin, Yaoxin; Qiao, Zengying; Wang, Hao; Shao, Chen

    2015-12-11

    Urinary tract infections are typical bacterial infections which result in a number of economic burdens. With increasing antibiotic resistance, it is urgent that new approaches are explored that can eliminate pathogenic bacteria without inducing drug resistance. Antimicrobial photodynamic therapy (PDT) is a new promising tactic. It is a gentle in situ photochemical reaction in which a photosensitizer (PS) generates reactive oxygen species (ROS) under laser irradiation. In this work, we have demonstrated Chlorin e6 (Ce6) encapsulated charge-conversion polymeric nanoparticles (NPs) for efficiently targeting and killing pathogenic bacteria in a weakly acidic urinary tract infection environment. Owing to the surface charge conversion of NPs in an acidic environment, the NPs exhibited enhanced recognition for Gram-positive (ex. S. aureus) and Gram-negative (ex. E. coli) bacteria due to the charge interaction. Also, those NPs showed significant antibacterial efficacy in vitro with low cytotoxicity. The MIC value of NPs to E. coli is 17.91 μg ml(-1), compared with the free Ce6 value of 29.85 μg ml(-1). Finally, a mouse acute cystitis model was used to assess the photodynamic therapy effects in urinary tract infections. A significant decline (P < 0.05) in bacterial cells between NPs and free Ce6 occurred in urine after photodynamic therapy treatment. And the plated counting results revealed a remarkable bacterial cells drop (P < 0.05) in the sacrificed bladder tissue. Above all, this nanotechnology strategy opens a new door for the treatment of urinary tract infections with minimal side effects.

  6. Surface charge-conversion polymeric nanoparticles for photodynamic treatment of urinary tract bacterial infections

    NASA Astrophysics Data System (ADS)

    Liu, Shijie; Qiao, Shenglin; Li, Lili; Qi, Guobin; Lin, Yaoxin; Qiao, Zengying; Wang, Hao; Shao, Chen

    2015-12-01

    Urinary tract infections are typical bacterial infections which result in a number of economic burdens. With increasing antibiotic resistance, it is urgent that new approaches are explored that can eliminate pathogenic bacteria without inducing drug resistance. Antimicrobial photodynamic therapy (PDT) is a new promising tactic. It is a gentle in situ photochemical reaction in which a photosensitizer (PS) generates reactive oxygen species (ROS) under laser irradiation. In this work, we have demonstrated Chlorin e6 (Ce6) encapsulated charge-conversion polymeric nanoparticles (NPs) for efficiently targeting and killing pathogenic bacteria in a weakly acidic urinary tract infection environment. Owing to the surface charge conversion of NPs in an acidic environment, the NPs exhibited enhanced recognition for Gram-positive (ex. S. aureus) and Gram-negative (ex. E. coli) bacteria due to the charge interaction. Also, those NPs showed significant antibacterial efficacy in vitro with low cytotoxicity. The MIC value of NPs to E. coli is 17.91 μg ml-1, compared with the free Ce6 value of 29.85 μg ml-1. Finally, a mouse acute cystitis model was used to assess the photodynamic therapy effects in urinary tract infections. A significant decline (P < 0.05) in bacterial cells between NPs and free Ce6 occurred in urine after photodynamic therapy treatment. And the plated counting results revealed a remarkable bacterial cells drop (P < 0.05) in the sacrificed bladder tissue. Above all, this nanotechnology strategy opens a new door for the treatment of urinary tract infections with minimal side effects.

  7. Application of nitrogen sufficiency conversion strategy for microalgae-based ammonium-rich wastewater treatment.

    PubMed

    Wang, Jinghan; Zhou, Wenguang; Yang, Haizhen; Ruan, Roger

    2016-10-01

    Ammonium ([Formula: see text]-N)-rich wastewater, a main cause for eutrophication, can serve as a promising medium for fast microalgae cultivation with efficient [Formula: see text]-N removal. To achieve this goal, a well-controlled three-stage treatment process was developed. Two trophic modes (mixotrophy and heterotrophy) in Stage 1 and Stage 2, with two nitrogen availability conditions (N sufficient and N deprived) in Stage 2, and different [Formula: see text]-N concentrations in Stage 3 were compared to investigate the effects of nitrogen sufficiency conversion on indigenous strain UMN266 for [Formula: see text]-N removal. Results showed that mixotrophic cultures in the first two stages with N deprivation in Stage 2 was the optimum treatment strategy, and higher [Formula: see text]-N concentration in Stage 3 facilitated both microalgal growth and [Formula: see text]-N removal, with average and maximum biomass productivity of 55.3 and 161.0 mg L(-1) d(-1), and corresponding removal rates of 4.2 and 15.0 mg L(-1) d(-1), respectively, superior to previously published results. Observations of intracellular compositions confirmed the optimum treatment strategy, discovering excellent starch accumulating property of strain UMN266 as well. Combination of bioethanol production with the proposed three-stage process using various real wastewater streams at corresponding stages was suggested for future application.

  8. Optimizing thermally grown oxide for thermal barrier coatings on TiAl components via fluorine treatment

    NASA Astrophysics Data System (ADS)

    Donchev, A.; Braun, R.; Schütze, M.

    2010-01-01

    Titanium aluminides suffer from non-protective mixed-oxide scale formation during high-temperature exposure in oxidizing environments, so that they cannot be used at temperatures above approximately 800° C for longer times without additional treatment. A fluorine treatment on γ-TiAl alloys leads to the formation of a pure protective alumina scale and allows their use at service temperatures above 800°C. This thermally grown aluminum oxide layer can be used for bonding ceramic thermal barrier coatings to the TiAl substrate. Zirconia topcoats deposited by electron-beam physical vapor deposition were very adherent to F-treated TiA samples during cyclic oxidation tests at 900 to 1,000°C. A separate bond coat is not needed in this case.

  9. Treatment by serum up-conversion nanoparticles in the fluoride matrix changes the mechanism of cell death and the elasticity of the membrane.

    PubMed

    Pleskova, Svetlana N; Gorshkova, Ekaterina N; Novikov, Viktor V; Solioz, Marc

    2016-11-01

    Nanoparticles are increasingly being used for treatment and diagnostic purposes, but their effects on cells is not fully understood. Here, the interaction of fluorescent up-conversion nanoparticles (UpC-NPs) with neutrophils was investigated by imaging and measurement of membrane-cytosceletal elasticity by atomic force microscopy. It was found that UpC-NPs induce the death of neutrophils mainly by necrosis, and to a smaller extent by a novel process called 'mummification'. Necrosis occurs by gradual loss of intracellular contents and nuclei, 45-110min after exposure to UpC-NPs. Mummification is apparent as an increase in the rigidity of the neutrophils' membrane and acquisition of a characteristic bumpy shape with numerous protrusions; this structure does not change during atomic force microscopy scanning. Coating UpC-NPs with protein by incubation with serum leads to (1) formation of nanoparticle aggregates in the nm and μm size range, (2) a reduction in toxicity, (3) reduced mummification of neutrophils, and (4) no significant reduction of the elasticity of the membrane-cytoskeletal complex of neutrophils 30min after exposure to coated UpC-NPs. The study shows that serum proteins greatly curb the toxicity of nanoparticles and reveals mummification as a novel mechanism of UpC-NP-induced cell death. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Laser Surface Treatment of Stellite 6 Coating Deposited by HVOF on 316L Alloy

    NASA Astrophysics Data System (ADS)

    Shoja-Razavi, Reza

    2016-07-01

    This research aimed to study the effects of laser glazing treatment on microstructure, hardness, and oxidation behavior of Stellite 6 coating deposited by high velocity oxygen fuel (HVOF) spraying. The as-sprayed Stellite 6 coating (ST-HVOF) was subjected to single-pass and multiple-pass laser treatments to achieve the optimum glazing parameters. Microstructural characterizations were performed by x-ray diffractometry and field emission scanning electron microscopy equipped with energy-dispersive spectroscopy. Two-step optimization showed that laser treatment at the power of 200 W with a scan rate of 4 mm/s causes a surface layer with a thickness of 208 ± 32 µm to be remelted, while the underlying layers retain the original ST-HVOF coating structure. The obtained sample (ST-Glazing) exhibited a highly dense and uniform structure with an extremely low porosity of ~0.3%, much lower than that of ST-HVOF coating (2.3%). The average microhardness of ST-Glazing was measured to be 519 Hv0.3 indicating a 17% decrease compared to ST-HVOF (625 Hv0.3) due to the residual stress relief and dendrite coarsening from submicron size to ~3.4 µm after laser treatment. The lowest oxidation mass gain was obtained for ST-Glazing by 2 mg/cm2 after 8 cycles at 900 °C indicating 52 and 84% improvement in oxidation resistance in comparison to ST-HVOF and bare 316L steel substrates, respectively.

  11. Ultrasonic elasticity determination of 45S5 Bioglass(®)-based scaffolds: influence of polymer coating and crosslinking treatment.

    PubMed

    Li, Wei; Pastrama, Maria-Ioana; Ding, Yaping; Zheng, Kai; Hellmich, Christian; Boccaccini, Aldo R

    2014-12-01

    Highly porous 45S5 Bioglass(®)-based scaffolds with interconnected pore structure are promising candidates for bone tissue engineering due to their bioactivity, biocompatibility, osteogenic and angiogenic effects. In the present study, to ensure the mechanical competence of the 45S5 Bioglass(®)-based scaffolds, their stiffness was adjusted by applying polymer coatings and further crosslinking treatment. A non-destructive ultrasonic technique was used to determine the stiffness of the scaffolds. The stiffness of uncoated scaffolds was shown to increase by applying polymer coatings, and a further increase was achieved by crosslinking the used polymer coatings. All uncoated and polymer-coated scaffolds were confirmed to exhibit stiffness values in the range of reported values in the literature for cancellous bone. A statistical evaluation of combined multiscale ultrasound-nanoindentation measurements indicated that the stiffness of the coated scaffold is directly dependent on the stiffness of the polymer coating.

  12. The effect of heat treatment on the morphology of D-Gun sprayed hydroxyapatite coatings.

    PubMed

    Erkmen, Z E

    1999-01-01

    In this study, the morphology of the Hydroxyapatite (HA) coatings sprayed on Ti alloy samples by Detonation Gun Spray (D-Gun) and the effect of aging before and after heat treatment in physiological solution were observed. Cross-sectional porosity and percentages of amorphous and crystal phase were measured using optical, electron microscopy, and X-ray diffraction analysis. Differential Thermogravimetric Analysis (DTA) was performed to estimate the glass-crystalline phase transformation temperatures. Heat-treatment at 300, 500, 700, 800 and 1200 degrees C were carried out to confirm DTA results. As a final analysis, the aging effect using Ringer's solution for 1 week on heat-treated and non-heat-treated samples was measured. It was observed that, in D-Gun sprayed samples, the cross-sectional porosity stayed in the accepted 5% range as reported for other spraying techniques.(1-5) On the other hand, surface porosity measured using the water immersion method remained in the conventional porosity limit of 15% for non-heat-treated samples. Heat-treatment had a small influence on the porosity while the crystallinity increased considerably; in addition, aging had little effect on HA crystallinity for heat treated samples. This work showed that D-gun sprayed HA coatings had lower porosity and better integrity than other coatings, due to which we can expect better performance during in vivo applications.

  13. Specialist inpatient treatment for severe motor conversion disorder: a retrospective comparative study.

    PubMed

    McCormack, Ruaidhri; Moriarty, John; Mellers, John D; Shotbolt, Paul; Pastena, Rosa; Landes, Nadine; Goldstein, Laura; Fleminger, Simon; David, Anthony S

    2014-08-01

    Gold standard protocols have yet to be established for the treatment of motor conversion disorder (MCD). There is limited evidence to support inpatient, multidisciplinary intervention in chronic, severe cases. To evaluate the characteristics and outcomes of MCD patients admitted to a specialist neuropsychiatric inpatient unit. All patients admitted to the Lishman Unit (years 2007-2011) with a diagnosis of MCD were included. Data relevant to characteristics and status with regard to mobility, activities of daily living (ADLs) and Modified Rankin Scale (MRS) score at admission and discharge were extracted. Thirty-three cases (78.8% female) were included; the median duration of illness was 48 months. In comparison with brain injury patients admitted to the same unit, more cases had histories of childhood sexual abuse (36.4%, n=12), premorbid non-dissociative mental illness (81.1%, n=27) and employment as a healthcare/social-care worker (45.5%, n=15). Cases showed significant improvements in MRS scores (p<0.001), mobility (p<0.001) and ADL (p=0.002) following inpatient treatment. Patients with severe, long-standing MCD can achieve significant improvements in functioning after admission to a neuropsychiatry unit. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Treatment of benign biliary leaks with transhepatic placement of coated self-expanding metallic stents.

    PubMed

    Páramo, M; García-Barquín, P; Carrillo, M; Millor Muruzábal, M; Vivas, I; Bilbao, J I

    To analyze the safety and efficacy of percutaneous placement of coated self-expanding metallic stents (SEMS) in patients with biliary leaks. This ethics committee at our center approved this study. We retrospectively reviewed all coated SEMS placed between October 2008 and September 2015. We analyzed patient-related factors such as the primary underlying disease, prior hepatic procedures, and clinical outcome. We evaluated the location, the number and type of leak (anastomotic or non-anastomotic), and the characteristics of the interventional procedure (number of stents deployed, location of the stents, technical success, and primary functionality). We recorded the complications registered. We studied 14 patients (11 men and 3 women). The mean follow-up period was 375.5 days (range 15-1920 days). Leaks were postsurgical in 12 patients. One patient developed an arteriobilioportal fistula. In another, the biliary leak occurred secondary to the rupture of the common bile duct after ERCP. A total of 23 coated SEMS were placed, including 21 Fluency(®) stents (Bard, Tempe, AZ, USA) and 2 Wallflex(®) stents (Boston Scientific, Galway, Republic of Ireland). The technical success of the procedure was considered total in 11 (78.6%) patients, partial in 2 (14.3%) patients, and null in 1 (7.2%) patient. The clinical outcome was good in 13 of the 14 patients. The mean period of primary functionality of the coated SEMS was 331 days (range 15-1920 days). No major complications were observed in 11 (78.6%) patients. Percutaneous placement of coated SEMS for the treatment of benign biliary leaks is safe and efficacious, with a high rate of technical and clinical success and a moderate rate of complications. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Electrochemical hydroxyapatite-cobalt ferrite nanocomposite coatings as well hyperthermia treatment of cancer.

    PubMed

    Abdel-Hamid, Z; Rashad, M M; Mahmoud, Salwa M; Kandil, A T

    2017-07-01

    The fabrication of hydroxyapatite-Co-ferrite nanocomposite coatings was performed on stainless steel by chronoamperometry technique. HA-CoFe2O4 nanocomposite films were characterized using X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometer (VSM). The results reveal that CoFe2O4 nanoparticles dispersed within the HA matrix have flake and strip shapes. The magnetic property of the nanocomposite was increased by increasing the concentration of CoFe2O4 and a good saturation magnetization value was found to be 20.6emu/g with 50% CoFe2O4. By comparing with pure CoFe2O4, the composite still retain moderate magnetization as well as its biocompatible characters. The specific absorption rate (SAR) values were altered according to the change in CoFe2O4 concentration and the maximum SAR value was 125W/g. The incorporation of CoFe2O4 nanoparticles with HA coating was increased the corrosion resistance of HA in simulated body fluid (SBF). The results indicated that HA-CoFe2O4 nanocomposite coating could be a promising surface treatment technique for stainless steel medical implants as well hyperthermia treatment of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The Effect of Post-Heat Treatment on Microstructure of 316L Cold-Sprayed Coatings and Their Corrosion Performance

    NASA Astrophysics Data System (ADS)

    Dikici, B.; Yilmazer, H.; Ozdemir, I.; Isik, M.

    2016-04-01

    The combined effects of process gases and post-heat treatment temperature on the microstructure of 316L cold-sprayed coatings on Al5052 substrates have been investigated in this study. The stainless steel coatings were subjected to heat treatment at four different temperatures (250, 500, 750, and 1000 °C) to study the effect of heat treatment. In addition, the corrosion performances of the coatings at different process temperatures have been compared using the potentiodynamic scanning technique. Microstructural characterization of the coatings was carried out using scanning and transmission electron microscopy and x-ray diffraction. The results of present study showed that cold-sprayed stainless steel coatings processed with helium exhibited higher corrosion resistance than those of coatings sprayed with nitrogen process gas. This could partially be attributed to the reduction in porosity level (4.9%) and improvement of particle-particle bonding. In addition, evaluation of the mechanical and microstructural properties of the coatings demonstrated that subsequent heat treatment has major influence on the deposited layers sprayed with He process gas.

  17. Laser and radiofrequency-induced hyperthermia treatment via gold-coated magnetic nanocomposites

    PubMed Central

    Elsherbini, Alsayed AM; Saber, Mahmoud; Aggag, Mohamed; El-Shahawy, Ahmed; Shokier, Hesham AA

    2011-01-01

    Introduction The current radiofrequency ablation technique requires invasive needle placement. On the other hand, most of the common photothermal therapeutic methods are limited by lack of accuracy of targeting. Gold and magnetic nanoparticles offer the potential to heat tumor tissue selectively at the cellular level by noninvasive interaction with laser and radiofrequency. Methods Gold nanospheres and gold-coated magnetic nanocomposites were used for inducing hyperthermia to treat subcutaneous Ehrlich carcinoma implanted in female mice. Results In mice treated with gold nanospheres, tumors continued to grow but at a slow rate. In contrast, more than 50% of the tumors treated with gold-coated magnetic nanocomposites completely disappeared. Conclusion This simple and noninvasive method shows great promise as a technique for selective magnetic photothermal treatment. PMID:22114479

  18. Post-treatment of Plasma-Sprayed Amorphous Ceramic Coatings by Spark Plasma Sintering

    NASA Astrophysics Data System (ADS)

    Chraska, T.; Pala, Z.; Mušálek, R.; Medřický, J.; Vilémová, M.

    2015-04-01

    Alumina-zirconia ceramic material has been plasma sprayed using a water-stabilized plasma torch to produce free standing coatings. The as-sprayed coatings have very low porosity and are mostly amorphous. The amorphous material crystallizes at temperatures above 900 °C. A spark plasma sintering apparatus has been used to heat the as-sprayed samples to temperatures above 900 °C to induce crystallization, while at the same time, a uniaxial pressure of 80 MPa has been applied to their surface. After such post-treatment, the ceramic samples are crystalline and have very low open porosity. The post-treated material exhibits high hardness and significantly increased flexural strength. The post-treated samples have a microstructure that is best described as nanocomposite with the very small crystallites embedded in an amorphous matrix.

  19. Conversational Skills Instruction for Communication Apprehension and Avoidance: Evaluation of a Treatment Program.

    ERIC Educational Resources Information Center

    Glaser, Susan R.; And Others

    1983-01-01

    Describes and evaluates a conversational skills program designed to teach apprehensive communicators how to develop comfortable and effective social behavior in a variety of interpersonal contexts. (PD)

  20. Effect of chitosan coating combined with postharvest calcium treatment on strawberry (Fragaria×ananassa) quality during refrigerated storage.

    PubMed

    Hernández-Muñoz, Pilar; Almenar, Eva; Valle, Valeria Del; Velez, Dinoraz; Gavara, Rafael

    2008-09-15

    Strawberries (Fragaria×ananassa Duch.) were coated with either 1% or 1.5% chitosan (CS) or chitosan combined with calcium gluconate (CaGlu). Following treatment, strawberries were stored at 10°C and 70±5% RH for one week. The effectiveness of the treatments in extending fruit shelf-life was evaluated by determining fungal decay, respiration rate, quality attributes and overall visual appearance. No sign of fungal decay was observed during the storage period for fruit coated with 1.5% CS (with or without the addition of CaGlu) or 1% CS+0.5% CaGlu. By contrast, 12.5% of the strawberries coated with 1% CS lacking calcium salt were infected after five days of storage. The chitosan coating reduced respiration activity, thus delaying ripening and the progress of fruit decay due to senescence. Chitosan coatings delayed changes in weight loss, firmness and external colour compared to untreated samples. Strawberries coated with 1.5% chitosan exhibited less weight loss and reduced darkening than did those treated with 1% chitosan, independently of the presence or absence of CaGlu. However, addition of calcium to the 1% chitosan solution increased the firmness of the fruit. Coated samples had greater visual acceptability than had untreated fruits. The addition of calcium gluconate to the chitosan coating formulation increased the nutritional value by incrementing the calcium content of the fruit. Copyright © 2008 Elsevier Ltd. All rights reserved.

  1. Impacts of tilling and covering treatments on the biosolids solar drying conversion from Class B to Class A

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate the effects of tillage and cover treatments of solar drying on the conversion of Class B treated sewage sludge to a Class A product. The experiments were performed over two years at Green Valley, Arizona in steel-constructed sand-filled drying beds of 1.0m...

  2. The Impact of AD Drug Treatments on Event-Related Potentials as Markers of Disease Conversion

    PubMed Central

    Chapman, Robert M.; Porsteinsson, Anton P.; Gardner, Margaret N.; Mapstone, Mark; McCrary, John W.; Sandoval, Tiffany C.; Guillily, Maria D.; Reilly, Lindsey A.; DeGrush, Elizabeth

    2013-01-01

    This paper investigates how commonly prescribed pharmacologic treatments for Alzheimer’s disease (AD) affect Event-Related Potential (ERP) biomarkers as tools for predicting AD conversion in individuals with Mild Cognitive Impairment (MCI). We gathered baseline ERP data from two MCI groups (those taking AD medications and those not) and later determined which subjects developed AD (Convert->AD) and which subjects remained cognitively stable (Stable). We utilized a previously developed and validated multivariate system of ERP components to measure medication effects among these four subgroups. Discriminant analysis produced classification scores for each individual as a measure of similarity to each clinical group (Convert->AD, Stable), and we found a large significant main Group effect but no main AD Medications effect and no Group by Medications interaction. This suggested AD medications have negligible influence on this set of ERP components as weighted markers of disease progression. These results provide practical information to those using ERP measures as a biomarker to identify and track AD in individuals in a clinical or research setting. PMID:23905997

  3. Within-Treatment Factors as Predictors of Outcomes Following Conversational Recasting

    PubMed Central

    Hassink, Johanna M.; Leonard, Laurence B.

    2013-01-01

    Purpose Although conversational recasting has been a generally successful treatment approach, the precise factors that influence children’s learning through recasts are not yet understood. In this study, we examined details of the child utterance – clinician utterance relationship that seemed likely to influence learning. Method Three measures were calculated from transcripts of recasting sessions with 17 preschoolers with specific language impairment. In all sessions, third person singular – s served as the target. The measures of interest were the frequency of recasts following child utterances that were prompted by clinicians, the frequency of clinicians’ recasts of subjectless sentences, and the frequency of clinicians’ noncorrective recasts. We assessed the short-term and long-term predictive value of these measures through regression analyses. Results Noncorrective recasts proved to be a positive predictor of short- and long-term gains in the use of the target form. Recasts of subjectless sentences were associated with poorer outcomes, though their contribution was relatively small. Conclusions The nature of learning that takes place varies according to the relationship between child and clinician utterances during the recasting process. These variations have implications for clinical practice and for how learning through recasting is characterized. PMID:20308290

  4. Rapid heat treatment for anatase conversion of titania nanotube orthopedic surfaces

    NASA Astrophysics Data System (ADS)

    Bhosle, Sachin M.; Friedrich, Craig R.

    2017-10-01

    The amorphous to anatase transformation of anodized nanotubular titania surfaces has been studied by x-ray diffraction and transmission electron microscopy (TEM). A more rapid heat treatment for conversion of amorphous to crystalline anatase favorable for orthopedic implant applications was demonstrated. Nanotube titania surfaces were fabricated by electrochemical anodization of Ti6Al4V in an electrolyte containing 0.2 wt% NH4F, 60% ethylene glycol and 40% deionized water. The resulting surfaces were systematically heat treated in air with isochronal and isothermal experiments to study the temperature and time dependent transformation respectively. Energy dispersive spectroscopy shows that the anatase phase transformation of TiO2 in the as-anodized amorphous nanotube layer can be achieved in as little as 5 min at 350 °C in contrast to reports of higher temperature and much longer time. Crystallinity analysis at different temperatures and times yield transformation rate coefficients and activation energy for crystalline anatase coalescence. TEM confirms the (101) TiO2 presence within the nanotubes. These results confirm that for applications where amorphous titania nanotube surfaces are converted to crystalline anatase, a 5 min production flow-through heating process could be used instead of a 3 h batch process, reducing time, cost, and complexity.

  5. Rapid heat treatment for anatase conversion of titania nanotube orthopedic surfaces.

    PubMed

    Bhosle, Sachin M; Friedrich, Craig R

    2017-10-06

    The amorphous to anatase transformation of anodized nanotubular titania surfaces has been studied by x-ray diffraction and transmission electron microscopy (TEM). A more rapid heat treatment for conversion of amorphous to crystalline anatase favorable for orthopedic implant applications was demonstrated. Nanotube titania surfaces were fabricated by electrochemical anodization of Ti6Al4V in an electrolyte containing 0.2 wt% NH4F, 60% ethylene glycol and 40% deionized water. The resulting surfaces were systematically heat treated in air with isochronal and isothermal experiments to study the temperature and time dependent transformation respectively. Energy dispersive spectroscopy shows that the anatase phase transformation of TiO2 in the as-anodized amorphous nanotube layer can be achieved in as little as 5 min at 350 °C in contrast to reports of higher temperature and much longer time. Crystallinity analysis at different temperatures and times yield transformation rate coefficients and activation energy for crystalline anatase coalescence. TEM confirms the (101) TiO2 presence within the nanotubes. These results confirm that for applications where amorphous titania nanotube surfaces are converted to crystalline anatase, a 5 min production flow-through heating process could be used instead of a 3 h batch process, reducing time, cost, and complexity.

  6. Chitosan coating to enhance the therapeutic efficacy of calcium sulfate-based antibiotic therapy in the treatment of chronic osteomyelitis

    PubMed Central

    Beenken, Karen E; Smith, James K; Skinner, Robert A; Mclaren, Sandra G; Bellamy, William; Gruenwald, M Johannes; Spencer, Horace J; Jennings, Jessica A; Haggard, Warren O; Smeltzer, Mark S

    2014-01-01

    We demonstrate that coating calcium sulfate with deacetylated chitosan enhances the elution profile of daptomycin by prolonging the period during which high concentrations of antibiotic are released. Coatings reduced initial bolus release of daptomycin by a factor of 10 to approximately 1000 μg/ml, and levels remained above 100 μg/ml for up to 10 days. Chitosan-coated and uncoated calcium sulfate implants with and without 15% daptomycin were evaluated in an experimental model of staphylococcal osteomyelitis through bacteriology scores, radiology, histopathology, and Gram staining. Significant reduction in bacteriology scores was observed for implants containing daptomycin and coated with chitosan compared with all the other groups. We confirm that the use of chitosan-coated calcium sulfate beads for local antibiotic delivery can be correlated with an improved therapeutic outcome following surgical debridement in the treatment of chronic osteomyelitis. PMID:24854984

  7. Chitosan coating to enhance the therapeutic efficacy of calcium sulfate-based antibiotic therapy in the treatment of chronic osteomyelitis.

    PubMed

    Beenken, Karen E; Smith, James K; Skinner, Robert A; Mclaren, Sandra G; Bellamy, William; Gruenwald, M Johannes; Spencer, Horace J; Jennings, Jessica A; Haggard, Warren O; Smeltzer, Mark S

    2014-10-01

    We demonstrate that coating calcium sulfate with deacetylated chitosan enhances the elution profile of daptomycin by prolonging the period during which high concentrations of antibiotic are released. Coatings reduced initial bolus release of daptomycin by a factor of 10 to approximately 1000 µg/ml, and levels remained above 100 µg/ml for up to 10 days. Chitosan-coated and uncoated calcium sulfate implants with and without 15% daptomycin were evaluated in an experimental model of staphylococcal osteomyelitis through bacteriology scores, radiology, histopathology, and Gram staining. Significant reduction in bacteriology scores was observed for implants containing daptomycin and coated with chitosan compared with all the other groups. We confirm that the use of chitosan-coated calcium sulfate beads for local antibiotic delivery can be correlated with an improved therapeutic outcome following surgical debridement in the treatment of chronic osteomyelitis. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma

    PubMed Central

    Zhang, Weixing; Cai, Xiaobo; Chen, Dafan; Wan, Xinjian

    2016-01-01

    125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost. PMID:26840346

  9. Comparing Two Antibacterial Treatments for Bioceramic Coatings at Short Culture Times

    NASA Astrophysics Data System (ADS)

    Melero, H.; Madrid, C.; Fernández, J.; Guilemany, J. M.

    2014-04-01

    Plasma-sprayed hydroxyapatite coatings were employed industrially for decades to improve osteointegration of articular implants, but many studies have warned about the problems inherent to this procedure (mechanical properties, harmful phases). Consequently, a combination of hydroxyapatite with TiO2 sprayed by high velocity oxy-fuel spray was considered in this study. As infection after joint replacement surgery is one of the most critical concerns when considering implant performance, it is necessary to study possible ways to reduce or eliminate it. Two coating treatments were chosen for this study: addition of a percentage of ZnO and immersion in gentamicin for 24 h. Furthermore, three bacteria were considered: Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The evolution of bacteria viability in solution was measured at 0, 2, and 4 h; and plate assays were performed to study antibacterial effects by diffusion. The results show an important antibacterial effect of the as-sprayed coating, attributed to the presence of -OH radicals on the surface. The presence of ZnO did not have any additional influence on bacteria viability, but gentamicin-treated samples showed an improvement in antibacterial behavior for Gram-negative bacteria in solution, as well as a bactericidal effect in diffusion conditions.

  10. Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma.

    PubMed

    Lin, Lizhou; Guo, Lili; Zhang, Weixing; Cai, Xiaobo; Chen, Dafan; Wan, Xinjian

    2016-01-01

    125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost.

  11. Effect of current mode on PEO treatment of magnesium in Ca- and P-containing electrolyte and resulting coatings

    NASA Astrophysics Data System (ADS)

    Gao, Yonghao; Yerokhin, Aleksey; Matthews, Allan

    2014-10-01

    Plasma electrolytic oxidation (PEO) coatings were produced on commercially pure magnesium in a biologically friendly electrolyte composed of 2 g L-1 Ca(OH)2 and 12 g L-1 Na3PO4·12H2O using pulsed unipolar and bipolar current regimes with negative biasing varying from 0 to 20 mA cm-2. Analysis of voltage transients was performed to characterise the PEO processes. The coating morphology and phase composition were studied by scanning electron microscopy and X-ray diffraction technique, respectively. In vitro corrosion performance of the coatings was evaluated in a simulated body fluid at 37 ± 1 °C, using electrochemical techniques including open circuit potential monitoring, electrochemical impedance spectroscopy and potentiodynamic polarisation scans. The influence of the negative biasing on the PEO process and resulting coating characteristics is discussed. Unlike generally recognised beneficial effects of the negative biasing in PEO treatments of some other metal-electrolyte systems, it was found that detrimental effects are induced to the coatings on cp-Mg produced in the studied electrolyte when the negative current amplitude increases, which may be attributed to hydrogen liberation at the coating/substrate interface during the negative biasing cycles. As a result, a deterioration of vitro corrosion performance was observed for the pulsed bipolar PEO coatings compared to those produced using the pulsed unipolar regime which provides better quality coatings.

  12. Effects of combined treatments of irradiation and antimicrobial coatings on reduction of food pathogens in broccoli florets

    NASA Astrophysics Data System (ADS)

    Takala, P. N.; Salmieri, S.; Vu, K. D.; Lacroix, M.

    2011-12-01

    The effect of combined treatment of antimicrobial coatings and γ-radiation on reduction of food pathogens such as Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium was evaluated in broccoli florets. Broccoli florets were inoculated with pathogenic bacteria at 10 6 CFU/g. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids (OAs) plus lactic acid bacteria metabolites (LABs), OA plus citrus extract (CE), OA plus CE plus spice mixture (SM), and OA plus rosemary extract (RE). Coated florets were irradiated with various doses (0-3.3 kGy), and microbial analyses were used to calculate the D10 value and radiosensitive relative. The coating containing OA plus CE was the most effective formulation for increasing the sensitization of Escherichia coli by 2.4 times as compared to the control without the antimicrobial coating. For Salmonella Typhimurium, coating containing OA plus LAB was the most effective formulation, increasing radiosensitivity by 2.4 times as well. All antimicrobial coatings had almost the same effect of increasing the sensitivity of Listeria monocytogenes (from 1.31 to 1.45 times) to γ-irradiation.

  13. Oral 5-fluorouracil colon-specific delivery through in vivo pellet coating for colon cancer and aberrant crypt foci treatment.

    PubMed

    Bose, A; Elyagoby, A; Wong, T W

    2014-07-01

    In situ coating of 5-fluorouracil pellets by ethylcellulose and pectin powder mixture (8:3 weight ratio) in capsule at simulated gastrointestinal media provides colon-specific drug release in vitro. This study probes into pharmacodynamic and pharmacokinetic profiles of intra-capsular pellets coated in vivo in rats with reference to their site-specific drug release outcomes. The pellets were prepared by extrusion-spheronization technique. In vitro drug content, drug release, in vivo pharmacokinetics, local colonic drug content, tumor, aberrant crypt foci, systemic hematology and clinical chemistry profiles of coated and uncoated pellets were examined against unprocessed drug. In vivo pellet coating led to reduced drug bioavailability and enhanced drug accumulation at colon (179.13 μg 5-FU/g rat colon content vs 4.66 μg/g of conventional in vitro film-coated pellets at 15 mg/kg dose). The in vivo coated pellets reduced tumor number and size, through reforming tubular epithelium with basement membrane and restricting expression of cancer from adenoma to adenocarcinoma. Unlike uncoated pellets and unprocessed drug, the coated pellets eliminated aberrant crypt foci which represented a putative preneoplastic lesion in colon cancer. They did not inflict additional systemic toxicity. In vivo pellet coating to orally target 5-fluorouracil delivery at cancerous colon is a feasible therapeutic treatment approach.

  14. The evolving role of drug-coated balloons for the treatment of complex femoropopliteal lesions.

    PubMed

    Korosoglou, Grigorios; Lichtenberg, Michael; Celik, Sultan; Andrassy, Joachim; Brodmann, Marianne; Andrassy, Martin

    2017-10-02

    Conventional therapies for transcatheter treatment of patients with infrainguinal obstructive disease remain compromised by high restenosis rates. Drug-coated balloons (DCB) offer a novel therapeutic alternative targeting the source of neo-intimal hyperplasia, without the need for a permanent endovascular scaffold and their inherent limitations. A systematic research of the medical databases (Pubmed) has been conducted for this up-to-date review. Keywords, such as "drug-coated balloons (DCB), "drug-eluting balloon (DEB), "in-stent-restenosis" (ISR), "de novo stenosis", "plain old angioplasty" (POBA), "atherectomy", "debulking", "superficial femoral artery" (SFA), "popliteal artery" (PA), "above/below the knee" and "peripheral artery disease" (PAD) have been used. Furthermore, data from reviews, original contributions, randomized controlled studies, observational studies, registries and single center experiences have been considered. Overall, an increasing level of evidence supports the use of DCB for the treatment of long, complex, heavily calcified femoropopliteal non-occlusive and occlusive lesions, including failure after BM stent implantation due to ISR. However, more studies will be necessary to investigate the long term effects of DCB-treatment in these real world lesions.

  15. Fabrication of TiO2 Crystalline Coatings by Combining Ti-6Al-4V Anodic Oxidation and Heat Treatments

    PubMed Central

    Schvezov, Carlos Enrique; Ares, Alicia Esther

    2015-01-01

    The bio- and hemocompatibility of titanium alloys are due to the formation of a TiO2 layer. This natural oxide may have fissures which are detrimental to its properties. Anodic oxidation is used to obtain thicker films. By means of this technique, at low voltages oxidation, amorphous and low roughness coatings are obtained, while, above a certain voltage, crystalline and porous coatings are obtained. According to the literature, the crystalline phases of TiO2, anatase, and rutile would present greater biocompatibility than the amorphous phase. On the other hand, for hemocompatible applications, smooth and homogeneous surfaces are required. One way to obtain crystalline and homogeneous coatings is by heat treatments after anodic oxidation. The aim of this study is to evaluate the influence of heat treatments on the thickness, morphology, and crystalline structure of the TiO2 anodic coatings. The characterization was performed by optical and scanning electron microscopy, X-ray diffraction, and X-ray reflectometry. Coatings with different colors of interference were obtained. There were no significant changes in the surface morphology and roughness after heat treatment of 500°C. Heat treated coatings have different proportions of the crystalline phases, depending on the voltage of anodic oxidation and the temperature of the heat treatment. PMID:25784939

  16. Fabrication of TiO2 Crystalline Coatings by Combining Ti-6Al-4V Anodic Oxidation and Heat Treatments.

    PubMed

    Vera, María Laura; Rosenberger, Mario Roberto; Schvezov, Carlos Enrique; Ares, Alicia Esther

    2015-01-01

    The bio- and hemocompatibility of titanium alloys are due to the formation of a TiO2 layer. This natural oxide may have fissures which are detrimental to its properties. Anodic oxidation is used to obtain thicker films. By means of this technique, at low voltages oxidation, amorphous and low roughness coatings are obtained, while, above a certain voltage, crystalline and porous coatings are obtained. According to the literature, the crystalline phases of TiO2, anatase, and rutile would present greater biocompatibility than the amorphous phase. On the other hand, for hemocompatible applications, smooth and homogeneous surfaces are required. One way to obtain crystalline and homogeneous coatings is by heat treatments after anodic oxidation. The aim of this study is to evaluate the influence of heat treatments on the thickness, morphology, and crystalline structure of the TiO2 anodic coatings. The characterization was performed by optical and scanning electron microscopy, X-ray diffraction, and X-ray reflectometry. Coatings with different colors of interference were obtained. There were no significant changes in the surface morphology and roughness after heat treatment of 500°C. Heat treated coatings have different proportions of the crystalline phases, depending on the voltage of anodic oxidation and the temperature of the heat treatment.

  17. Effects of post-heat treatment on microstructure and properties of laser cladded composite coatings on titanium alloy substrate

    NASA Astrophysics Data System (ADS)

    Li, G. J.; Li, J.; Luo, X.

    2015-01-01

    The composite coatings were produced on the Ti6Al4V alloy substrate by laser cladding. Subsequently, the coatings were heated at 500 °C for 1 h and 2 h and then cooled in air. Effects of post-heat treatment on microstructure, microhardness and fracture toughness of the coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), optical microscopy (OM). Wear resistance of the coatings was evaluated under the dry sliding reciprocating friction condition at room temperature. The results indicated that the coatings mainly consist of a certain amount of coarse white equiaxed WC particles surrounded by the white-bright W2C, a great deal of fine dark spherical TiC particles and the matrix composed of the α(Ti), Ti2Ni and TiNi phases. Effects of the post-heat treatment on phase constituents and microstructure of the coatings were almost negligible due to the low temperature. However, the post-heat treatment could decrease the residual stress and increase fracture toughness of the coatings, and fracture toughness of the coatings was improved from 2.77 MPa m1/2 to 3.80 MPa m1/2 and 4.43 MPa m1/2 with the heat treatment for 1 h and 2 h, respectively. The mutual role would contribute to the reduction in cracking susceptibility. Accompanied with the increase in fracture toughness, microhardness of the coatings was reduced slightly. The dominant wear mechanism for all the coatings was abrasive wear, characterized by micro-cutting or micro-plowing. The heat treatment could significantly decrease the average friction coefficient and reduce the fluctuation of the friction coefficient with the change in sliding time. The appropriate heat treatment time (approximately 1 h) had a minimal effect on wear mass loss and volume loss. Moreover, the improvement in fracture toughness will also be beneficial to wear resistance of the coatings under the long service.

  18. The effect of honey-coated bandages compared with silver-coated bandages on treatment of malignant wounds-a randomized study.

    PubMed

    Lund-Nielsen, Betina; Adamsen, Lis; Kolmos, Hans Jørn; Rørth, Mikael; Tolver, Anders; Gottrup, Finn

    2011-11-01

    Malignant wounds (MWs) occur in 5-10% of all cancer patients. Malodor and exudation are the most common side effects. The aim was to determine the influence of honey-coated compared with silver-coated bandages on treatment of MWs. Patients were randomly selected to enter either group A (honey-coated bandages) or group B (silver-coated bandages). Parameters were the following: wound size, cleanliness, malodor, exudation, and wound pain. Digital photographs, visual analog scales (VAS), and wound morphology registration were used for measurement at baseline and following the 4-week intervention. Sixty-nine patients with MWs and advanced cancer, aged 47-90 (median 65.6), were included. No statistically significant difference was noted between the groups with respect to wound size, degree of cleanliness, exudation, malodor, and wound pain. There was a median decrease in wound size of 15 cm² and 8 cm² in group A and B, respectively (p = 0.63). Based on post-intervention pooled data from the groups, improvement was seen in 62% of the participants with respect to wound size and in 58% (n = 69) with respect to cleanliness. The VAS score for malodor (p = 0.007) and exudation (p < 0.0001) improved significantly post-intervention. Patients with reduced wound size had a median survival time of 387 days compared with 134 days in patients with no wound reduction (p = 0.003). The use of honey-coated and silver-coated bandages improved the outcome of MWs. No differences were found between the two regimens. Both types of bandages are recommended for use by patients with MWs containing tumor debris and necrosis.

  19. Electrostatic interactions between the CTX phage minor coat protein and the bacterial host receptor TolA drive the pathogenic conversion of Vibrio cholerae.

    PubMed

    Houot, Laetitia; Navarro, Romain; Nouailler, Matthieu; Duché, Denis; Guerlesquin, Françoise; Lloubes, Roland

    2017-08-18

    Vibrio cholerae is a natural inhabitant of aquatic environments and converts to a pathogen upon infection by a filamentous phage, CTXΦ, that transmits the cholera toxin-encoding genes. This toxigenic conversion of V. cholerae has evident implication in both genome plasticity and epidemic risk, but the early stages of the infection have not been thoroughly studied. CTXΦ transit across the bacterial periplasm requires binding between the minor coat protein named pIII and a bacterial inner-membrane receptor, TolA, which is part of the conserved Tol-Pal molecular motor. To gain insight into the TolA-pIII complex, we developed a bacterial two-hybrid approach, named Oxi-BTH, suited for studying the interactions between disulfide bond-folded proteins in the bacterial cytoplasm of an Escherichia coli reporter strain. We found that two of the four disulfide bonds of pIII are required for its interaction with TolA. By combining Oxi-BTH assays, NMR, and genetic studies, we also demonstrate that two intermolecular salt bridges between TolA and pIII provide the driving forces of the complex interaction. Moreover, we show that TolA residue Arg-325 involved in one of the two salt bridges is critical for proper functioning of the Tol-Pal system. Our results imply that to prevent host evasion, CTXΦ uses an infection strategy that targets a highly conserved protein of Gram-negative bacteria essential for the fitness of V. cholerae in its natural environment. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Advanced characterization study of commercial conversion and electrocoating structures on magnesium alloys AZ31B and ZE10A

    DOE PAGES

    Brady, Michael P.; Leonard, Donovan N.; Meyer, III, Harry M.; ...

    2016-03-31

    The local metal-coating interface microstructure and chemistry formed on commercial magnesium alloys Mg–3Al–1Zn (AZ31B) and Mg–1Zn–0.25Zr–<0.5Nd (ZE10A, ZEK100 type) were analyzed as-chemical conversion coated with a commercial hexafluoro-titanate/zirconate type + organic polymer based treatment (Bonderite® 5200) and a commercial hexafluoro-zirconate type + trivalent chromium Cr3 + type treatment (Surtec® 650), and after the same conversion coatings followed by electrocoating with an epoxy based coating, Cathoguard® 525. Characterization techniques included scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cross-section scanning transmission electron microscopy (STEM). Corrosion behavior was assessed in room temperature saturated aqueous Mg(OH)2 solution with 1 wt.% NaCl. Themore » goal of the effort was to assess the degree to which substrate alloy additions become enriched in the conversion coating, and how the conversion coating was impacted by subsequent electrocoating. Key findings included the enrichment of Al from AZ31B and Zr from ZE10A, respectively, into the conversion coating, with moderate corrosion resistance benefits for AZ31B when Al was incorporated. Varying degrees of increased porosity and modification of the initial conversion coating chemistry at the metal-coating interface were observed after electrocoating. These changes were postulated to result in degraded electrocoating protectiveness. As a result, these observations highlight the challenges of coating Mg, and the need to tailor electrocoating in light of potential degradation of the initial as-conversion coated Mg alloy surface.« less

  1. Advanced characterization study of commercial conversion and electrocoating structures on magnesium alloys AZ31B and ZE10A

    SciTech Connect

    Brady, Michael P.; Leonard, Donovan N.; Meyer, III, Harry M.; Song, Guang -Ling; Kitchen, Kris; Davis, Bruce; Thompson, J. K.; Unocic, K. A.; Elsentriecy, H. H.

    2016-03-31

    The local metal-coating interface microstructure and chemistry formed on commercial magnesium alloys Mg–3Al–1Zn (AZ31B) and Mg–1Zn–0.25Zr–<0.5Nd (ZE10A, ZEK100 type) were analyzed as-chemical conversion coated with a commercial hexafluoro-titanate/zirconate type + organic polymer based treatment (Bonderite® 5200) and a commercial hexafluoro-zirconate type + trivalent chromium Cr3 + type treatment (Surtec® 650), and after the same conversion coatings followed by electrocoating with an epoxy based coating, Cathoguard® 525. Characterization techniques included scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cross-section scanning transmission electron microscopy (STEM). Corrosion behavior was assessed in room temperature saturated aqueous Mg(OH)2 solution with 1 wt.% NaCl. The goal of the effort was to assess the degree to which substrate alloy additions become enriched in the conversion coating, and how the conversion coating was impacted by subsequent electrocoating. Key findings included the enrichment of Al from AZ31B and Zr from ZE10A, respectively, into the conversion coating, with moderate corrosion resistance benefits for AZ31B when Al was incorporated. Varying degrees of increased porosity and modification of the initial conversion coating chemistry at the metal-coating interface were observed after electrocoating. These changes were postulated to result in degraded electrocoating protectiveness. As a result, these observations highlight the challenges of coating Mg, and the need to tailor electrocoating in light of potential degradation of the initial as-conversion coated Mg alloy surface.

  2. Surface Treatments for Improved Performance of Spinel-coated AISI 441 Ferritic Stainless Steel

    SciTech Connect

    Stevenson, Jeffry W.; Riel, Eric M.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2013-01-01

    Ferritic stainless steels are promising candidates for IT-SOFC interconnect applications due to their low cost and resistance to oxidation at SOFC operating temperatures. However, steel candidates face several challenges; including long term oxidation under interconnect exposure conditions, which can lead to increased electrical resistance, surface instability, and poisoning of cathodes due to volatilization of Cr. To potentially extend interconnect lifetime and improve performance, a variety of surface treatments were performed on AISI 441 ferritic stainless steel coupons prior to application of a protective spinel coating. The coated coupons were then subjected to oxidation testing at 800 and 850°C in air, and electrical testing at 800°C in air. While all of the surface-treatments resulted in improved surface stability (i.e., increased spallation resistance) compared to untreated AISI 441, the greatest degree of improvement (through 20,000 hours of testing at 800°C and 14,000 hours of testing at 850°C) was achieved by surface blasting.

  3. Controllable preparation of a nano-hydroxyapatite coating on carbon fibers by electrochemical deposition and chemical treatment.

    PubMed

    Wang, Xudong; Zhao, Xueni; Wang, Wanying; Zhang, Jing; Zhang, Li; He, Fuzhen; Yang, Jianjun

    2016-06-01

    A nano-hydroxyapatite (HA) coating with appropriate thickness and morphology similar to that of human bone tissue was directly prepared onto the surfaces of carbon fibers (CFs). A mixed solution of nitric acid, hydrochloric acid, sulfuric acid, and hydrogen peroxide (NHSH) was used in the preparation process. The coating was fabricated by combining NHSH treatment and electrochemical deposition (ECD). NHSH treatment is easy to operate, produces rapid reaction, and highly effective. This method was first used to induce the nucleation and growth of HA crystals on the CF surfaces. Numerous O-containing functional groups, such as hydroxyl (-OH) and carboxyl (-COOH) groups, were grafted onto the CF surfaces by NHSH treatment (NHSH-CFs); as such, the amounts of these groups on the functionalized CFs increased by nearly 8- and 12-fold, respectively, compared with those on untreated CFs. After treatment, the NHSH-CFs not only acquired larger specific surface areas but retained surfaces free from serious corrosion or breakage. Hence, NHSH-CFs are ideal depositional substrates of HA coating during ECD. ECD was successfully used to prepare a nano-rod-like HA coating on the NHSH-CF surfaces. The elemental composition, structure, and morphology of the HA coating were effectively controlled by adjusting various technological parameters, such as the current density, deposition time, and temperature. The average central diameter of HA crystals and the coating density increased with increasing deposition time. The average central diameter of most HA crystals on the NHSH-CFs varied from approximately 60 nm to 210 nm as the deposition time increased from 60 min to 180 min. Further studies on a possible deposition mechanism revealed that numerous O-containing functional groups on the NHSH-CF surfaces could associate with electrolyte ions (Ca(2+)) to form special chemical bonds. These bonds can induce HA coating deposition and improve the interfacial bonding strength between the HA

  4. Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response.

    PubMed

    Shi, Xingling; Xu, Lingli; Munar, Melvin L; Ishikawa, Kunio

    2015-04-01

    Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant-gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl2 solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120°C was the critical temperature for the hydrothermal treatment condition. Treatment below 120°C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Taste masking of bitter drug powder without loss of bioavailability by heat treatment of wax-coated microparticles.

    PubMed

    Sugao, H; Yamazaki, S; Shiozawa, H; Yano, K

    1998-01-01

    Indeloxazine hydrochloride (IDX), a cerebral activator, has a bitter astringent taste. To prepare powders of IDX without this bitter taste, microparticles (median diameter, 130 microns) of IDX were coated with a mixture comprising hydrogenated oil and surfactants in a fluidized bed using the side-spray method. Drug release from the resulting coated particles was significantly delayed. Dissolution rate was remarkably enhanced, however, by heat-treating the coated particles at a temperature above the melting point of the surfactant in the coated layer. The results of differential scanning calorimetry measurements show that part of the surfactant in the coated layer exists separately. Further, surface changes in the coated layer before and after heat treatment showed that this enhancement of dissolution rate was due to rediffusion of the surfactant in the coated layer followed by melting of the surfactant. This effect allows the design of powders of IDX which release the drug quickly and with bioequivalence to the commercial IDX 20 mg tablets while sufficiently suppressing the bitter taste.

  6. Effect of pH, Surfactant, and Heat Treatment on Morphology, Structure, and Hardness of Electrodeposited Co-P Coatings

    NASA Astrophysics Data System (ADS)

    Zeinali-Rad, M.; Allahkaram, S. R.; Mahdavi, S.

    2015-09-01

    Nano-crystalline and amorphous Co-P coatings were deposited on plain carbon steel substrates by using direct current. Effects of electrolyte pH on morphology, current efficiency, phosphorus content, hardness, and preferred orientation of the nano-crystalline coatings were investigated. Moreover, the effects of heat treatment on microstructure and hardness of the nano-crystalline and the amorphous coatings were studied. The results showed that, phosphorus content and hardness of the nano-crystalline coatings were decreased by increasing of the pH, in spite of a current efficiency enhancement to as much as 98%. Grain size and preferred orientation were also changed from 13 to 31 nm and from mostly [002] to [100] by increasing the pH from 1 to 4, respectively. Smoother coatings and higher current efficiencies were obtained by the addition of 1 g/L sodium dodecyl sulfate (SDS) to the bath. Highest hardness of the nano-crystalline and the amorphous coatings was about 600 and 750 HV, which increased and reached 760 and 1090 HV after heat treatment, respectively.

  7. Preparation of visible-light-responsive TiO2 coatings using molten KNO3 treatment and their photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Hao, Liang; Guan, Sujun; Takaya, Shunsuke; Yoshida, Hiroyuki; Tochihara, Misako; Lu, Yun

    2017-06-01

    In this work, the process of mechanical coating followed by molten KNO3 treatment is given to prepare visible-light-responsive K+-doped TiO2. X-ray diffraction (XRD), scanning electron spectroscopy (SEM), Energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) were conducted to characterize these TiO2 coatings. The results showed that K+-doped anatase TiO2/Ti composite coatings formed after molten KNO3 treatment at elevated temperatures. Meanwhile, their photocatalytic degradation of methylene blue (MB) and the antibacterial activity against Escherichia coli (E. coli) was also studied. The visible-light-responsive photocatalytic activity of the coatings in MB degradation increased with increase of K+ ions when holding temperature was raised from 673 to 773 K. An excellent antibacterial activity of the K+-doped TiO2/Ti coatings against E. coli was also obtained even in absence of light. The antibacterial activity in dark should attribute to the release of K+ ions from the coatings. The photocatalytic activity under visible-light irradiation should result from the absorption spectrum extension due to the doping of K+ ions into the lattice of TiO2.

  8. Treatment of post-transplantation lymphoproliferative disorders after kidney transplant with rituximab and conversion to m-TOR inhibitor.

    PubMed Central

    Nieto-Rios, John Fredy; Gómez de los Ríos, Sandra Milena; Ocampo-Kohn, Catalina; Aristizabal-Alzate, Arbey; Gálvez-Cárdenas, Kenny Mauricio; Zuluaga-Valencia, Gustavo Adolfo

    2016-01-01

    Abstract Background: Post-transplantation lymphoproliferative disorders are serious complications of organ transplantation which treatment is not yet standardized. Objective: To describe the clinical response, overall and graft survival of patients in our center with this complication after kidney transplantation, which received rituximab as part of their treatment as well as conversion to m-TOR. Methods: Retrospective study, which included patients, diagnosed with post-transplant lymphoproliferative disorders after kidney transplantation from January 2011 to July 2014. Results: Eight cases were found with a wide spectrum of clinical presentations. Most had monomorphic histology, 85% were associated with Epstein-Barr virus, 25% of patients had tumor involvement of the renal graft, and 12.5% ​​had primary central nervous system lymphoma. All patients were managed with reduction of immunosuppression, conversion to m-TOR (except one who lost the graft at diagnosis) and rituximab-based therapy. The overall response rate was 87.5% (62.5% complete response, 25% partial response). Survival was 87.5% with a median follow-up of 34 months. An additional patient lost the graft, with chronic nephropathy already known. All the remaining patients had stable renal function. Conclusions: There are no standardized treatment regimens for lymphoproliferative disorders after kidney transplantation, but these patients can be managed successfully with reduction of immunosuppression, conversion to m-TOR and rituximab-based schemes. PMID:28293043

  9. Protective effect of resin coating on the microleakage of Class V restorations following treatment with carbamide peroxide in vitro.

    PubMed

    Yu, Hao; Li, Qing; Attin, Thomas; Wang, Yining

    2010-01-01

    This in vitro study evaluated the effects of a resin coating on the microleakage of Class V restorations due to bleaching. One-hundred and sixty Class V cavities were randomly restored with one of four different restorative materials (n = 40): a compomer (Dyract AP), a conventional glass-ionomer cement (Ketac Molar Easymix), a resin modified glass-ionomer cement (Fuji II LC) and a resin composite (Filtek Z350). For each kind of material, 40 restorations were divided into four subgroups: bleached with resin coating (group BC), bleached without resin coating (group B), immersed in artificial saliva with resin coating (group SC), immersed in artificial saliva without resin coating (group S). In groups B and BC, the specimens were bleached with 10% carbamide peroxide gel for eight hours daily, while groups SC and S were stored in artificial saliva instead. After 28-day treatment, all the samples were subjected to a dye penetration test using the multiple-sectioning technique. In addition, one more test was performed to investigate the color difference between the coated and uncoated tooth surface after bleaching. There was a statistically significant increase in cervical microleakage in the group B specimens of Fuji II LC and Ketac Molar Easymix compared to their respective control specimen (group S). These effects on microleakage were not found in the bleached specimens with resin coating (group BC). There was also no visually-detectable color difference between the coated and uncoated tooth surface. In conclusion, resin coating is an effective method for avoiding the bleaching-induced microleakage of glass-ionomer cement.

  10. Maleic acid treatment of bioabated corn stover liquors improves cellulose conversion to ethanol

    USDA-ARS?s Scientific Manuscript database

    Elimination of inhibitory compounds released during pretreatment of lignocellulose is critical for efficient cellulose conversion and ethanol fermentation. This study examined the effect of bioabated liquor from pretreated corn stover on enzyme hydrolysis of Solka Floc or pretreated corn stover soli...

  11. Curcumin-Loaded Chitosan-Coated Nanoparticles as a New Approach for the Local Treatment of Oral Cavity Cancer.

    PubMed

    Mazzarino, Leticia; Loch-Neckel, Gecioni; Bubniak, Lorena Dos Santos; Mazzucco, Suelen; Santos-Silva, Maria Cláudia; Borsali, Redouane; Lemos-Senna, Elenara

    2015-01-01

    Mucoadhesive nanoparticles loaded with curcumin were developed as a new approach to deliver curcumin for the local treatment of oral cancer. PCL nanoparticles coated with chitosan displaying different molar masses were prepared by using the nanoprecipitation technique. The mucoadhesive properties of nanoparticle suspensions were demonstrated by their strong ability to interact with the glycoprotein mucin through electrostatic interactions. Similar permeation profiles of curcumin loaded in uncoated and chitosan-coated nanoparticles across porcine esophageal mucosa were verified. Curcumin concentrations retained in the mucosa suggest the possibility of a local effect of the drug. In vitro studies demonstrated that free curcumin.and curcumin loaded into nanoparticles coated with chitosan caused significant reduction of SCC-9 human oral cancer cell viability in a concentration and time-dependent manner. However, no significant cell death was observed after 24 h of treatment with unloaded nanoparticles coated with chitosan. In addition, curcumin-loaded nanoparticles showed reduced cytotoxicity, when compared with the free drug. Therefore, chitosan-coated PCL nanoparticles may be considered a promising strategy to deliver curcumin directly into the oral cavity for the treatment of oral cancer.

  12. The structure and composition of chromate conversion coatings formed on aluminum-copper alloy AA2024-T3 and thin film analogs of constituent intermetallic compounds

    NASA Astrophysics Data System (ADS)

    Vasquez, Marvin Jaime

    2002-01-01

    A comprehensive suite of spectroscopy have been used to study the composition and structure of Chromate Conversion Coatings (CCC) formed on Aluminum Copper (Al-Cu) alloy AA2024-T3 and constituent Intermetallic Compounds (IMCs). Based on previous work the CCC formed over the IMCs is expected to be thinner and therefore different in structure and composition than the CCC formed on the matrix. The formation of the CCC over the different IMCs is expected to be dependent on the chemistry and the interaction of the IMCs with accelerators such as ferricyanide. Surface chemical and structural data determined by X-ray Photoelectron Spectroscopy (XPS), Synchrotron Infrared Microspectroscopy, X-ray Absorption Near Edge Spectroscopy (XANES), Extended X-ray Absorption Fine Structure (EXAFS), Secondary Ion Mass Spectrometry (SIMS), and Secondary Electron Microscopy/Energy Dispersive Analysis of X-rays (SEM/EDAX) have been developed to refine an existing model for the CCC formed on the AA2024-T3 surface, an Al-Cu aircraft alloy, by considering the composition and structure of the CCC formed on constituent intermetallic compounds (IMCs). The limited corrosion behavior of AA2024-T3 aluminum alloy is generally attributed to the presence of a variety of constituent IMC. These IMC particles are of the order of 1--20 mum which makes their direct analysis exceedingly difficult and has lead to a limited understanding of their surface chemical properties relative to CCC formation. To overcome this limitation, it was necessary to develop for the first time large area samples composed of compositionally homogenous thin films of the various IMCs found on the AA2024-T3 surface, which were galvanically attached to thin films of Al-4.2wt%Cu (representative of the AA2024-T3 matrix). This was performed in a two-step process: Disks of IMC compositions were formed by Reactive Arc Melting (RAM), followed by ultra-fast laser ablation of the RAM IMCs resulting in the formation of homogenous thin films

  13. Electrolytic treatment for magnesium alloys, alkaline type, full coat. (SAE standard)

    SciTech Connect

    1994-10-01

    This specification establishes the engineering requirements for anodic coatings, on magnesium and magnesium alloys, deposited from an alkaline electrolyte. This coating has been used typically to increase corrosion resistance, to provide surfaces which will ensure adhesion of organic coatings, and to impart abrasion resistance, but usage is not limited to such applications.

  14. Decreasing Bio-Degradation Rate of the Hydrothermal-Synthesizing Coated Mg Alloy via Pre-Solid-Solution Treatment

    PubMed Central

    Song, Dan; Li, Cheng; Zhang, Liwen; Ma, Xiaolong; Guo, Guanghui; Zhang, Fan; Jiang, Jinghua; Ma, Aibin

    2017-01-01

    In this study, we report an effective approach, pre-solid solution (SS) treatment, to reduce the in-vitro bio-degradation rate of the hydrothermal-synthesizing coated Mg–2Zn–Mn–Ca–Ce alloy in Hanks’ solution. Pre-SS treatment alters the microstructure of alloys, which benefits the corrosion resistances of the substrate itself and the formed coating as well. The micro-galvanic corrosion between the secondary phase (cathode) and the α-Mg phase (anode) is relieved due to the reduction of the secondary phase. Meanwhile, coating formed on the SS-treated alloy was compacter than that on as-cast alloy, which provides better protection against initial corrosion. PMID:28773223

  15. Treatment of a severe conversion disorder in a 10-year-old boy: a case study and overview.

    PubMed

    Ozsungur, Berna; Foto-Özdemir, Dilşad; Ozusta, Seniz; Topçu, Meral; Topaloğlu, Haluk

    2012-01-01

    Conversion disorder (CD) in children remains a major challenge both in pediatric and mental health clinics and is still a prevalent psychiatric disorder in developing countries. The authors describe a 10-year-old boy with the complaints of inability to walk, speak or eat, excessive drooling, urinary and fecal incontinence, disturbance from light and sound, and expression of needs only by eye movements. The patient diagnosed with CD was followed by the Department of Child and Adolescent Psychiatry with play therapy, individual psychotherapy and family therapy. At the end of three months, the patient was discharged. This is one of the most challenging cases of CD in children. The most important aim of the treatment is to understand the need for conversion symptoms and to constitute a healthy psychological environment for the child rather than to remove the physical symptoms.

  16. [Assessment and treatment of conversion disorder: the most fascinating borderline of psychiatry and neurology].

    PubMed

    Vataja, Risto; Leppävuori, Antero

    2012-01-01

    Conversion disorder or functional neurological disorder is a neurological symptom complex originating from psychological factors, which manifests in voluntary motor and sensory functions or as unexplained epilepsy-like seizures. Until the 1980's the disorder was called hysterical neurosis. Later on, various general terms, such as unexplained somatic symptoms, pseudoneurological, somatoformic, psychogenic, or psychosomatic symptoms, have been applied. The latest phrase, functional neurological symptoms, emphasizes the change in the functioning of the nervous system rather than in its structure.

  17. The enhancement of photo-thermo-electric conversion in tilted Bi2Sr2Co2O(y) thin films through coating a layer of single-wall carbon nanotubes light absorber.

    PubMed

    Wang, Shufang; Bai, Zilong; Yan, Guoying; Zhang, Hongrui; Wang, Jianglong; Yu, Wei; Fu, Guangsheng

    2013-07-29

    Light-induced transverse thermoelectric effect has been investigated in c-axis tilted Bi(2)Sr(2)Co(2)O(y) thin films coated with a single-wall carbon nanotubes light absorption layer. Open-circuit voltage signals were detected when the sample surface was irradiated by different lasers with wavelengths ranging from ultraviolet to near-infrared and the voltage sensitivity was enhanced as a result of the increased light absorption at the carbon nanotubes layer. Moreover, the enhancement degree was found to be dependent on the laser wavelength as well as the absorption coating size. This work opens up new strategy toward the practical applications of layered cobaltites in photo-thermo-electric conversion devices.

  18. Present and future of endovascular SFA treatment: stents, stent-grafts, drug coated balloons and drug coated stents.

    PubMed

    Bosiers, M; Deloose, K; Verbist, J; Peeters, P

    2008-04-01

    The current evolution towards treating more complex femoropopliteal lesions as seen in the renewed TASC II recommendations clearly reflects the continuous evolutions in femoropopliteal stent design. Recent stent design improvements focus on decreasing stent fractures rates which can negatively impact patency rates. By rearranging strut alignment towards helical connecting bridges or full helical stent designs, stent designers have successfully improved the fracture resistance of their stents. The superior fracture resistance of the latest stent generation in combination with the production of long nitinol stents of up to 20 cm in length allow that more difficult and complex lesions can be treated endovascularly. The continuous perfection of nitinol stent platforms followed by the transfer of coronary technologies (e.g. active coatings) towards peripheral devices might broaden the indications for the minimal invasive strategy towards TransAtlantic Inter-Society Consensus (TASC) II C&D lesions.

  19. Planar CH3NH3PbBr3 hybrid solar cells with 10.4% power conversion efficiency, fabricated by controlled crystallization in the spin-coating process.

    PubMed

    Heo, Jin Hyuck; Song, Dae Ho; Im, Sang Hyuk

    2014-12-23

    A power conversion efficiency of 10.4% is demonstrated in planar CH3 NH3 PbBr3 hybrid solar cells without hysteresis of the J-V curve, by way of controlled crystallization in the spin-coating process. The high efficiency is attributed to the formation of a dense CH3 NH3 PbBr3 thin film by the introduction of HBr solution because the HBr increases the solubility of the CH3 NH3 PbBr3 and forms a thinner CH3 NH3 PbBr3 layer with full surface coverage.

  20. Impact of Sn/F Pre-Treatments on the Durability of Protective Coatings against Dentine Erosion/Abrasion

    PubMed Central

    Ganss, Carolina; Lussi, Adrian; Peutzfeldt, Anne; Naguib Attia, Nader; Schlueter, Nadine

    2015-01-01

    For preventing erosive wear in dentine, coating with adhesives has been suggested as an alternative to fluoridation. However, clinical studies have revealed limited efficacy. As there is first evidence that Sn2+ increases bond strength of the adhesive Clearfil SE (Kuraray), the aim of the present study was to investigate whether pre-treatment with different Sn2+/F− solutions improves the durability of Clearfil SE coatings. Dentine samples (eight groups, n=16/group) were freed of smear layer (0.5% citric acid, 10 s), treated (15 s) either with no solution (control), aminefluoride (AmF, 500 ppm F−, pH 4.5), SnCl2 (800/1600 ppm Sn2+; pH 1.5), SnCl2/AmF (500 ppm F−, 800 ppm Sn2+, pH 1.5/3.0/4.5), or Elmex Erosion Protection Rinse (EP, 500 ppm F−, 800 ppm Sn2+, pH 4.5; GABA International), then rinsed with water (15 s) and individually covered with Clearfil SE. Subsequently the specimens were subjected to an erosion/abrasion protocol consisting of 1320 cycles of immersion in 0.5% citric acid (5°C/55°C; 2 min) and automated brushing (15 s, 200 g, NaF-toothpaste, RDA 80). As the coatings proved stable up to 1320 cycles, 60 modified cycles (brushing time 30 min/cycle) were added. Wear was measured profilometrically. After SnCl2/AmF, pH 4.5 or EP pre-treatment all except one coating survived. In the other groups, almost all coatings were lost and there was no significant difference to the control group. Pre-treatment with a Sn2+/F− solution at pH 4.5 seems able to improve the durability of adhesive coatings, rendering these an attractive option in preventing erosive wear in dentine. PMID:26075906

  1. A Novel Single-Step Surface-Treatment Process for Forming Cr-Nitride Coatings on Steels

    NASA Astrophysics Data System (ADS)

    Lu, X. J.; Xiang, Z. D.

    2017-02-01

    A novel single-step surface-treatment process is demonstrated for forming Cr-nitride coatings on steels. The process was carried out at 1327 K (1100 °C) for two steel grades with differing carbon concentrations. For steel grade with 0.42 to 0.5C (wt pct), the coatings formed consisted of an outer Cr2N layer and an inner Cr-carbide layer with a Cr-enriched interdiffusion zone underneath. However, for steel grade with C ≤ 0.17 wt pct, the inner Cr-carbide layer was absent.

  2. Characterization of microstructure and surface properties of hybrid coatings of WC-CoCr prepared by laser heat treatment and high velocity oxygen fuel spraying

    SciTech Connect

    Zhang Shihong Cho, Tong-Yul; Yoon, Jae-Hong; Fang, Wei; Song, Ki-O; Li Mingxi; Joo, Yun-Kon; Lee, Chan Gyu

    2008-10-15

    The microstructure and microhardness of high velocity oxygen fuel-sprayed WC-CoCr coatings were comparatively studied both before and after laser heat treatment of the coatings. Optical microscopy, scanning electron microscopy, X-ray diffraction and microhardness testing were applied to investigate the microstructure, phase composition, porosity and microhardness. The results indicate that WC is still present, and W{sub 2}C has appeared, while neither cobalt nor {sigma}-CrCo is detectable. Co{sub 4}W{sub 2}C has appeared in the high velocity oxygen fuel-sprayed coating after laser heat treatment as compared to the coating before laser treatment. The relative content of the W{sub 2}C has not increased with laser treatment, but the laser treatment has essentially eliminated the porosity almost entirely, providing a more homogeneous and densified microstructure. The laser heat treatment has effected the formation of a denser compact coating on the substrate. After laser heat treatment, the thickness of the coating has decreased from 300 {mu}m to 225 {mu}m. This corresponds to an average porosity in the high velocity oxygen fuel-sprayed coating that is approximately five times greater than that in the subsequently laser heat-treated coating. The laser treatment has also resulted in an increased hardness of the coating near the surface, where the average value increased from Hv{sub 0.2} = 1262.4 in the coating before laser heat treatment to Hv{sub 0.2} = 1818.7 after laser heat treatment.

  3. Effect of Sealing Treatment on Corrosion Resistance of Plasma-Sprayed NiCrAl/Cr2O3-8 wt.%TiO2 Coating

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Wang, Zehua; Lin, Pinghua; Lu, Wenhuan; Zhou, Zehua; Jiang, Shaoqun

    2011-03-01

    Plasma-sprayed ceramic coatings inherently contain pores and micro-cracks which is deleterious when performed in aggressive environment. Various methods were applied to the as-sprayed coatings in order to improve the corrosion resistance. In the investigation of this study, plasma-sprayed NiCrAl/Cr2O3-8 wt.%TiO2 coatings were sealed by epoxy resin and silicone resin, respectively. Coatings were characterized by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), optical microscopy (OM) and x-ray diffraction (XRD). The possible corrosion mechanism was discussed. The results of salt spray test and electrochemical measurements indicated that after the sealing treatment, the porosity of coatings decreased obviously and a compact layer was formed to protect the coating from corrosion. The silicone resin proved to be more effective than epoxy resin in enhancing the corrosion resistance of the coatings used in this research.

  4. Immobilization of pectinase and lipase on macroporous resin coated with chitosan for treatment of whitewater from papermaking.

    PubMed

    Liu, Kai; Zhao, Guanglei; He, Beihai; Chen, Lihui; Huang, Liulian

    2012-11-01

    Anionic residues and pitch deposits in whitewater negatively impact the operation of paper-forming equipment. In order to remove these substances, a macroporous resin based on a methyl acrylate matrix was synthesized and coated with chitosan of various molecular weights through glutaraldehyde cross-linking. Pectinase from Bacillus licheniformis and lipase from Thermomyces lanuginosus were immobilized on the resin coated with chitosan by a Schiff base reaction. The highest hydrolysis activities of the immobilized enzymes were achieved by using chitosan with 10×10(5)DaMW for coating and 0.0025% glutaraldehyde for cross-linking chitosan. The cationic demand and pitch deposits in whitewater were reduced by 58% and 74%, respectively, when treating whitewater with immobilized dual-enzymes for 15min at 55°C and pH 7.5. This method is useful for treatment of whitewater in the papermaking industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Surface properties and water treatment capacity of surface engineered silica coated with 3-(2-aminoethyl) aminopropyltrimethoxysilane

    NASA Astrophysics Data System (ADS)

    Majewski, Peter; Keegan, Alexandra

    2012-01-01

    This study's focus was on the water-based, one-pot preparation and characterisation of silica particles coated with 3-(2-aminoethyl)aminopropyltrimethoxysilane (Diamo) and the efficiency of the material in removing the pathogens Escherichia coli, Pseudomonas aeruginosa, Mycobacterium immunogenum, Vibrio cholerae, poliovirus, and Cryptosporidium parvum. The water-based processing resulted in Diamo coated silica particles with significantly increased positive surface charge as determined by zeta potential measurements. In addition, X-ray photoelectron spectrometry of pure and Diamo coated silica confirmed the presence of Diamo on the surface of the particles. Thermogravimetric measurements and chemical analysis of the silica indicated a surface concentration of amine groups of about 1 mmol/gsilica. Water treatment tests with the pathogens showed that a dose of about 10 g appeared to be sufficient to remove pathogens from pure water samples which were spiked with pathogen concentrations between about 102 and 104 cfu/mL.

  6. The adhesion performance of epoxy coating on AA6063 treated in Ti/Zr/V based solution

    NASA Astrophysics Data System (ADS)

    Zhu, Wen; Li, Wenfang; Mu, Songlin; Yang, Yunyu; Zuo, Xi

    2016-10-01

    An environment-friendly titanium/zirconium/vanadium-based (Ti/Zr/V) conversion coating was prepared on aluminum alloy 6063 (AA6063). The epoxy powder coatings were applied on the AA6063 samples with/without Ti/Zr/V conversion coatings via electrostatic spraying. The morphology and composition of the conversion coating were studied by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The surface free energy components of AA6063 samples were measured by a static contact angle measuring device with Owens method. The adhesion properties of the epoxy coating on AA6063 treated with different conversion times were evaluated using a pull-off tester. The Ti/Zr/V conversion coating was mainly composed of metal oxide (TiO2, ZrO2, V2O5, Al2O3, etc.), metal fluoride (ZrF4, AlF3, etc.) and metal organic complex. The formation time of this conversion coating was reduced to 50 s. After such surface treatment, the samples' surface roughness was increased and the contact angle with water was decreased. Both the surface free energy and the work of adhesion were increased. The adhesion strength between the epoxy coating and AA6063 was enhanced significantly.

  7. Sputum smear conversion and treatment outcomes for tuberculosis patients with and without diabetes in Fiji.

    PubMed

    Prasad, P; Gounder, S; Varman, S; Viney, K

    2014-09-21

    Contexte : Trois centres de traitement de la tuberculose (TB) dans le cadre du Programme national de Lutte contre la TB aux Fidji.Objectif : Déterminer la prévalence du diabète (DM) parmi les patients tuberculeux entre 2010 et 2012 et d'évaluer la conversion des frottis de crachats et les résultats du traitement de la TB en comparant les patients avec et sans DM.Schéma : Etude rétrospective descriptive basée sur les données recueillies en routine à partir des registres de la TB et des dossiers des patients hospitalisés.Résultats : De 577 patients tuberculeux identifiés, des informations relatives au DM étaient disponibles pour 567 d'entre eux (98%) ; parmi ceuxci, 68 (12%) étaient diabétiques. Le résultat du frottis à 2 mois était disponible pour 254 (82%) patients atteints de TB pulmonaire à frottis positif. Le taux de conversion du frottis (de positif à négatif) était identique chez tous les patients tuberculeux avec ou sans DM (78% contre 80% ; P = 0,66). Le résultat du traitement anti-tuberculeux était disponible pour 462 patients ; il n'y avait pas non plus de différence significative en termes de succès du traitement (91% chez les patients avec DM contre 84% chez les patients sans DM ; P = 0,06).Conclusion : Le DM est fréquent chez les patients tuberculeux aux Fidji. Le taux de conversion du frottis ne s'est cependant pas avéré différent chez les patients avec et sans DM, et il n'y a pas non plus eu de différence significative en termes de succès du traitement entre les deux groupes.

  8. Antifogging and antireflection coatings fabricated by integrating solid and mesoporous silica nanoparticles without any post-treatments.

    PubMed

    Xu, Ligang; He, Junhui

    2012-06-27

    Antifogging and -reflection coatings were fabricated on glass and poly(methyl methacrylate) (PMMA) substrates by integrating solid silica nanoparticles of 25 nm (S-25) and mesoporous silica nanoparticles (MSNs) of 45 nm via layer-by-layer assembly without any post-treatments. Superhydrophilicity and a maximum transmittance of 98.5% in the visible spectral range was achieved for the (PDDA/S-25)4/(PDDA/MSNs) coating deposited on slide glass. The maximum transmittance even reached as high as 99.3% in the visible spectral range by applying a coating of (PDDA/S-25)8/(PDDA/MSNs) on PMMA substrate. Scanning and transmission electron microscopy were used to observe the morphology and structure of nanoparticles and coating surfaces. Optical properties were characterized by UV-visible spectrophotometer. Surface wettability was studied by a contact angle/interface system. The influence of mesopores was also discussed on the transmission and wetting properties of coatings. The high porosity of mesoporous nanoparticles and loose stacking of solid and mesoporous nanoparticles are considered to significantly contribute to the enhancements of both light transmission and hydrophilicity.

  9. Improving interfacial, mechanical and tribological properties of alumina coatings on Al alloy by plasma arc heat-treatment of substrate

    NASA Astrophysics Data System (ADS)

    Hou, Guoliang; An, Yulong; Zhao, Xiaoqin; Zhou, Huidi; Chen, Jianmin; Li, Shuangjian; Liu, Xia; Deng, Wen

    2017-07-01

    Plasma sprayed ceramic coatings can be used to improve the mechanical properties and wear resistance of aluminum alloys, but there are still some challenges to effectively increase their interfacial adhesion. Thus we conducted plasma arc-heat treatment (PA-HT) of Al alloy substrate before plasma spraying, hoping to tune the microstructure of Al2O3 coatings and improve their interfacial strength as well as mechanical and tribological properties. The influences of PA-HT on the microstructure of alumina coatings were analyzed by X-ray diffraction, transmission electron microscopy and scanning electron microscopy, while its effect on mechanical and tribological properties were evaluated by a nano-indentation tester and a friction and wear tester. Results demonstrate that a few columnar δ-Al2O3 generated on substrate surface after PA-HT at 200-250 °C can induce the epitaxial growth of γ-Al2O3 grains in Al2O3 coatings, thereby enhancing their interfacial bonding. Besides, elevating substrate temperature can help alumina droplets to melt into the interior of substrate and eliminate holes at the interface, finally increasing the interfacial anchorage force. More importantly, no interfacial holes can allow the heat of droplets to be rapidly transmitted to substrate, which is beneficial to yield smaller crystals in coatings and greatly enhance their strength, hardness and wear resistance.

  10. Comparison of bacteriological conversion and treatment outcomes among MDR-TB patients with and without diabetes in Mexico: Preliminary data.

    PubMed

    Muñoz-Torrico, M; Caminero Luna, J; Migliori, G B; D'Ambrosio, L; Carrillo-Alduenda, J L; Villareal-Velarde, H; Torres-Cruz, A; Flores-Ergara, H; Martínez-Mendoza, D; García-Sancho, C; Centis, R; Salazar-Lezama, M Á; Pérez-Padilla, R

    Diabetes mellitus (DM) is a well-known risk factor for tuberculosis (TB). However, it is not known to what extent DM affects the outcome in patients with multidrug-resistant (MDR-TB) and extensively drug-resistant TB (XDR-TB) treated with second-line anti-TB drugs. The objective of this study was to compare the microbiological evolution (sputum smear and culture conversion) and final outcomes of MDR/XDR-TB patients with and without DM, managed at the national TB reference centre in Mexico City. Ninety patients were enrolled between 2010 and 2015: 73 with MDR-TB (81.1%), 11 with pre-XDR-TB (e.g. MDR-TB with additional resistance to one injectable drug or a fluoroquinolone, 12.2%) and 6 (6.7%) with XDR-TB. Out of these, 49 (54.4%) had DM and 42 (86%) were undergoing insulin treatment. No statistically significant differences were found in treatment outcomes comparing DM vs. non-DM MDR-TB cases: 18/32 (56.3%) of DM cases and 19/24 (79.2%) non DM patients achieved treatment success (p=0.07). The time to sputum smear and culture conversion was longer (although not statistically) in patients without DM, as follows: the mean (±SD) time to sputum smear conversion was 53.9 (±31.4) days in DM patients and 65.2 (±34.8) days in non-DM ones (p=0.15), while the time to culture conversion was 66.2 (±27.6) days for DM and 81.4 (±37.7) days for non-DM MDR-TB cases (p=0.06). The study results support the Mexican National TB programme to strengthen its collaboration with the DM programme, as an entry point for TB (and latent TB infection) screening and management. Copyright © 2016 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

  11. Impacting Care and Treatment of the Burn Patient Conversion to Electronic Documentation.

    PubMed

    Hampe, Holly M; Keeling, Terri; Fontana, Michelle; Balcik, Debbie

    Improving patient care through enhanced electronic communication among health care providers is aimed at reducing the number of medication and medical errors. The American Reinvestment and Recovery Act (ARRA) was signed into law in 2009, supporting the federal government's commitment to the improvement of health care quality, safety, and efficiency through requirements to implement an electronic health record by October 2015 or hospitals and eligible providers potentially realizing penalties or reduced reimbursement rates. In addition to ARRA, Congress presented another initiative to further advance the delivery of high-quality health care, the Health Information Technology for Economic and Clinical Health Act (HITECH), leading to the authorization of $27 billion to encourage health care providers to achieve meaningful use of the electronic health record. However, the conversion of the paper medical records to an electronic version has been challenging, particularly in specialty departments. The burn unit of a tertiary hospital located in the Pittsburgh area experienced such challenges. A project plan, developed in 2009 prior to the electronic medical record going live, involved a multidisciplinary team, consisting of providers, nurses, and information system builders who came together to determine how to capture the totality of the burn unit documentation. The goal of the project was to develop an electronic documentation tool and provide a system to accurately and efficiently evaluate documentation compliance with the staff. The Lund Browder documentation tool, used with the paper medical record, was the selected tool for the electronic conversion. This tool has been regarded by most health care organizations as being the most accurate in measuring the extent and degree of the burn. With the paper documentation tool, the staff was, on average, 74% compliant with the Lund Browder tool. The electronic version and availability of the tool increased compliance to 100

  12. Internal porosity of mineral coating supports microbial activity in rapid sand filters for groundwater treatment.

    PubMed

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin; Mateiu, Ramona V; Albrechtsen, Hans-Jørgen; Smets, Barth F

    2014-11-01

    A mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. The coating changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity, and abundance of microbiota. This study reveals that a mineral coating can positively affect the colonization and activity of microbial communities in rapid sand filters. To understand this effect, we investigated the abundance, spatial distribution, colonization, and diversity of all and of nitrifying prokaryotes in filter material with various degrees of mineral coating. We also examined the physical and chemical characteristics of the mineral coating. The amount of mineral coating correlated positively with the internal porosity, the packed bulk density, and the biologically available surface area of the filter material. The volumetric NH4 (+) removal rate also increased with the degree of mineral coating. Consistently, bacterial 16S rRNA and amoA abundances positively correlated with increased mineral coating levels. Microbial colonization could be visualized mainly within the outer periphery (60.6 ± 35.6 μm) of the mineral coating, which had a thickness of up to 600 ± 51 μm. Environmental scanning electron microscopic (E-SEM) observations suggested an extracellular polymeric substance-rich matrix and submicron-sized bacterial cells. Nitrifier diversity profiles were similar irrespective of the degree of mineral coating, as indicated by pyrosequencing analysis. Overall, our results demonstrate that mineral coating positively affects microbial colonization and activity in rapid sand filters, most likely due to increased volumetric cell abundances facilitated by the large surface area of internal mineral porosity accessible for microbial colonization.

  13. Internal Porosity of Mineral Coating Supports Microbial Activity in Rapid Sand Filters for Groundwater Treatment

    PubMed Central

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin; Mateiu, Ramona V.; Albrechtsen, Hans-Jørgen

    2014-01-01

    A mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. The coating changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity, and abundance of microbiota. This study reveals that a mineral coating can positively affect the colonization and activity of microbial communities in rapid sand filters. To understand this effect, we investigated the abundance, spatial distribution, colonization, and diversity of all and of nitrifying prokaryotes in filter material with various degrees of mineral coating. We also examined the physical and chemical characteristics of the mineral coating. The amount of mineral coating correlated positively with the internal porosity, the packed bulk density, and the biologically available surface area of the filter material. The volumetric NH4+ removal rate also increased with the degree of mineral coating. Consistently, bacterial 16S rRNA and amoA abundances positively correlated with increased mineral coating levels. Microbial colonization could be visualized mainly within the outer periphery (60.6 ± 35.6 μm) of the mineral coating, which had a thickness of up to 600 ± 51 μm. Environmental scanning electron microscopic (E-SEM) observations suggested an extracellular polymeric substance-rich matrix and submicron-sized bacterial cells. Nitrifier diversity profiles were similar irrespective of the degree of mineral coating, as indicated by pyrosequencing analysis. Overall, our results demonstrate that mineral coating positively affects microbial colonization and activity in rapid sand filters, most likely due to increased volumetric cell abundances facilitated by the large surface area of internal mineral porosity accessible for microbial colonization. PMID:25192987

  14. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer.

    PubMed

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-09-08

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse "L" curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was "S" curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies.

  15. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer

    NASA Astrophysics Data System (ADS)

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-09-01

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse “L” curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was “S” curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies.

  16. Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer

    PubMed Central

    Zhou, Zijun; Du, Changwen; Li, Ting; Shen, Yazhen; Zhou, Jianmin

    2015-01-01

    Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse “L” curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was “S” curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies. PMID:26348791

  17. Conversion of municipal solid waste into carboxylic acids by anaerobic countercurrent fermentation: effect of using intermediate lime treatment.

    PubMed

    Aiello-Mazzarri, Cateryna; Coward-Kelly, Guillermo; Agbogbo, Frank K; Holtzapple, Mark T

    2005-11-01

    Municipal solid waste (MSW) and sewage sludge (SS) were combined and anaerobically converted into carboxylate salts by using a mixed culture of acid-forming microorganisms. MSW is an energy source and SS is a source of nutrients. In this study, MSW and SS were combined, so they complemented each other. Four fermentors were arranged in series for a countercurrent fermentation process. In this process, the solids and liquid were transferred in opposite directions, with the addition of fresh biomass to fermentor 1 and fresh liquid media to fermentor 4. An intermediate lime treatment of solids exiting fermentor 3 before entering fermentor 4 was applied to improve the product acid concentration from the untreated MSW/SS fermentations. All fermentations were performed under anaerobic conditions at 40 degrees C. Calcium carbonate was added to neutralize the carboxylic acids and to control the pH. Iodoform was used as a methanogen inhibitor. Carboxylic acid concentration and gas composition were determined by gas chromatography. Substrate conversion was measured by volatile solids loss, and carboxylic acid productivity was calculated as the function of the total carboxylic acids produced, the amount of liquid in all fermentors, and time. The addition of intermediate lime treatment increased product concentration and conversion by approx 30 and 15%, respectively. The highest carboxylic acid concentrations for untreated MSW/SS fermentations with and without intermediate lime treatment were 22.2 and 17.7 g of carboxylic acid/L of liquid, respectively. These results confirm that adding a treatment step between fermentor 3 and fermentor 4 will increase the digestibility and acid productivity of the fermentation.

  18. Biological response of Sr-containing coating with various surface treatments on titanium substrate for medical applications

    NASA Astrophysics Data System (ADS)

    Yang, Shih-Ping; Lee, Tzer-Min; Lui, Truan-Sheng

    2015-08-01

    An implant requires a suitable surface to trigger osteointegration. The surface characteristics and chemical composition are important factors in this process. Plasma spraying and micro-arc oxidation can be used to fabricate rough and porous structures for medical applications. Strontium (Sr) has been shown to prevent osteoporosis in vitro and in vivo. However, few scientists have evaluated the biological response of Sr-containing coatings on different surface treatments. In this study, a sand-blasted (SB) surface (as the control), plasma-sprayed hydroxyapatite (HA) and Sr-substituted HA coatings (HAPS and SrHAPS, respectively), calcium phosphate and Sr-containing calcium phosphate micro-arc oxidation surface (CPM and SrCPM, respectively) were analyzed in terms of human osteoblastic cell (MG63) response. Sr was confirmed to be incorporated into the surface. SrHAPS and SrCPM specimens had higher cell responses than those of the HAPS and CPM groups, respectively. The cells cultured on SrCPM and SrHAPS specimens exhibited high proliferation and differentiation. However, CPM and SrCPM specimens stimulated more ECM-like structures than other specimens. The results show that Sr-containing coatings have good characteristics that enhance cell response. The SrCPM coating is a suitable implant surface treatment for clinical applications.

  19. Drug loaded silica coated MnFe2O4 ferromagnetic biomaterials for targeted cancer treatment

    NASA Astrophysics Data System (ADS)

    Anand, Vikas; Singh, K. J.; Kaur, Kulwinder; Bhatia, Gaurav

    2017-05-01

    Magnetically attracted silica coated MnFe2O4 samples have been prepared by using co-precipitation method. Structural changes have been confirmed from XRD spectra. Ferromagnetic behavior of samples has been studied by using vibration sample magnetometer. Cytotoxicity and cell culture of samples have been investigated by using human MG63 cell line and found that sample provide a healthy environment to the growth of cell lines. Drug carrier ability of sample has been checked with gentamycin as an antibiotic and results show that sample can be used as excellent drug carriers. Drug loaded samples can be easily targeted to specific area due to their attractive nature towards external magnetic field. Moreover, magnetic nanoparticles can also be used to kill the cancer cells by using hyperthermia technique. Hyperthermia is a process to raise the temperature of surrounding cells in the presence of external AC magnetic field above the maximum temperature limit for surviving of the cancer cells. Cancer cell can survive only up to 47°C. After that cancer cells start to die, but healthy cells can easily survive up to higher temperature. Our results indicate that prepared samples possess good drug carrier ability and hence, can be potential candidates for cancer cell treatment.

  20. TiO2 and polyvinyl alcohol (PVA) coated polyester filter in bioreactor for wastewater treatment.

    PubMed

    Liu, Lifen; Zhao, Chuanqi; Yang, Fenglin

    2012-04-15

    Prepared by coating TiO(2)/polyvinyl alcohol (PVA) on a low cost polyester filter cloth (22 μm), a composite membrane (10 μm pore size) was successfully used in an anoxic/oxic membrane bioreactor (A/O-MBR) for treating a simulate wastewater in removing nitrate/ammonium for water reuse in a polyester fiber production plant. Its permeate flux and the anti-fouling properties against extracellular polymeric substances (EPS) were studied. Comparing with a commercial (0.1 μm) PVDF (polyvinylidene fluoride) membrane, similar effluent qualities were achieved, meeting the basic COD requirements for reuse. Anti-EPS accumulation, the TiO(2)/PVA Polyester composite membrane had higher sustained permeability and required less frequent cleaning. Its filtration time was 4 times longer when operated at a higher flux than the PVDF membrane. The nano-TiO(2) enhances the interaction between PVA and polyester, forms a more hydrophilic surface, drastically reduces the contact angle with water and reduces EPS fouling. The slow (trans-membrane pressure) TMP rise, loose cake layer, the low filtration resistances, and the EPS, SEM analysis confirmed the advantage of the composite membrane. Potential in lowering the membrane cost, the operation and maintenance cost, and in enhancing MBR waste water treatment efficiency is expected by the use of this new composite membrane.

  1. Impacts of tilling and covering treatments on the biosolids solar drying conversion from class B to class A.

    PubMed

    Song, Inhong; O'Shaughnessy, Susan A; Choi, Christopher Y; Gerba, Charles P

    2014-01-01

    The objective of this study was to evaluate the effects of tillage and cover treatments of solar drying on the conversion of class B treated sewage sludge to a class A product. The experiments were performed over two years at Green Valley, Arizona in steel-constructed sand-filled drying beds of 1.0 m (width) x 3.0 m (length) x 0.6 m (depth). Freshly produced aerobically and anaerobically digested biosolids from nearby wastewater treatment plants received tillage and cover treatments for expediting solar drying and microbial inactivation. During the summer drying, covered drying bed increased faecal inactivation rate by 26% over other treatments and automated rain shield abated faecal coliform regrowth from summer rains. Tilling accelerated evaporation of moisture from the biosolids and increased the inactivation rate of faecal coliforms during the summer season. An automated retractable roof to protect the biosolids from rain aided in maintaining class A criteria by preventing dried biosolids from re-wetting by rainfall. However, results from tilling and passive solar heating during the cold winter seasons did not improve the faecal coliform inactivation rate due mainly to lower ambient temperatures. Thus, tilling and cover treatments can be effective in accelerating biosolids solar drying and thus enhancing pathogen inactivation during the summer season. Investigation on the effects of tillage depth and frequency is recommended to determine optimal tilling practice.

  2. Effect of silica coating and silane surface treatment on the bond strength of soft denture liner to denture base material.

    PubMed

    Atsü, Saadet; Keskın, Yasemin

    2013-01-01

    This study investigated the effects of different surface treatments on the tensile bond strength of an autopolymerizing silicone denture liner to a denture base material after thermocycling. Fifty rectangular heat-polymerized acrylic resin (QC-20) specimens consisting of a set of 2 acrylic blocks were used in the tensile test. Specimens were divided into 5 test groups (n=10) according to the bonding surface treatment as follows: Group A, adhesive treatment (Ufi Gel P adhesive) (control); Group S, sandblasting using 50-µm Al2O3; Group SCSIL, silica coating using 30-µm Al2O3 modified by silica and silanized with silane agent (CoJet System); Group SCA, silica coating and adhesive application; Group SCSILA, silica coating, silane and adhesive treatment. The 2 PMMA blocks were placed into molds and the soft lining materials (Ufi Gel P) were packed into the space and polymerized. All specimens were thermocycled (5,000 cycles) before the tensile test. Bond strength data were analyzed using 1-way ANOVA and Duncan tests. Fracture surfaces were observed by scanning electron microscopy. X-ray photoelectron spectrometer (XPS) and Fourier Transform Infrared spectrometer (FTIR) analysis were used for the chemical analysis and a profilometer was used for the roughness of the sample surfaces. The highest bond strength test value was observed for Group A (1.35±0.13); the lowest value was for Group S (0.28±0.07) and Group SCSIL (0.34±0.03). Mixed and cohesive type failures were seen in Group A, SCA and SCSILA. Group S and SCSIL showed the least silicone integrations and the roughest surfaces. Sandblasting, silica coating and silane surface treatments of the denture base resin did not increase the bond strength of the silicone based soft liner. However, in this study, the chemical analysis and surface profilometer provided interesting insights about the bonding mechanism between the denture base resin and silicone soft liner.

  3. Enteric-coated cysteamine for the treatment of paediatric non-alcoholic fatty liver disease.

    PubMed

    Dohil, R; Schmeltzer, S; Cabrera, B L; Wang, T; Durelle, J; Duke, K B; Schwimmer, J B; Lavine, J E

    2011-05-01

    Non-alcoholic fatty liver disease (NAFLD) is a common cause of liver disease in children. Hepatic fat accumulation and oxidative stress contribute to its pathogenesis. Cysteamine bitartrate readily traverses cellular membranes and is a potent antioxidant. To evaluate the safety and efficacy of enteric-coated (EC) cysteamine in children with NAFLD. Children, aged ≥10 y, meeting screening criteria with biopsy-proven NAFLD and serum ALT ≥60 IU/L, received twice-daily EC-cysteamine for 24 weeks. Monthly ALT, AST, body mass index (BMI) and gastrointestinal symptom scores were measured. Subjects with >50% reduction or normalisation of ALT achieved the primary endpoint. Of the 13 children enrolled (mean age 14.0 years), 11 completed EC-cysteamine therapy (mean dose 15.2 mg/kg/day) and were included in the final analysis. For these 11 subjects, the mean ALT levels at baseline and 24 weeks were 120.2 and 55 IU/L respectively (P = 0.002), and the AST levels were 60 and 36 IU/L respectively (P = 0.007). The primary endpoint was reached in 7 and normalisation (≤40 IU/L) of ALT in 5. After 24 week therapy, mean adiponectin levels increased (P = 0.009) and CK-18 fragment levels decreased (P = 0.013), insulin levels remained unchanged (P = 0.99). Mean leptin levels were decreased in responders (P = 0.044). Mean BMI was 34.5 at baseline and 34.2 kg/m(2) after treatment (P = 0.35). Mean symptom scores at baseline (1.1) and at 24 weeks (0.7) were similar. No major adverse events were reported. Enteric-coated cysteamine reduces ALT and AST levels in children with NAFLD without reduction in body mass index. Further studies will evaluate optimal cysteamine therapeutic dose and effect on liver histology in NAFLD (Clinicaltrials.gov protocol ID: 07-1699). © 2011 Blackwell Publishing Ltd.

  4. An in vitro evaluation of the zirconia surface treatment by mesoporous zirconia coating on its bonding to resin cement.

    PubMed

    Zhang, Yanli; Sun, Ting; Liu, Ruoyu; Feng, Xiaoli; Chen, Aijie; Shao, Longquan

    2014-01-01

    The effect of zirconia surface treatment by mesoporous zirconia coating on the microtensile bond strength (MTBS) between zirconia and resin cement was investigated in this work. 160 zirconia specimens were prepared and divided into four groups according to surface treatments: (1) airborne-particle-abrasion treatment (APA); (2) glass infiltration and hydrofluoric acid treatment (GI+HF); (3) mesoporous zirconia coating (MZ); and (4) no treatment (C). The as-prepared zirconia specimens were bonded using Panavia F2.0 and RelyX Unicem. The MTBS values were tested using a universal testing machine, and data were analyzed using ANOVA and SNK methods (a=0.05). The MTBS values obtained after GI+HF and MZ treatments were significantly higher than those obtained after APA and C treatments (P<0.05), especially for samples cemented with Panavia F2.0. The results reveal that zirconia surface treatments using GI+HF and MZ yield higher bond strength than those using APA or C, regardless of the resin cements.

  5. The formation of FHA coating on biodegradable Mg-Zn-Zr alloy using a two-step chemical treatment method

    NASA Astrophysics Data System (ADS)

    Jiang, S. T.; Zhang, J.; Shun, S. Z.; Chen, M. F.

    2016-12-01

    To improve the corrosion resistance of the biomedical magnesium alloy, a two-step chemical treatment method has been employed to prepare an FHA coating on the alloy surface. Prior to forming an FHA layer, the samples of Mg-3 wt% Zn-0.5 wt% Zr alloy were soaked in HF with concentration of 20% (v/v) at 37 °C temperature for 2 h, and were then placed into an aqueous solution with 0.1 mol/L Ca(NO3).4H2O and 0.06 mol/L NH4H2PO4 at 90 °C to prepare the Ca-P coating. The concentrations of Mg2+, F- ions, and pH variation with immersing time in the solution were investigated to explore the growth mechanism of FHA. The surface morphologies and compositions of the coatings were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. The results showed that the alloy surface treated with acid formed a layer of MgF2 nanoparticles with a thickness of 0.7 μm. The corrosion resistance of coatings in SBF solution was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results showed that the substrate with FHA coating had good corrosion resistance. After immersing into the calcium phosphate solution, some small spherical particles were first formed on the surface; these then cover the surface completely after 20 min. Some clusters consisting of needle-like crystal were observed in the spherical particles covering the surface, and the Ca/P ratio of the needle-like crystal was 1.46, clearly growing along the c axis preferred orientation growth. After immersion for 60 min, the FHA coating with completely uniform growth was obtained on the Mg-Zn-Zr alloy surface with its thickness reaching about 120 μm.

  6. Synthesis of dittmarite/Mg(OH)2 composite coating on AZ31 using hydrothermal treatment

    NASA Astrophysics Data System (ADS)

    Zhao, Qing; Mahmood, Waqas; Zhu, Yanying

    2016-03-01

    In this work, we have used hydrothermal method for the synthesis of dittmarite/Mg(OH)2 composite (DMC) layer on AZ31 alloy of magnesium. The synthesized coating was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). In a test immersion into the Hank's mixture for 31 days, the synthesized coating inhibited corrosion of AZ31 significantly and the amorphous calcium apatite precursor deposited on the coating surface. In another tape test, we noticed strong adhesion between the coating and substrate that eventually concludes that the synthesized coating is hydrophilic and a promising candidate to be used in the absorbable implant materials. Besides, the cytotoxicity of the AZ31 alloy with DMC coating, grown under different conditions on L-929 cells in vitro was examined indirectly through the growth inhibition method (MTT assay). The cytotoxicity of the deposited coating lie between 0 ∼ 1 that indicates it as a promising biomaterial.

  7. Optimization of sugarcane bagasse conversion by hydrothermal treatment for the recovery of xylose.

    PubMed

    Boussarsar, Houda; Rogé, Barbara; Mathlouthi, Mohamed

    2009-12-01

    This work aims at the valorization of sugarcane bagasse by extracting xylose which is destined to the production of xylitol after purification and hydrogenation. Our approach consists in applying the principle of biorefinery to sugarcane bagasse because of its hemicellulose composition (particularly rich in xylan: (92%)). Optimizing of the thermal treatment was investigated. A treatment at 170 degrees C for 2 h was found optimal, with higher solubilzation of hemicellulose than that at 150 degrees C and lower degradation of sugar monomers than 190 degrees C. Recovery of xylose was high and the purity of xylose solution (78%) allows expecting an easy purification and separation of xylose before hydrogenation. Analysis of thermal hydrolyzates shows the presence of xylan oligomers and polymers with large distribution of DPs. This fraction should be submitted to enzymatic treatment to recover more xylose monomer.

  8. Advanced Multifunctional Coating

    DTIC Science & Technology

    2011-08-17

    and UV durability of then current chrome free TT-P-2756 SPTC • Leverage APC technology into SPTC • Coating uses same fluoropolyurethane technology...as APC currently used on C-17 • Leverage recent advances in chrome free corrosion inhibitor technology • State of the art chrome free corrosion...coat exposed metal Aluminum Base Metal Original Finish System Aged APC Topcoat Conversion Coat Chromic Acid Anodize Aluminum Cladding Original Primer

  9. Combined effects of sodium chlorite dip treatment and chitosan coatings on the quality of fresh-cut d’Anjou pears

    USDA-ARS?s Scientific Manuscript database

    This study evaluated the effects of sodium chlorite (SC) alone and its sequential treatment with edible coatings on browning inhibition and quality maintenance of fresh-cut d’Anjou pears. Edible coatings were prepared from chitosan (CH) and its water soluble derivative: carboxymethyl chitosan (CMCH...

  10. Femtosecond laser treatment for the design of electro-insulating superhydrophobic coatings with enhanced wear resistance on glass.

    PubMed

    Boinovich, Ludmila B; Domantovskiy, Alexandre G; Emelyanenko, Alexandre M; Pashinin, Andrei S; Ionin, Andrey A; Kudryashov, Sergey I; Saltuganov, Pavel N

    2014-02-12

    Femtosecond laser treatment of a glass surface was used to fabricate a multimodal roughness having regular surface ripples with a period of a few micrometers decorated by aggregates of nearly spherical nanoparticles. UV-ozone treatment followed by chemisorption of the appropriate functional fluorosilanes onto the textured surface makes it possible to fabricate a superhydrophobic coating with a specific surface resistance on the order of petaohms on a glass surface. The main advantage of the fabricated coating under severe operating conditions with abrasion loads is the significant durability of its electro-insulating properties. The longevity of the high surface resistivity, even on long-term contact with a water vapor-saturated atmosphere, is directly related to the peculiarities of the surface texture and ripple structure.

  11. Comparative study on microstructure, crystallite size and lattice strain of as-deposited and thermal treatment silver silicon nitride coating on Ti6Al4V alloy

    NASA Astrophysics Data System (ADS)

    Zalilah, Umi; Mahmoodian, R.

    2017-06-01

    Silver silicon nitride coating were deposited on Ti6Al4V alloy using physical vapor deposition magnetron sputtering technique. Field Emission Spectroscopy (FESEM), Electron Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) were used to characterize as-deposited and after heat treatment of AgSiN coatings in order to understand the morphology, compositions and structure. Meanwhile, in determining the crystallite size and lattice strain, the simplified Williamson-Hall plot method was utilized. The heat treated coated sample shown to reveal granular surface structure, bigger crystallite size and lattice strain as compared to the as-deposited coated sample.

  12. Urban runoff treatment using nano-sized iron oxide coated sand with and without magnetic field applying

    PubMed Central

    2013-01-01

    Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, pH, nitrate and phosphate were controlled for investigate of system efficiency. The prepared column materials were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDXA) instruments. SEM and EDXA analyses proved that the sand has been coated with nano iron oxide (Fe3O4) successfully. The results of SEM and EDXA instruments well demonstrate the formation of nano iron oxide (Fe3O4) on sand particle. Removal efficiency without magnetic field for turbidity; Pb, Zn, Cd and PO4 were observed to be 90.8%, 73.3%, 75.8%, 85.6% and 67.5%, respectively. When magnetic field was applied, the removal efficiency for turbidity, Pb, Zn, Cd and PO4 was increased to 95.7%, 89.5%, 79.9%, 91.5% and 75.6% respectively. In addition, it was observed that coated sand and magnetic field was not able to remove NO3 ions. Statistical analyses of data indicated that there was a significant difference between removals of pollutants in two tested columns. Results of this study well demonstrate the efficiency of nanosized iron oxide-coated sand in treatment of urban runoff quality; upon 75% of pollutants could be removed. In addition, in the case of magnetic field system efficiency can be improved significantly. PMID:24360061

  13. Urban runoff treatment using nano-sized iron oxide coated sand with and without magnetic field applying.

    PubMed

    Khiadani Hajian, Mehdi; Zarrabi, Mansur; Foroughi, Maryam

    2013-12-20

    Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, pH, nitrate and phosphate were controlled for investigate of system efficiency. The prepared column materials were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDXA) instruments. SEM and EDXA analyses proved that the sand has been coated with nano iron oxide (Fe3O4) successfully. The results of SEM and EDXA instruments well demonstrate the formation of nano iron oxide (Fe3O4) on sand particle. Removal efficiency without magnetic field for turbidity; Pb, Zn, Cd and PO4 were observed to be 90.8%, 73.3%, 75.8%, 85.6% and 67.5%, respectively. When magnetic field was applied, the removal efficiency for turbidity, Pb, Zn, Cd and PO4 was increased to 95.7%, 89.5%, 79.9%, 91.5% and 75.6% respectively. In addition, it was observed that coated sand and magnetic field was not able to remove NO3 ions. Statistical analyses of data indicated that there was a significant difference between removals of pollutants in two tested columns. Results of this study well demonstrate the efficiency of nanosized iron oxide-coated sand in treatment of urban runoff quality; upon 75% of pollutants could be removed. In addition, in the case of magnetic field system efficiency can be improved significantly.

  14. Nanostructured Multilayer Composite Coatings on Ceramic Cutting Tools for Finishing Treatment of High-Hardness Quenched Steels

    NASA Astrophysics Data System (ADS)

    Vereshchaka, A. A.; Batako, A. D.; Sotova, E. S.; Vereshchaka, A. S.

    2016-01-01

    The functional role of nanostructured multilayer composite coatings (NMCC) deposited on the operating surfaces of replaceable faceted cutting inserts (CI) from cutting ceramics based on aluminum oxides with additives of titanium carbides is studied. It is shown that the developed NMCC not only raise substantially the endurance of the ceramic tools under high-speed dry treatment of quenched steels but also improve the quality and accuracy of processing of the parts and the ecological parameters of the cutting process.

  15. Report: Discussion on the development of nano Ag/TiO2 coating bracket and its antibacterial property and biocompatibility in orthodontic treatment.

    PubMed

    Zhang, Ronghe; Zhang, Weiwei; Bai, Xueyan; Song, Xiaotong; Wang, Chunyan; Gao, Xinxin; Tian, Xubiao; Liu, Fengzhen

    2015-03-01

    This paper aims to explore the antibacterial property of nano Ag/TiO2 coating bracket for the common bacteria in oral cavity, and discuss its biocompatibility. Micro morphology in the surface of nano Ag/TiO2 coating bracket was detected by scanning electron microscope (SEM), and surface roughness of ordinary mental bracket, nano TiO2 coating bracket and nano Ag/TiO2 coating bracket were measured. First, antibacterial property of nano Ag/TiO2 coating bracket on the common bacteria in oral cavity was studied by sticking membrane method. Secondly, bonding strength of nano TiO2 coating and nano Ag/TiO2 coating bracket in groups were detected by scratching test. The result showed that, the synthetic nano Ag/TiO2 coating was nanogranular films with rigorous organizational structure, presenting as smooth and clean surface, and antibacterial rate of nano Ag/TiO2 coating for the common bacteria in oral cavity for 20 min was more than 79% in the dark. All the findings suggested that, nano Ag/TiO2 coating bracket not only has antibacterial effect but also has good biocompatibility, therefore, it can satisfy the clinical request of orthodontic treatment.

  16. Anodic treatment of magnesium alloys, acid type, full coat. (SAE standard)

    SciTech Connect

    1995-02-01

    This specification establishes the engineering requirements for producing an acid-type, anodic coating on magnesium alloys and the properties of the coating. This process has been used typically to increase corrosion and abrasion resistance and to provide surfaces which will ensure maximum paint adheresion, but usage is not limited to such applications. This process is applicable to all magnesium alloys provided proper allowance is made for dimensional change.

  17. Effects of Al interlayer coating and thermal treatment on electron emission characteristics of carbon nanotubes deposited by electrophoretic method.

    PubMed

    Kim, Bu-Jong; Kim, Jong-Pil; Park, Jin-Seok

    2014-01-01

    The effects of aluminum (Al) interlayer coating and thermal post-treatment on the electron emission characteristics of carbon nanotubes (CNTs) were investigated. These CNTs were deposited on conical-shaped tungsten (W) substrates using an electrophoretic method. The Al interlayers were coated on the W substrates via magnetron sputtering prior to the deposition of CNTs. Compared with the as-deposited CNTs, the thermally treated CNTs revealed significantly improved electron emission characteristics, such as the decrease of turn-on electric fields and the increase of emission currents. The observations of Raman spectra confirmed that the improved emission characteristics of the thermally treated CNTs were ascribed to their enhanced crystal qualities. The coating of Al interlayers played a role in enhancing the long-term emission stabilities of the CNTs. The thermally treated CNTs with Al interlayers sustained stable emission currents without any significant degradation even after continuous operation of 20 h. The X-ray photoelectron spectroscopy (XPS) study suggested that the cohesive forces between the CNTs and the underlying substrates were strengthened by the coating of Al interlayers.

  18. Drug-coated balloon treatment of coronary artery disease: a position paper of the Italian Society of Interventional Cardiology.

    PubMed

    Cortese, Bernardo; Berti, Sergio; Biondi-Zoccai, Giuseppe; Colombo, Antonio; Limbruno, Ugo; Bedogni, Francesco; Cremonesi, Alberto; Silva, Pedro Leon; Sgueglia, Gregory A

    2014-02-15

    Drug-coated balloons are a new tool for the treatment of patients with coronary artery disease. The main feature of this technology is a rapid and homogenous transfer of an antiproliferative drug (paclitaxel) to the vessel wall just at the time of balloon inflation, when neointimal proliferation, in response to angioplasty, is the highest. Moreover, drug-coated balloons share adjuntive advantages over stents: the absence of permanent scaffold and polymer, the respect of the original coronary anatomy, and limited inflammatory stimuli, thereby allowing for short-term dual antiplatelet therapy. To this day, a lot of devices are available in the market, with limited scientific data for the vast majority of them. Thus, the Italian scientific society of interventional cardiologists GISE decided to coordinate the efforts of a group of reknown experts on the field, in order to obtain a Position Paper on the correct use of drug-coated balloons in all the settings of coronary artery disease, giving a class of indication to each one, based on the clinical evidence. This Position Paper represents a quick reference for operators, investigators, and manufactures to promote the understanding and the correct use of the drug-coated balloon technology in everyday clinical practice.

  19. Effects of Al interlayer coating and thermal treatment on electron emission characteristics of carbon nanotubes deposited by electrophoretic method

    PubMed Central

    2014-01-01

    The effects of aluminum (Al) interlayer coating and thermal post-treatment on the electron emission characteristics of carbon nanotubes (CNTs) were investigated. These CNTs were deposited on conical-shaped tungsten (W) substrates using an electrophoretic method. The Al interlayers were coated on the W substrates via magnetron sputtering prior to the deposition of CNTs. Compared with the as-deposited CNTs, the thermally treated CNTs revealed significantly improved electron emission characteristics, such as the decrease of turn-on electric fields and the increase of emission currents. The observations of Raman spectra confirmed that the improved emission characteristics of the thermally treated CNTs were ascribed to their enhanced crystal qualities. The coating of Al interlayers played a role in enhancing the long-term emission stabilities of the CNTs. The thermally treated CNTs with Al interlayers sustained stable emission currents without any significant degradation even after continuous operation of 20 h. The X-ray photoelectron spectroscopy (XPS) study suggested that the cohesive forces between the CNTs and the underlying substrates were strengthened by the coating of Al interlayers. PMID:24959105

  20. Overcoming the recalcitrance for the conversion of kenaf pulp to glucose via microwave-assisted pre-treatment processes.

    PubMed

    Ooi, Beng Guat; Rambo, Ashley L; Hurtado, Miguel A

    2011-01-01

    This study evaluates the pre-treatment of cellulose from kenaf plant to yield sugar precursors for the production of ethanol or butanol for use as biofuel additives. In order to convert the crystalline cellulosic form to the amorphous form that can undergo enzymatic hydrolysis of the glycosidic bond to yield sugars, kenaf pulp samples were subjected to two different pre-treatment processes. In the acid pre-treatment, the pulp samples were treated with 37.5% hydrochloric acid in the presence of FeCl(3) at 50 °C or 90 °C whereas in the alkaline method, the pulp samples were treated with 25% sodium hydroxide at room temperature and with 2% or 5% sodium hydroxide at 50 °C. Microwave-assisted NaOH-treatment of the cellulose was also investigated and demonstrated to be capable of producing high glucose yield without adverse environmental impact by circumventing the use of large amounts of concentrated acids i.e., 83-85% phosphoric acid employed in most digestion processes. The treated samples were digested with the cellulase enzyme from Trichoderma reesei. The amount of glucose produced was quantified using the Quantichrom(™) glucose bioassay for assessing the efficiency of glucose production for each of the treatment processes. The microwave-assisted alkaline pre-treatment processes conducted at 50 °C were found to be the most effective in the conversion of the crystalline cellulose to the amorphous form based on the significantly higher yields of sugar produced by enzymatic hydrolysis compared to the untreated sample.

  1. Diabetes mellitus and tuberculosis: pattern of tuberculosis, two-month smear conversion and treatment outcomes in Guangzhou, China.

    PubMed

    Mi, Fengling; Tan, Shouyong; Liang, Li; Harries, Anthony D; Hinderaker, Sven G; Lin, Yan; Yue, Wentao; Chen, Xi; Liang, Bing; Gong, Fang; Du, Jian

    2013-11-01

    There is a high burden of both diabetes (DM) and tuberculosis (TB) in China. We evaluated the association between DM and the pattern of disease, 2-month sputum smear conversion and treatment outcomes of patients with TB in Guangzhou, China. All patients registered with TB from September 2011 to June 2012 were screened for DM and assessed for treatment outcomes in relation to presence or absence of DM and quality of DM control using patient registers, treatment cards and electronic record systems. There were 1589 patients with TB of whom 189 (12%) had DM. Among those with DM, there was a significantly higher proportion of men, persons aged 35 years and older and persons with smear-positive pulmonary tuberculosis (PTB) (P < 0.01). In patients with DM and new smear-positive PTB, there was a higher proportion who had positive sputum smears at 2 months (21.7% vs. 5.6%, RR 3.85, 95%CI 2.24-6.63), who were lost-to-follow-up (5.2% vs. 1.7%, RR 3.23, 95%CI 1.08-9.63) and who failed treatment (10.3% vs. 2.3%, RR 4.46, 95%CI 1.96-10.18) compared with patients who had no DM. There was no significant association between these adverse outcomes and DM control as measured by 2 and 6-month fasting blood glucose. Diabetes mellitus in new smear-positive patients with PTB was associated with failure to sputum smear convert at 2 months and adverse treatment outcomes of loss-to-follow-up and failure. Further research is needed to understand the reasons for these findings and to determine whether the current length of treatment of 6 months is adequate. © 2013 John Wiley & Sons Ltd.

  2. Overcoming the Recalcitrance for the Conversion of Kenaf Pulp to Glucose via Microwave-Assisted Pre-Treatment Processes

    PubMed Central

    Ooi, Beng Guat; Rambo, Ashley L.; Hurtado, Miguel A.

    2011-01-01

    This study evaluates the pre-treatment of cellulose from kenaf plant to yield sugar precursors for the production of ethanol or butanol for use as biofuel additives. In order to convert the crystalline cellulosic form to the amorphous form that can undergo enzymatic hydrolysis of the glycosidic bond to yield sugars, kenaf pulp samples were subjected to two different pre-treatment processes. In the acid pre-treatment, the pulp samples were treated with 37.5% hydrochloric acid in the presence of FeCl3 at 50 °C or 90 °C whereas in the alkaline method, the pulp samples were treated with 25% sodium hydroxide at room temperature and with 2% or 5% sodium hydroxide at 50 °C. Microwave-assisted NaOH-treatment of the cellulose was also investigated and demonstrated to be capable of producing high glucose yield without adverse environmental impact by circumventing the use of large amounts of concentrated acids i.e., 83–85% phosphoric acid employed in most digestion processes. The treated samples were digested with the cellulase enzyme from Trichoderma reesei. The amount of glucose produced was quantified using the Quantichrom™ glucose bioassay for assessing the efficiency of glucose production for each of the treatment processes. The microwave-assisted alkaline pre-treatment processes conducted at 50 °C were found to be the most effective in the conversion of the crystalline cellulose to the amorphous form based on the significantly higher yields of sugar produced by enzymatic hydrolysis compared to the untreated sample. PMID:21673900

  3. Influence of phytic acid concentration on coating properties obtained by MAO treatment on magnesium alloys

    NASA Astrophysics Data System (ADS)

    Zhang, R. F.; Zhang, S. F.; Duo, S. W.

    2009-06-01

    Anodic coatings were prepared by microarc oxidation (MAO) on AZ91HP in a base solution of 10 g/L NaOH with and without the addition of 0-12 g/L phytic acid (C 6H 18O 24P 6). The influences of C 6H 18O 24P 6 and its concentration on the conductivity and breakdown voltage were studied. The morphologies and compositions of anodic coatings were determined by environmental scanning electron microscope (ESEM) and energy dispersive X-ray spectroscopy (EDX). Potentiodynamic polarization test was performed in 3.5 wt.% NaCl solution to evaluate the corrosion resistance of anodic coatings. The results showed that with the increase of C 6H 18O 24P 6 concentration, the solution conductivity decreased while the values of breakdown voltage increased. EDX analysis showed that the coatings formed in solutions with C 6H 18O 24P 6 addition contained Mg, Al, O, C, P and a trance of Na. The addition of C 6H 18O 24P 6 into the base solution was helpful in coating formation and the coatings formed in the solution containing 8 g/L C 6H 18O 24P 6 exhibited the best pore uniformity and corrosion resistance.

  4. Advanced treatment of cephalosporin pharmaceutical wastewater by nano-coated electrode and perforated electrode.

    PubMed

    Yang, Bo; Zuo, Jiane; Gan, Lili; Yu, Xin; Liu, Fenglin; Tang, Xinyao; Wang, Yajiao

    2014-09-19

    The objective of this study was to investigate the degradation of nonbiodegradable organic pollutants in biologically cephalosporin pharmaceutical wastewater using different electrodes such as non-nano-scale electrode (traditional coated), nano-scale (nano-coated) electrode, and perforated electrode after biotreatment. The traditional coated electrode plate, nano-coated electrode plate, and two different perforated titanium dioxide (TiO2) electrode plates with an average pore size of 10 μm and 20 μm were chosen as the anode. The results demonstrated that traditional coated electrode, nano-scale electrode, and perforated electrode could effectively remove nonbiodegradable organic pollutants from pharmaceutical wastewater. The perforated electrode with an average pore size of 10 μm exhibited the best degradation effect with a 90 % decrease in the chemical oxygen demand (COD) (COD content reduced from 320 mg L(-1) to 32 mg L(-1)). During catalytic degradation, the electrical conductivity of pharmaceutical wastewater increased and the pH increased and finally reached equilibrium. It was also found that the perforated TiO2 electrode produced relatively large amounts of dissolved oxygen during the catalytic oxidation process, reaching above 4 mg L(-1), whereas the nano-coated electrode produced little dissolved oxygen. The biotoxicities of all wastewater samples increased firstly then decreased slightly during the electrical catalytic oxidation, but the final biotoxicities were all higher than initial ones.

  5. An eccentrically coated asymmetric antenna applicator for intracavitary hyperthermia treatment of cancer.

    PubMed

    Manry, C W; Broschat, S L; Chou, C K; McDougall, J A

    1992-09-01

    In this paper a model based on transmission line theory is used to predict the behavior of an eccentrically coated asymmetric antenna applicator for use in intracavitary hyperthermia. Theoretical results for the heating rate (HR) of the applicators are compared to experimental results. The experimental results were obtained at City of Hope National Medical Center using four different 915-MHz applicators, each with a different antenna size and eccentricity of the coating. A parameter delta is defined where delta < 1.0 is a thin wire approximation; delta is primarily a function of the eccentricity of the coating, the antenna diameter, and the coating diameter. It is found that when delta approximately less than 0.5, the theoretical model works well. In particular, it predicts the directivity due to the eccentricity of the coating. However, as this eccentricity is increased or as the antenna diameter is increased (delta approximately greater than 0.6), the model no longer accurately predicts directivity. Thus, the model that can be used to predict the HR profiles for an eccentrically coated asymmetric antenna only when delta approximately less than 0.5.

  6. Characterization of the chemical conversion films that form on Mg-Al alloy in colloidal silica solution

    NASA Astrophysics Data System (ADS)

    Kim, Seong-Jong; Zhou, Ying; Ichino, Ryoichi; Okido, Masazumi; Tanikawa, Shoji

    2003-04-01

    Chemical conversion treatment of Mg-Al alloy (AZ91) using colloidal silica as an alternative to chromate conversion was investigated as a function of solution pH, temperature, solution conditions, and treatment time. The solution used for the colloidal silica coating consisted of colloidal silica, titanium sulfate, and cobalt ions to maintain good anti-corrosion and adhesion properties. Adding CoSO4 to the colloidal silica solution enhanced the adhesion force between the silica film and magnesium substrate. The optimum conditions for the chemical conversion treatment solution were pH 2, 90-sec treatment, and 25°C.

  7. One step conversion of wheat straw to sugars by simultaneous ball milling, mild acid, and fungus Penicillium simplicissimum treatment.

    PubMed

    Yuan, Li; Chen, Zhenhua; Zhu, Yonghua; Liu, Xuanming; Liao, Hongdong; Chen, Ding

    2012-05-01

    Wheat straw is one of the major lignocellulosic plant residues in many countries including China. An attractive alternative is the utilization of wheat straw for bioethanol production. This article mainly studies a simple one-step wet milling with Penicillium simplicissimum and weak acid to hydrolysis of wheat straw. The optimal condition for hydrolysis was ball milling 48 h in citrate solvent (pH = 4) with P. simplicissimum H5 at the speed of 500 rpm and the yield of sugar increased with increased milling time. Corresponding structure transformations before and after milling analyzed by X-ray diffraction, transmission Fourier transform infrared spectroscopy, and environmental scanning electron microscopy clearly indicated that this combined treatment could be attributed to the crystalline and chemical structure changes of cellulose in wheat straw during ball milling. This combined treatment of ball milling, mild acid, and fungus hydrolysis enabled the conversion of the wheat straw. Compared with traditional method of ball milling, this work showed a more simple, novel, and environmentally friendly way in mechanochemical treatment of wheat straw.

  8. Neoadjuvant and conversion treatment of patients with colorectal liver metastasis: the potential role of bevacizumab and other antiangiogenic agents.

    PubMed

    García-Alfonso, Pilar; Ferrer, Ana; Gil, Silvia; Dueñas, Rosario; Pérez, María Teresa; Molina, Raquel; Capdevila, Jaume; Safont, María José; Castañón, Carmen; Cano, Juana María; Lara, Ricardo

    2015-12-01

    More than 50 % of patients with colorectal cancer develop liver metastases. Surgical resection is the only available treatment that improves survival in patients with colorectal liver metastases (CRLM). New antiangiogenic targeted therapies, such as bevacizumab, aflibercept, and regorafenib, in combination with neoadjuvant and conversion chemotherapy may lead to improved response rates in this population of patients and increase the proportion of patients eligible for surgical resection. The present review discusses the available data for antiangiogenic targeted agents in this setting. One of these therapies, bevacizumab, which targets the vascular endothelial growth factor (VEGF) has demonstrated good results in this setting. In patients with initially unresectable CRLM, the combination of 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) plus bevacizumab has led to high response and resection rates. This combination is also effective for patients with unresectable CRLM. Moreover, the addition of bevacizumab to chemotherapy in the neoadjuvant setting of liver metastasis has a higher impact on pathological response rate. This drug also has a manageable safety profile, and according to recent data, bevacizumab may protect against the sinusoidal dilation provoked in the liver by certain cytotoxic agents. In phase II trials, antiangiogenic therapy has demonstrated benefits in the presurgical treatment of CRLM and may represent a new treatment pathway for these patients.

  9. Fracture resistance of dental nickel-titanium rotary instruments with novel surface treatment: Thin film metallic glass coating.

    PubMed

    Chi, Chih-Wen; Deng, Yu-Lun; Lee, Jyh-Wei; Lin, Chun-Pin

    2017-05-01

    Dental nickel-titanium (NiTi) rotary instruments are widely used in endodontic therapy because they are efficient with a higher success rate. However, an unpredictable fracture of instruments may happen due to the surface characteristics of imperfection (or irregularity). This study assessed whether a novel surface treatment could increase fatigue fracture resistance of dental NiTi rotary instruments. A 200- or 500-nm thick Ti-zirconium-boron (Ti-Zr-B) thin film metallic glass was deposited on ProTaper Universal F2 files using a physical vapor deposition process. The characteristics of coating were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry. In cyclic fatigue tests, the files were performed in a simulated root canal (radius=5 mm, angulation=60°) under a rotating speed of 300rpm. The fatigue fractured cross sections of the files were analyzed with their fractographic performances through scanning electron microscopy images. The amorphous structure of the Ti-Zr-B coating was confirmed by transmission electron microscopy and X-ray diffractometry. The surface of treated files presented smooth morphologies without grinding irregularity. For the 200- and 500-nm surface treatment groups, the coated files exhibited higher resistance of cyclic fatigue than untreated files. In fractographic analysis, treated files showed significantly larger crack-initiation zone; however, no significant differences in the areas of fatigue propagation and catastrophic fracture were found compared to untreated files. The novel surface treatment of Ti-Zr-B thin film metallic glass on dental NiTi rotary files can effectively improve the fatigue fracture resistance by offering a smooth coated surface with amorphous microstructure. Copyright © 2016. Published by Elsevier B.V.

  10. Randomized Trial of a Family-based, Automated, Conversational Obesity Treatment Program for Underserved Populations

    PubMed Central

    Wright, J. A.; Phillips, B.D.; Watson, B.L.; Newby, P.K.; Norman, G. J.; Adams, W.G.

    2013-01-01

    Objective To evaluate the acceptability and feasibility of a scalable obesity treatment program integrated with pediatric primary care and delivered using interactive voice technology (IVR) to families from underserved populations. Design and Methods Fifty parent-child dyads (child 9–12 yrs, BMI >95th percentile) were recruited from a pediatric primary care clinic and randomized to either an IVR or a wait-list control (WLC) group. The majority were lower-income, African-American (72%) families. Dyads received IVR calls for 12 weeks. Call content was informed by two evidenced-based interventions. Anthropometric and behavioral variables were assessed at baseline and 3 mo follow-up. Results Forty-three dyads completed the study. IVR parents ate 1 cup more fruit than WLC (p < .05). No other groups differences were found. Children classified as high users of the IVR decreased weight, BMI and BMI z-score compared to low users (p<.05). Mean number of calls for parents and children were 9.1 (5.2 SD) and 9.0 (5.7 SD), respectively. Of those who made calls, >75% agreed that the calls were useful, made for people like them, credible, and helped them eat healthy foods. Conclusion An obesity treatment program delivered via IVR may be an acceptable and feasible resource for families from underserved populations. PMID:23512915

  11. Applications of nano-structured metal oxides for treatment of arsenic in water and for antimicrobial coatings

    NASA Astrophysics Data System (ADS)

    Sadu, Rakesh Babu

    Dependency of technology has been increasing radically through cellular phones for communication, data storage devices for education, drinking water purifiers for healthiness, antimicrobial-coated textiles for cleanliness, nanomedicines for deadliest diseases, solar cells for natural power, nanorobots for engineering and many more. Nanotechnology develops many unprecedented products and methodologies with its adroitness in this modern scientific world. Syntheses of nanomaterials play a significant role in the development of technology. Solution combustion and hydrothermal syntheses produce many nanomaterials with different structures and pioneering applications. Nanometal oxides, like titania, silver oxide, manganese oxide and iron oxide have their unique applications in engineering, chemistry and biochemistry. Likewise, this study talks about the syntheses and applications of nanomaterials such as magnetic graphene nanoplatelets (M-Gras) decorated with uniformly dispersed NPs, manganese doped titania nanotubes (Mn-TNTs), and silver doped titania nanopartcles (nAg-TNPs) and their polyurethane based polymer nanocomposite coating (nAg-TiO2 /PU). Basically, M-Gras, and Mn-TNTs were applied for the treatment of arsenic contaminated water, and nAg- TiO2/PU applied for antimicrobial coatings on textiles. Adsorption of arsenic over Mn- TNTs, and M-Gras was discussed while considering all the regulations of arsenic contamination in drinking water and oxidation of arsenic over Mn-TNTs also discussed with the possible surface reactions. Silver doped titania and its polyurethane nanocomposite was coated on polyester fabric and examined the coated fabric for bactericidal activity for gram-negative (E. coli) and gram-positive ( S. epidermidis) bacteria. This study elucidates the development of suitable nanomaterials and their applications to treat or rectify the environmental hazards while following the scientific standards and regulations.

  12. [The setting in observation and involuntary treatments: a conversation between the law and medicine].

    PubMed

    Leistedt, S J

    2013-09-01

    The law of June 26, 1990 (protection measure of the mental patients) has replaced the old law of collocation of 1850 (review in 1873). Conceived in the line of the principles of the European Convention of the Humans right, it constitutes an important reform of the involuntary treatment of the mental patients and recalls, without any doubt, that the patient is prone of right. The article describes the scope of application of the law of June 26, 1990, and the methods of initiation of a protection measure. Then, the measure in a hospital environment (ordinary procedure and urgent procedure), as well as the measure in a family environment are approached in their waning. Furthermore, the author discusses the networks between physicians and lawyers and the difficulty to communicate between these two worlds, such as Justice and Medicine.

  13. Alkaline hydrothermal conversion of fly ash filtrates into zeolites 2: utilization in wastewater treatment.

    PubMed

    Somerset, Vernon; Petrik, Leslie; Iwuoha, Emmanuel

    2005-01-01

    Filtrates were collected using a codisposal reaction wherein fly ash was reacted with acid mine drainage. These codisposal filtrates were then analyzed by X-ray Fluorescence spectrometry for quantitative determination of the SiO2 and Al2O3 content. Alkaline hydrothermal zeolite synthesis was then applied to the filtrates to convert the fly ash material into zeolites. The zeolites formed under the experimental conditions were faujasite, sodalite, and zeolite A. The use of the fly ash-derived zeolites and a commercial zeolite was explored in wastewater decontamination experiments as it was applied to acid mine drainage in different dosages. The concentrations of Ni, Zn, Cd, As, and Pb metal ions in the treated wastewater were investigated. The results of the treatment of the acid mine drainage with the prepared fly ash zeolites showed that the concentrations of Ni, Zn, Cd, and Hg were decreased as the zeolite dosages of the fly ash zeolite (FAZ1) increased.

  14. Novel Buccal Film Formulation of Buprenorphine-Naloxone for the Maintenance Treatment of Opioid Dependence: A 12-Week Conversion Study.

    PubMed

    Sullivan, James G; Webster, Lynn

    2015-05-01

    The purpose of this study was to provide a preliminary assessment of the safety, tolerability, symptom control, and acceptability of buprenorphine-naloxone buccal film (BBN) for the maintenance treatment of opioid dependence in patients converted from buprenorphine-naloxone sublingual tablet or film (SLBN), as well as to determine the conversion ratio for switching patients from SLBN to BBN. This open-label study included adult opioid-dependent subjects stabilized on 8/2 to 32/8 mg/d of SLBN for a minimum of 30 days. Study subjects were converted to a bioequivalent dose of BBN and maintained for 12 weeks. A total of 249 subjects (mean age 38.7 years, 65.9% male) were converted from SLBN to a single daily dose of BBN, and 79.1% completed the 12-week study. Adverse events and withdrawal symptoms led to discontinuation in 2.4% and 2.0% of BBN-treated subjects, respectively. Rates of constipation reported at baseline declined from 41% just before the initial BBN dose and within 24 hours of the last SLBN dose to 13% after 12 weeks of BBN treatment; treatment-emergent constipation was reported by 2.8% of BBN-treated subjects. Oral mucosal abnormalities were identified in 5% and 0.6% of systematic oral examinations in SLBN- and BBN-treated subjects, respectively. A total of 34 subjects had Clinical Opiate Withdrawal Scale total scores ranging from 10 to 25 (overall mean, 13.8) within 24 hours of taking their last SLBN dose, and scores for these subjects were reduced to a range of 0 to 3 (overall mean, 0.7) at 3 hours after the initial dose of BBN. Treatment compliance was high (108%); <1% of urine samples were buprenorphine-free, and 92.4% of BBN-treated subjects did not have a urine sample that tested positive for a non-prescribed opioid. A total of 91.3% subjects rated the taste of BBN as pleasant or neutral, and 82.5% rated BBN ease of use as easy or neutral. The overall mean final dose of BBN was 8.0/1.4 mg/d, yielding a 2:1 buprenorphine conversion ratio. Although

  15. The use of effective treatments: the case of an adolescent girl with anorexia nervosa in the context of a conversion disorder.

    PubMed

    Goldstein, Mandy; Madden, Sloane; Peters, Lorna

    2013-04-01

    The use of empirically supported treatment (EST) has been shown to enhance treatment outcome. The purpose of this case study was to suggest that ESTs further encourage effective reconceptualisation and the ongoing delivery of effective treatment, especially in the case of complex or atypical presentations or response to treatment. This report describes the case of an adolescent girl who underwent Maudsley family-based treatment for anorexia nervosa (AN) for a period of 12 months. Atypical response lead to an understanding of her presentation as representing a primary conversion disorder, within which AN symptoms were conceptualised as another somatic conversion of emotional distress. The report details her clinical presentation and management over the course of her illness. The case offers an important opportunity to explore the central role of the use of ESTs in guiding effective treatment delivery.

  16. Preparation of soft magnetic composites for Fe particles coated with (NiZn)Fe2O4 via microwave treatment

    NASA Astrophysics Data System (ADS)

    Peng, Yuandong; Nie, Junwu; Zhang, Wenjun; Bao, Chongxi; Ma, Jian; Cao, Yang

    2015-12-01

    Soft magnetic composites (SMCs) of Fe particles coated with fine particle Ni0.5Zn0.5Fe2O4 ferrite were prepared via microwave heat treatment, and the magnetic properties and microstructures of these composites were investigated. The results show that a well-distributed Ni0.5Zn0.5Fe2O4 coating layer was formed on the surface of the Fe particles upon microwave annealing. The SMCs sample treated by microwave heating at 800 °C for 30 min under N2 had a perfect insulation layer between the Fe particles and showed stable permeability and low core loss as well as good magnetic characteristics over a wide frequency range.

  17. Transparent ultra water-repellent poly(ethylene terephthalate) substrates fabricated by oxygen plasma treatment and subsequent hydrophobic coating

    NASA Astrophysics Data System (ADS)

    Teshima, Katsuya; Sugimura, Hiroyuki; Inoue, Yasushi; Takai, Osamu; Takano, Atsushi

    2005-05-01

    Wettability of solid surfaces with water is well-known to be governed by chemical properties and nanotextures of the surfaces. A proper nanotexture of surfaces enhances their hydrophobicity. In this study, a novel method consisting of two dry process techniques, that is, nanotexturing by an oxygen plasma treatment and subsequent hydrophobic coating by means of low temperature chemical vapor deposition or plasma-enhanced chemical vapor deposition, was employed to form ultra water-repellent polymer sheets. A nanotexture was formed on a poly(ethylene terephthalate) substrate surface via selective oxygen plasma etching. This surface nanotexture remained after the hydrophobic coatings using organosilane precursors. The surface-modified substrate was transparent and ultra water-repellent, showing a water contact angle greater than 150°.

  18. Effect of Age-Hardening Treatment on Microstructure and Sliding Wear-Resistance Performance of WC/Cu-Ni-Mn Composite Coatings

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Yang, Shuai; Liu, Kai; Gui, Chibin; Xia, Weisheng

    2017-06-01

    The Cu-Ni-Mn alloy-based hardfacing coatings reinforced by WC particles (WC/Cu-Ni-Mn) were deposited on a steel substrate by a manual oxy-acetylene weld hardfacing method. A sound interfacial junction was formed between the WC particles and the Cu-Ni-Mn alloy metal matrix binder even after the age-hardening treatment. The friction and wear behavior of the hardfacing coatings was investigated. With the introduction of WC particles, the sliding wear resistance of the WC/Cu-Ni-Mn hardfacing coatings was sharply improved: more than 200 times better than that of the age-hardening-treated Cu-Ni-Mn alloy coating. The sliding wear resistances of the as-deposited and the age-hardening-treated WC/Cu-Ni-Mn hardfacing coatings were 1.83 and 2.26 times higher than that of the commercial Fe-Cr-C hardfacing coating, which is mainly ascribed to the higher volume fraction of carbide reinforcement. Owing to the precipitation of the NiMn secondary phase in the Cu-Ni-Mn metal matrix, the age-hardening-treated coating had better wear resistance than that of the as-deposited coating. The main sliding wear mechanisms of the age-hardening-treated coatings are adhesion and abrasion.

  19. A Novel Strategy for Preparation of Si-HA Coatings on C/C Composites by Chemical Liquid Vaporization Deposition/Hydrothermal Treatments.

    PubMed

    Xin-Bo, Xiong; Xin-Ye, Ni; Ya-Yun, Li; Cen-Cen, Chu; Ji-Zhao, Zou; Xie-Rong, Zeng

    2016-08-05

    A novel strategy for the preparation of Si-doped hydroxyapatite (Si-HA) coatings on H2O2-treated carbon/carbon composites (C/C) was developed. HA coating was prepared on C/C through chemical liquid vaporization deposition (CLVD)/hydrothermal treatment. HA coating was immersed in an H2SiO3 solution at an autoclave at 413 K for transformation into Si-HA coating. The effects of H2SiO3 mass contents on the phase, morphology, and composition of the Si-HA coatings were studied through SEM, EDS,XRD, and FTIR. Their bonding performance to C/C was measured through a scratch test. Under the optimal content condition, the in vitro skull osteoblast response behaviors of the Si-HA coating were evaluated. Results showed that SiO3(2-) could enter into the HA lattice and occupy the PO4(3-) sites. Doped SiO3(2-) significantly improved the bonding performance of the HA coating to C/C in comparison with the untreated HA. The adhesive strength of the coatings initially increased and then decreased with increasing H2SiO3 content. Meanwhile, the cohesive strength of the Si-HA coatings was almost nearly identical. The Si-HA coating achieved at a content of 90% H2SiO3 exhibited the best bonding performance, and its osteoblast compatibility in vitro was superior to that of the untreated HA coating on C/C through CLVD/hydrothermal treatment.

  20. A Novel Strategy for Preparation of Si-HA Coatings on C/C Composites by Chemical Liquid Vaporization Deposition/Hydrothermal Treatments

    PubMed Central

    Xin-bo, Xiong; Xin-ye, Ni; Ya-yun, Li; Cen-cen, Chu; Ji-zhao, Zou; Xie-rong, Zeng

    2016-01-01

    A novel strategy for the preparation of Si-doped hydroxyapatite (Si-HA) coatings on H2O2-treated carbon/carbon composites (C/C) was developed. HA coating was prepared on C/C through chemical liquid vaporization deposition (CLVD)/hydrothermal treatment. HA coating was immersed in an H2SiO3 solution at an autoclave at 413 K for transformation into Si-HA coating. The effects of H2SiO3 mass contents on the phase, morphology, and composition of the Si-HA coatings were studied through SEM, EDS,XRD, and FTIR. Their bonding performance to C/C was measured through a scratch test. Under the optimal content condition, the in vitro skull osteoblast response behaviors of the Si-HA coating were evaluated. Results showed that SiO32− could enter into the HA lattice and occupy the PO43− sites. Doped SiO32− significantly improved the bonding performance of the HA coating to C/C in comparison with the untreated HA. The adhesive strength of the coatings initially increased and then decreased with increasing H2SiO3 content. Meanwhile, the cohesive strength of the Si-HA coatings was almost nearly identical. The Si-HA coating achieved at a content of 90% H2SiO3 exhibited the best bonding performance, and its osteoblast compatibility in vitro was superior to that of the untreated HA coating on C/C through CLVD/hydrothermal treatment. PMID:27492664

  1. A Novel Strategy for Preparation of Si-HA Coatings on C/C Composites by Chemical Liquid Vaporization Deposition/Hydrothermal Treatments

    NASA Astrophysics Data System (ADS)

    Xin-Bo, Xiong; Xin-Ye, Ni; Ya-Yun, Li; Cen-Cen, Chu; Ji-Zhao, Zou; Xie-Rong, Zeng

    2016-08-01

    A novel strategy for the preparation of Si-doped hydroxyapatite (Si-HA) coatings on H2O2-treated carbon/carbon composites (C/C) was developed. HA coating was prepared on C/C through chemical liquid vaporization deposition (CLVD)/hydrothermal treatment. HA coating was immersed in an H2SiO3 solution at an autoclave at 413 K for transformation into Si-HA coating. The effects of H2SiO3 mass contents on the phase, morphology, and composition of the Si-HA coatings were studied through SEM, EDS,XRD, and FTIR. Their bonding performance to C/C was measured through a scratch test. Under the optimal content condition, the in vitro skull osteoblast response behaviors of the Si-HA coating were evaluated. Results showed that SiO32‑ could enter into the HA lattice and occupy the PO43‑ sites. Doped SiO32‑ significantly improved the bonding performance of the HA coating to C/C in comparison with the untreated HA. The adhesive strength of the coatings initially increased and then decreased with increasing H2SiO3 content. Meanwhile, the cohesive strength of the Si-HA coatings was almost nearly identical. The Si-HA coating achieved at a content of 90% H2SiO3 exhibited the best bonding performance, and its osteoblast compatibility in vitro was superior to that of the untreated HA coating on C/C through CLVD/hydrothermal treatment.

  2. Preparation and properties of plasma electrolytic oxidation coating on sandblasted pure titanium by a combination treatment.

    PubMed

    Wang, Hong-Yuan; Zhu, Rui-Fu; Lu, Yu-Peng; Xiao, Gui-Yong; Zhao, Xing-Chuan; He, Kun; Yuan, Y F; Li, Ying; Ma, Xiao-Ni

    2014-09-01

    Plasma electrolytic oxidation (PEO) is one of the most applicable methods to produce bioceramic coating on a dental implant and sandblasting is a primary technique to modify metal surface properties. This study aims to deposit bioceramic Ca- and P-containing coatings on sandblasted commercially pure titanium by PEO technique to improve its bioactive performance. The time-dependent modified surfaces are characterized in terms of their microstructure, phase, chemical composition, mechanical properties and bioactivities. The results show that the combination-treated coating exhibits better properties than the PEO-treated one, especially in bioactivities, as evidenced by the HA formation after immersion in simulated body fluid (SBF) for 5 days and the cell viability after seeding for 1 or 3 days. The enhancement of the modified surface is attributed to a combination of the mechanical sandblasting and the microplasma oxidation.

  3. Conversational Dominance.

    ERIC Educational Resources Information Center

    Esau, Helmut; Poth, Annette

    Details of conversational behavior can often not be interpreted until the social interaction, including the rights and obligations of the participants, their intent, the topic, etc., has been defined. This paper presents a model of conversation in which the conversational image a person presents in a given conversational situation is a function of…

  4. Simultaneous spin-coating and solvent annealing: Manipulating the active layer morphology to a power conversion efficiency of 9.6% in polymer solar cells

    DOE PAGES

    He, Zhicai; Liu, Feng; Wang, Cheng; ...

    2015-08-20

    Here, we developed a simultaneous spin-coating/solvent-annealing process and demonstrated morphology optimization for PTB7 based organic photovoltaics. This novel processing method enhances the edge-on crystalline content in thin films and induces the formation of weak PCBM aggregates. As a result, the efficiency of polymer solar cells increased from 9.2% to a certified high efficiency of 9.61%, owing to an enhanced short-circuit current (Jsc, 18.4 mA cm–2vs. 17. 5 mA cm–2) and an improved fill factor.

  5. Simultaneous spin-coating and solvent annealing: Manipulating the active layer morphology to a power conversion efficiency of 9.6% in polymer solar cells

    SciTech Connect

    He, Zhicai; Liu, Feng; Wang, Cheng; Chen, Jihua; He, Lilin; Nordlund, Dennis; Wu, Hongbin; Russell, Thomas P.; Cao, Yong

    2015-08-20

    Here, we developed a simultaneous spin-coating/solvent-annealing process and demonstrated morphology optimization for PTB7 based organic photovoltaics. This novel processing method enhances the edge-on crystalline content in thin films and induces the formation of weak PCBM aggregates. As a result, the efficiency of polymer solar cells increased from 9.2% to a certified high efficiency of 9.61%, owing to an enhanced short-circuit current (Jsc, 18.4 mA cm–2vs. 17. 5 mA cm–2) and an improved fill factor.

  6. Restoring a sludge holding tank at a wastewater treatment plant using high-performance coatings

    SciTech Connect

    O'Dea, V.

    2005-11-01

    Faced with a serious hydrogen sulfide (H{sub 2}S) corrosion problem in two sludge holding tanks in 1993, the city of Concord, New Hampshire, repaired the deteriorating substrate by using a conventional acrylic-modified cementitious resurfacer and a coal tar epoxy (CTE) coating system. CTE failure occurred within 2 years, leading to more severe coating delamination. Restoration was delayed for 10 years, which caused extensive chemical attack on the concrete substrate-upwards of 2 in. (50 mm) of concrete loss. This article explains how one of these tanks was restored and prepared for another 15+ years of service.

  7. Heat Treatment Used to Strengthen Enabling Coating Technology for Oil-Free Turbomachinery

    NASA Technical Reports Server (NTRS)

    Edmonds, Brian J.; DellaCorte, Christopher

    2002-01-01

    The PS304 high-temperature solid lubricant coating is a key enabling technology for Oil- Free turbomachinery propulsion and power systems. Breakthroughs in the performance of advanced foil air bearings and improvements in computer-based finite element modeling techniques are the key technologies enabling the development of Oil-Free aircraft engines being pursued by the Oil-Free Turbomachinery team at the NASA Glenn Research Center. PS304 is a plasma spray coating applied to the surface of shafts operating against foil air bearings or in any other component requiring solid lubrication at high temperatures, where conventional materials such as graphite cannot function.

  8. Initial implementation of the conversion from the energy-subtracted CT number to electron density in tissue inhomogeneity corrections: An anthropomorphic phantom study of radiotherapy treatment planning

    SciTech Connect

    Tsukihara, Masayoshi; Noto, Yoshiyuki; Sasamoto, Ryuta; Hayakawa, Takahide; Saito, Masatoshi

    2015-03-15

    Purpose: To achieve accurate tissue inhomogeneity corrections in radiotherapy treatment planning, the authors had previously proposed a novel conversion of the energy-subtracted computed tomography (CT) number to an electron density (ΔHU–ρ{sub e} conversion), which provides a single linear relationship between ΔHU and ρ{sub e} over a wide range of ρ{sub e}. The purpose of this study is to present an initial implementation of the ΔHU–ρ{sub e} conversion method for a treatment planning system (TPS). In this paper, two example radiotherapy plans are used to evaluate the reliability of dose calculations in the ΔHU–ρ{sub e} conversion method. Methods: CT images were acquired using a clinical dual-source CT (DSCT) scanner operated in the dual-energy mode with two tube potential pairs and an additional tin (Sn) filter for the high-kV tube (80–140 kV/Sn and 100–140 kV/Sn). Single-energy CT using the same DSCT scanner was also performed at 120 kV to compare the ΔHU–ρ{sub e} conversion method with a conventional conversion from a CT number to ρ{sub e} (Hounsfield units, HU–ρ{sub e} conversion). Lookup tables for ρ{sub e} calibration were obtained from the CT image acquisitions for tissue substitutes in an electron density phantom (EDP). To investigate the beam-hardening effect on dosimetric uncertainties, two EDPs with different sizes (a body EDP and a head EDP) were used for the ρ{sub e} calibration. Each acquired lookup table was applied to two radiotherapy plans designed using the XiO TPS with the superposition algorithm for an anthropomorphic phantom. The first radiotherapy plan was for an oral cavity tumor and the second was for a lung tumor. Results: In both treatment plans, the performance of the ΔHU–ρ{sub e} conversion was superior to that of the conventional HU–ρ{sub e} conversion in terms of the reliability of dose calculations. Especially, for the oral tumor plan, which dealt with dentition and bony structures, treatment

  9. Nanocrystalline ceria coatings on solid oxide fuel cell anodes: the role of organic surfactant pretreatments on coating microstructures and sulfur tolerance

    PubMed Central

    Wu, Chieh-Chun; Tang, Ling

    2014-01-01

    Summary Treatments with organic surfactants, followed by the deposition of nanocrystalline ceria coatings from aqueous solution, were applied to anodes of solid oxide fuel cells. The cells were then operated in hydrogen/nitrogen fuel streams with H2S contents ranging from 0 to 500 ppm. Two surfactant treatments were studied: immersion in dodecanethiol, and a multi-step conversion of a siloxy-anchored alkyl bromide to a sulfonate functionality. The ceria coatings deposited after the thiol pretreatment, and on anodes with no pretreatment, were continuous and uniform, with thicknesses of 60–170 nm and 100–140 nm, respectively, and those cells exhibited better lifetime performance and sulfur tolerance compared to cells with untreated anodes and anodes with ceria coatings deposited after the sulfonate pretreatment. Possible explanations for the effects of the treatments on the structure of the coatings, and for the effects of the coatings on the performance of the cells, are discussed. PMID:25383282

  10. Microarc Oxidation Coating Combined with Surface Pore-Sealing Treatment Enhances Corrosion Fatigue Performance of 7075-T7351 Al Alloy in Different Media

    PubMed Central

    Yang, Hui-Hui; Wang, Xi-Shu; Wang, Ya-Ming; Wang, Yan-Ling; Zhang, Zhi-Hao

    2017-01-01

    Rotating bending fatigue tests have been performed to evaluate the corrosion fatigue performance and its influence factors of 7075-T7351 Al alloy in different media, namely air and a 5.0 wt % NaCl aqueous solution. All samples were coated by microarc oxidation (MAO) coating technology; some samples were followed by an epoxy resin pore-sealing treatment. Microscopic analyses of the surfaces and fracture cross-sections of samples were carried out. The results reveal that the sample with a MAO coating of 10 μm thickness and pore-sealing treatment by epoxy resin possesses optimal corrosion fatigue performance in the different media. The MAO coating with a pore-sealing treatment significantly improves the corrosion fatigue limit of 7075-T7351 Al alloy. PMID:28772970

  11. Super-amphiphilic surface of nano silica/polyurethane hybrid coated PET film via a plasma treatment.

    PubMed

    Bui, Van-Tien; Liu, Xuyan; Ko, Seung Hyeon; Choi, Ho-Suk

    2015-09-01

    This study first reports the fabrication of a super-amphiphilic surface using PET films with a silica-polyurethane hybrid top-coat layer through a non-thermal, one-atmospheric-pressure plasma treatment. This surface displays contact angle close to zero with both aqueous and oily liquids, which has attracted enormous attention for a wide-range of practical applications. We systematically investigated the influence of the plasma treatment time on the wetting behavior of the silica-polyurethane coated PET surface. The changes in morphology and chemical composition of PET surfaces before and after a plasma treatment were analyzed. In order to gain an insight into the formation of a super-amphiphilic PET surface and optimize the conditions under which super-amphiphilicity can be realized, we used a hemi-wicking action as a theoretical model and experimentally verified it through determining the critical angle. We also proposed a guide for designing a nano-sphere patterned PDMS surface which can generate super-wetting properties after a plasma treatment.

  12. Influence of heat treatment on bond strength and corrosion resistance of sol-gel derived bioglass-ceramic coatings on magnesium alloy.

    PubMed

    Shen, Sibo; Cai, Shu; Xu, Guohua; Zhao, Huan; Niu, Shuxin; Zhang, Ruiyue

    2015-05-01

    In this study, bioglass-ceramic coatings were prepared on magnesium alloy substrates through sol-gel dip-coating route followed by heat treatment at the temperature range of 350-500°C. Structure evolution, bond strength and corrosion resistance of samples were studied. It was shown that increasing heat treatment temperature resulted in denser coating structure as well as increased interfacial residual stress. A failure mode transition from cohesive to adhesive combined with a maximum on the measured bond strength together suggested that heat treatment enhanced the cohesion strength of coating on the one hand, while deteriorated the adhesion strength of coating/substrate on the other, thus leading to the highest bond strength of 27.0MPa for the sample heat-treated at 450°C. This sample also exhibited the best corrosion resistance. Electrochemical tests revealed that relative dense coating matrix and good interfacial adhesion can effectively retard the penetration of simulated body fluid through the coating, thus providing excellent protection for the underlying magnesium alloy.

  13. Effects of pulsed light treatments and pectin edible coatings on the quality of fresh-cut apples: a hurdle technology approach.

    PubMed

    Moreira, María R; Álvarez, María V; Martín-Belloso, Olga; Soliva-Fortuny, Robert

    2017-01-01

    Pulsed light (PL) treatments stand as an alternative for the shelf-life extension of fresh-cut products. The antimicrobial effects of PL are well known; however, its influence on quality attributes needs to be assessed. This study was aimed at evaluating the application of PL treatments in combination with pectin-based edible coatings enriched with dietary fiber for the preservation of fresh-cut apples. Dipping of fresh-cut apples in ascorbic acid/calcium chloride solution prior to pectin coating and PL treatments was effective to minimize browning and softening of apple surfaces. Incorporation of fiber in the pectin coating did not cause any change in microbial loads and sensory acceptability of apple cubes. Pectin-coated PL-treated apple pieces exhibited significantly higher antioxidant activity values than fresh and PL control samples. At the end of storage, the combination of both treatments resulted in an almost 2 log CFU g(-1) reduction of microbial counts. Sensory attribute scores did not fall below the rejection limit throughout 14 days, although the presence of off-odors limited the acceptability of the pectin-coated samples. The results demonstrate that PL treatments applied to pectin-coated fresh-cut apples may be used to maintain quality attributes, thus conferring prebiotic potential and extending the shelf-life of the product. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Livestock Air Treatment Using PVA-Coated Powdered Activated Carbon Biofilter

    USDA-ARS?s Scientific Manuscript database

    Ideal biofilter media provide surface for attachment of microorganisms responsible for removing air-born contaminants while facilitating passage of air. This study evaluated the efficacy of polyvinyl alcohol (PVA)-coated powdered activated carbon particles as a biofiltration medium. This material e...

  15. Livestock air treatment using PVA-coated powdered activated carbon biofilter

    USDA-ARS?s Scientific Manuscript database

    The efficacy of polyvinyl alcohol (PVA) biofilters was studied using bench-scale biofilters and air from aerobically-treated swine manure. The PVA-coated powdered activated carbon particles showed excellent properties as a biofiltration medium: water holding capacity of 1.39 g H2O/g-dry PVA; wet por...

  16. Surface treatments and coatings to maintain fresh cut mango quality in storage

    USDA-ARS?s Scientific Manuscript database

    Edible coatings prevent moisture loss and may decrease gas exchange, thereby retaining moisture and flavor of fresh-cut fruit. Previous experiments showed that carboxymethylcellulose (CMC) with added maltodextrin maintained visual quality of stored mango slices also treated with calcium ascorbate an...

  17. Surface treatments and coatings to maintain fresh-cut mango quality in storage

    USDA-ARS?s Scientific Manuscript database

    Edible coatings may improve quality of fresh cut fruit by preventing moisture loss and decreasing gas exchange in storage. This study evaluated the effect of an antioxidant dip made of calcium ascorbate, citric acid and N-acetyl-L-cysteine, followed or not with carboxymethylcellulose (CMC) or carrag...

  18. Enhancing Florida strawberry shelf life using peroxiacetic acid pre-harvest treatments and postharvest edible coatings

    USDA-ARS?s Scientific Manuscript database

    Strawberry is an important fruit crop in Florida. Yearly losses can be attributed to pre- and postharvest decay caused by Botrytis cinerea, and postharvest decay due primarily to Rhizopus stolonifer. Postharvest applications of edible coatings and sanitizers were tested. Among them, a medium-dens...

  19. Effect of silica coating and silane surface treatment on the bond strength of soft denture liner to denture base material

    PubMed Central

    ATSÜ, Saadet; KESKİN, Yasemin

    2013-01-01

    Objective This study investigated the effects of different surface treatments on the tensile bond strength of an autopolymerizing silicone denture liner to a denture base material after thermocycling. Material and Methods Fifty rectangular heat-polymerized acrylic resin (QC-20) specimens consisting of a set of 2 acrylic blocks were used in the tensile test. Specimens were divided into 5 test groups (n=10) according to the bonding surface treatment as follows: Group A, adhesive treatment (Ufi Gel P adhesive) (control); Group S, sandblasting using 50-µm Al2O3; Group SCSIL, silica coating using 30-µm Al2O3 modified by silica and silanized with silane agent (CoJet System); Group SCA, silica coating and adhesive application; Group SCSILA, silica coating, silane and adhesive treatment. The 2 PMMA blocks were placed into molds and the soft lining materials (Ufi Gel P) were packed into the space and polymerized. All specimens were thermocycled (5,000 cycles) before the tensile test. Bond strength data were analyzed using 1-way ANOVA and Duncan tests. Fracture surfaces were observed by scanning electron microscopy. X-ray photoelectron spectrometer (XPS) and Fourier Transform Infrared spectrometer (FTIR) analysis were used for the chemical analysis and a profilometer was used for the roughness of the sample surfaces. Results The highest bond strength test value was observed for Group A (1.35±0.13); the lowest value was for Group S (0.28±0.07) and Group SCSIL (0.34±0.03). Mixed and cohesive type failures were seen in Group A, SCA and SCSILA. Group S and SCSIL showed the least silicone integrations and the roughest surfaces. Conclusion Sandblasting, silica coating and silane surface treatments of the denture base resin did not increase the bond strength of the silicone based soft liner. However, in this study, the chemical analysis and surface profilometer provided interesting insights about the bonding mechanism between the denture base resin and silicone soft liner

  20. Effect of thermal treatments on sputtered silver nanocluster/silica composite coatings on soda-lime glasses: ionic exchange and antibacterial activity

    NASA Astrophysics Data System (ADS)

    Ferraris, M.; Ferraris, S.; Miola, M.; Perero, S.; Balagna, C.; Vernè, E.; Gautier, G.; Manfredotti, Ch.; Battiato, A.; Vittone, E.; Speranza, G.; Bogdanovic, I.

    2012-12-01

    Silver nanocluster/silica composite coatings were deposited on both soda-lime and silica glasses by radio frequency (RF) co-sputtering. The effect of thermal treatments on the microstructure in the range of 150-450 °C were examined by UV-visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Time of Flight-Elastic Recoil Detection Analysis. Sodium/silver ionic exchange was evidenced for coatings sputtered on soda-lime substrates after heating at 450 °C; presence of silver ions and/or silver nanoclusters, nanocluster size and their position inside the sputtered layers will be discussed for as-deposited and heated coatings on both substrates. The antibacterial activity of all coatings was determined against Staphylococcus aureus and Candida albicans by disk diffusion method and colonies forming units count; in agreement with microstructural results, the antibacterial activity present on all coatings was slightly reduced after heating at 450 °C. All coatings have been submitted to humidity plus UV ageing and sterilization by autoclave, gamma ray and ethylene oxide gas. Tape resistance (ASTM D3359-97) tests have been done on each coating before and after ageing and sterilizations, revealing a good adhesion on soda-lime substrates, except for those aged in humidity plus UV and sterilized by autoclave. Scratch tests and nanoindentation tests have been done on each coating, as-deposited and after heating at 450 °C. The coating hardness was improved by heating only when coatings were deposited on silica. The heating of coatings deposited on soda-lime substrates gave opposite effect on their hardness.

  1. Water treatment residual (WTR)-coated wood mulch for alleviation of toxic metals and phosphorus from polluted urban stormwater runoff.

    PubMed

    Soleimanifar, Hanieh; Deng, Yang; Wu, Laying; Sarkar, Dibyendu

    2016-07-01

    Aluminum-based water treatment residual (WTR)-coated wood mulches were synthesized and tested for removal of heavy metals and phosphorus (P) in synthetic urban stormwater. WTRs are an industrial waste produced from coagulation in water treatment facilities, primarily composed of amorphous aluminum or iron hydroxides. Batch tests showed that the composite filter media could effectively adsorb 97% lead (Pb), 76% zinc (Zn), 81% copper (Cu) and 97% P from the synthetic stormwater (Pb = 100 μg/L, Zn = 800 μg/L, Cu = 100 μg/L, P = 2.30 mg/L, and pH = 7.0) within 120 min, due to the presence of aluminum hydroxides as an active adsorbent. The adsorption was a 2(nd)-order reaction with respect toward each pollutant. Column tests demonstrated that the WTR-coated mulches considerably alleviated the select pollutants under a continuous-flow condition over the entire filtration period. The effluent Pb, Zn, Cu, and P varied at 0.5-8.9%, 33.4-46.7%, 45.8-55.8%, and 6.4-51.9% of their respective initial concentrations with the increasing bed volume from 0 to 50. Synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) tests indicated that leached contaminants were all below the U.S. criteria, suggesting that the release of undesired chemicals under rainfall or landfilling conditions is not a concern during application. This study demonstrates that the WTR-coated mulches are a new, low-cost, and effective filter media for urban stormwater treatment. Equally important, this study provides a sustainable approach to beneficially reuse an industrial waste for environmental pollution control.

  2. Localization of fluconazole in oral cavity by preferential coating of buccoadhesive tablet for treatment of oral thrush

    PubMed Central

    Pathak, Kamla; Sharma, Vijay; Akhtar, Nida; Rastogi, Pragya

    2016-01-01

    Background: The present research work was aimed at localization of fluconazole in the oral cavity by preferential coating of buccoadhesive tablet for the treatment of oral thrush. Materials and Methods: In order to achieve the aim, buccoadhesive tablets were optimized using 32 full factorial design to study the influence of varying content of chitosan and carbopol 934P (input variables) on the responses. Results: Perturbation plots revealed high sensitivity of the input variables to ex vivo mucoadhesion force and percent cumulative drug release (CDR) whereas the ex vivo mucoadhesion time was less sensitive to the input variables. Based on the highest desirability factor of 0.693 the formulation F9 was identified as the optimized formulation and was preferentially coated with ethyl cellulose (3% w/v) on one tablet face to get F9C. In reference to F9, F9C showed superior mucoadhesive features (P < 0.05) but the % CDR was comparable (f2 = 50.80). The preferential coating (F9C, Jss = 0.812 μg/cm2/h) limited the permeation of fluconazole across goat buccal mucosa by almost half the value of F9 (Jss = 1.34 μg/cm2/h) that could serve as an advantage in establishing high local concentration of drug in the oral cavity, thereby facilitating faster attainment of minimum inhibitory concentration. Scanning electron microscopy and histological analysis established nonirritant potential. The developed formulation was stable and demonstrated antifungal activity against Candida albicans. Conclusion: Thus it can be concluded that preferentially coated buccoadhesive tablets of fluconazole might be considered as a precise approach to localize the drug delivery in oral cavity. PMID:27051630

  3. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study.

    PubMed

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO4 and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na2HAsO4) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles.

  4. Outcomes of Treatment Targeting Syntax Production in People with Broca's-Type Aphasia: Evidence from Psycholinguistic Assessment Tasks and Everyday Conversation

    ERIC Educational Resources Information Center

    Carragher, Marcella; Sage, Karen; Conroy, Paul

    2015-01-01

    Background: Capturing evidence of the effects of therapy within everyday communication is the holy grail of aphasia treatment design and evaluation. Whilst impaired sentence production is a predominant symptom of Broca's-type aphasia, the effects of sentence production therapy on everyday conversation have not been investigated. Given the…

  5. Outcomes of Treatment Targeting Syntax Production in People with Broca's-Type Aphasia: Evidence from Psycholinguistic Assessment Tasks and Everyday Conversation

    ERIC Educational Resources Information Center

    Carragher, Marcella; Sage, Karen; Conroy, Paul

    2015-01-01

    Background: Capturing evidence of the effects of therapy within everyday communication is the holy grail of aphasia treatment design and evaluation. Whilst impaired sentence production is a predominant symptom of Broca's-type aphasia, the effects of sentence production therapy on everyday conversation have not been investigated. Given the…

  6. [The effect of entecavir treatment on HBV-specific immunity in patient with chronic hepatitis B and its relationship to HBeAg sero-conversion].

    PubMed

    Li, Jian-xiang

    2008-04-01

    To investigate the effect of Entecavir treatment on HBV-specific immunity in patient with chronic hepatitis B and its relationship to HBeAg sero-conversion. Serum aminotransferase (ALT), HBV DNA and HBeAg were monitored before the after entecavir treatment. At the same time point, HBV-specific T cell proliferation was determined by [3H] T-dR incorporation assay, while HBV-specific IFN-alpha secretion was measured by ELISA. The level of HBV DNA and ALT was significantly decreased after entecavir treatment. Same is the titer of HBeAg. In addition, HBeAg sero-conversion was observed in some of them, in whom the HBV-specific T cell proliferation and IFN-alpha production were significantly increased. Entecavir treatment resulted in increased HBV-specific immunity along with the inhibition of HBV replication.

  7. Antibacterial and physical effects of modified chitosan based-coating containing nanoemulsion of mandarin essential oil and three non-thermal treatments against Listeria innocua in green beans.

    PubMed

    Severino, Renato; Vu, Khanh Dang; Donsì, Francesco; Salmieri, Stephane; Ferrari, Giovanna; Lacroix, Monique

    2014-11-17

    The antimicrobial activity against Listeria innocua of three different combined non-thermal treatments, along with the impact on color and texture on green bean samples, was evaluated. In this study a bioactive coating formulation based on modified chitosan containing 0.05% nanoemulsion of mandarin essential oil was tested in combination with γ-irradiation, UV-C and ozonated water treatments, and the results in terms of antimicrobial activity, color and texture changes, were evaluated during 14 days storage. The combined coating and γ-irradiation treatment gave promising results, showing 3.3 log CFU/g initial microbial reduction, and exhibiting a strong synergistic antimicrobial effect. The treatment based on UV-C and coating formulation allowed a 3 log CFU/g reduction of initial L. innocua population on samples, showing a good residual antimicrobial activity and preventing loss of firmness and color changes during storage. The combined treatment of coating and ozonated water did not show any synergistic or additive antimicrobial effect, but they showed an impact on firmness and color. In conclusion UV-C and γ-irradiation treatments, in combination with the bioactive coating, represent an effective approach to control the growth of L. innocua on vegetable foods.

  8. The efficacy of multiple-dose methotrexate treatment for unruptured tubal ectopic pregnancy and conversion rate to surgery: a study on 294 cases.

    PubMed

    Balci, Osman; Ozdemir, Suna; Mahmoud, Alaa S; Acar, Ali; Colakoglu, Mehmet C

    2010-05-01

    In this prospective study 294 patients diagnosed with ectopic pregnancy (EP) were treated with multiple-dose methotrexate (MTX) to determine the conversion rate to surgery. We concluded that multiple-dose MTX treatment had a low success rate, and the success rate was not related to initial b-hCG value; it was more related to the size of gestational mass before treatment.

  9. Atomic Oxygen Treatment for Non-Contact Removal of Organic Protective Coatings from Painting Surfaces

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Banks, Bruce A.; Cales, Michael

    1994-01-01

    Current techniques for removal of varnish (lacquer) and other organic protective coatings from paintings involve contact with the surface. This contact can remove pigment, or alter the shape and location of paint on the canvas surface. A thermal energy atomic oxygen plasma, developed to simulate the space environment in low Earth orbit, easily removes these organic materials. Uniform removal of organic protective coatings from the surfaces of paintings is accomplished through chemical reaction. Atomic oxygen will not react with oxides so that most paint pigments will not be affected by the reaction. For paintings containing organic pigments, the exposure can be carefully timed so that the removal stops just short of the pigment. Color samples of Alizarin Crimson, Sap Green, and Zinc White coated with Damar lacquer were exposed to atomic oxygen. The lacquer was easily removed from all of the samples. Additionally, no noticeable change in appearance was observed after the lacquer was reapplied. The same observations were made on a painted canvas test sample obtained from the Cleveland Museum of Art. Scanning electron microscope photographs showed a slight microscopic texturing of the vehicle after exposure. However, there was no removal or disturbance of the paint pigment on the surface. It appears that noncontact cleaning using atomic oxygen may provide a viable alternative to other cleaning techniques. It is especially attractive in cases where the organic protective surface cannot be acceptably or safely removed by conventional techniques.

  10. Nanocrystalline structure of the surface layer of plasma-sprayed hydroxyapatite coatings obtained upon preliminary induction heat treatment of metal base

    NASA Astrophysics Data System (ADS)

    Fomin, A. A.; Steinhauer, A. B.; Lyasnikov, V. N.; Wenig, S. B.; Zakharevich, A. M.

    2012-05-01

    Biocompatible nanocrystalline hydroxyapatite (HA) coatings for intrabone titanium implants have been obtained by plasma spraying. The HA coatings have an average grain size within 10-30 nm and are characterized by improved characteristics of morphological heterogeneity that is acquired due to the induction heat treatment (IHT) of substrates prior to plasma spray deposition. Based on the data of scanning electron microscopy with computer-aided processing of images, it is established that the average grain size depends on the IHT temperature.

  11. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental Study

    SciTech Connect

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-09-15

    In situ arsenic removal from groundwater by an iron coating method has great potential to be a cost effective and simple groundwater remediation technique, especially in rural and remote areas where groundwater is used as the main source of drinking water. The in situ arsenic removal technique was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions., Its effectiveness was then evaluated in an actual high-arsenic groundwater environment. The mechanism of arsenic removal by the iron coating was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, an electron microprobe, and Fourier transformation infrared spectroscopy. A 4-step alternative cycle aquifer iron coating method was developed. A continuous injection of 5 mmol/L FeSO4 and 2.5 mmol/L NaClO for 96 hours can create a uniform coating of crystalline goethite on the surface of quartz sand in the columns without causing clogging. At a flow rate of 0.45 cm/min of the injection reagents (vi), the time for arsenic (as Na2HAsO4) to pass through the iron-coated quartz sand column was approximately 35 hours, which was much longer than that for tracer fluorescein sodium (approximately 2 hours). The retardation factor of arsenic was 23, and its adsorption capacity was 0.11 mol As per mol Fe, leading to an excellent arsenic removal. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As (V) and Fe (II) reagents. When the arsenic content in the groundwater was 233 μg/L, the aqueous phase arsenic was completely removed with an arsenic adsorption of 0.05 mol As per mol Fe. Arsenic fixation resulted from a process of adsorption/co-precipitation, in which arsenic and iron likely formed the arsenic-bearing iron mineral phases with poor crystallinity by way of bidentate binuclear complexes. Thus, the high arsenic removal efficiency of the technique likely resulted from the

  12. Dependence of scale thickness on the breaking behavior of the initial oxide on plasma spray bond coat surface during vacuum pre-treatment

    NASA Astrophysics Data System (ADS)

    Zhang, Bang-Yan; Meng, Guo-Hui; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

    2017-03-01

    The thermally grown oxide (TGO) on the thermal spray bond coat surface was one of the most important factors which would influence the lifetime of thermal barrier coatings (TBCs). Pre-diffusion treatment (high temperature vacuum treatment) plays an important role in the growth of the TGO. Results show that the initial thin oxide scale, formed during deposition process, on the as-sprayed bond coating surface has broken and shrunk to discontinuous oxide particles through the elements diffusion during the pre-diffusion. Two kinds of bond coats with different initial oxide scale thicknesses were subjected to the same pre-diffusion. The two pre-diffused bond coats show different results of the average distance between the individual oxide particles. In this study, a three dimensional model with thermal grooving theory was developed to explore the essential condition for the scale breaking and explain the differences of these results. This research can provide reference for the preparation optimization and pre-treatment optimization of bond coat towards high performance TBCs.

  13. A new cementless total hip arthroplasty with bioactive titanium porous-coating by alkaline and heat treatment: average 4.8-year results.

    PubMed

    Kawanabe, Keiichi; Ise, Kentaro; Goto, Koji; Akiyama, Haruhiko; Nakamura, Takashi; Kaneuji, Ayumi; Sugimori, Tanzo; Matsumoto, Tadami

    2009-07-01

    A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.

  14. Cytotoxic characteristics of biodegradable EW10X04 Mg alloy after Nd coating and subsequent heat treatment.

    PubMed

    Katarivas Levy, Galit; Ventura, Yvonne; Goldman, Jeremy; Vago, Razi; Aghion, Eli

    2016-05-01

    Porous Mg scaffolds are considered as potential bone growth promoting materials. Unfortunately, the high rate of biocorrosion inherent to Mg alloys may cause a premature loss of mechanical strength, excessive evolution of hydrogen gas, and a rapidly shifting surface topography, all of which may hinder the ability of native cells to attach and grow on the implant surface. Here we investigated the cell cytotoxicity effects during corrosion of a novel magnesium alloy, EW10X04 (Mg-1.2%Nd-0.5%Y-0.5%Zr-0.4%Ca), following diffusion coating (DC) and heat treatment to reduce the corrosion rate. Cells were exposed either to corrosion products or to the corroding scaffold surface, in vitro. The microstructure characterization of the scaffold surface was carried out by scanning electron microscopy (SEM) equipped with a Noran energy dispersive spectrometer (EDS). Phase analyses were obtained by X-ray diffraction (XRD). We found that cell viability, growth, and adhesion were all improved when cultured on the EW10X04+DC surface or under corrosion product extracts due to lower corrosion rates relative to the EW10X04 control samples. It is therefore believed that the tested alloy after Nd coating and heat treatment may introduce a good balance between its biodegradation characteristics and cytotoxic effects towards cells.

  15. The Influence of Plasma Nitriding Pre-Treatment on Tribological Properties of TiN Coatings Deposited by PACVD

    NASA Astrophysics Data System (ADS)

    Mahdipoor, M. S.; Mahboubi, F.; Ahangarani, Sh.; Raoufi, M.; Elmkhah, H.

    2012-06-01

    The aim of this study is to investigate the effect of plasma nitriding pre-treatment (PN) on mechanical and tribological behavior of TiN coatings produced by plasma-assisted chemical vapor deposition (PACVD). The heat treatment of quench and temper was carried out on hot work AISI H11 (DIN 1.2343) steel samples. A group of samples were plasma nitrided at 500 °C for 4 h in an atmosphere containing 25 vol.% nitrogen and 75 vol.% hydrogen. Then TiN layer was deposited on all of samples at 520 °C temperature, 8 kHz frequency, and 33% duty cycle. The microstructural, mechanical, and tribological properties of the coatings were investigated using SEM, WDS, AFM, microhardness tester, and pin-on-disc wear test. The load of wear test was 10 N and the samples were worn against different pins, ball-bearing steel (DIN 1.3505), and cemented tungsten carbide (WC-Co). The results indicate that the difference of hardness between the samples with PN-TiNlayer and those samples with only TiN layer without PN was 450 HV and the former samples showed a significant amount of wear resistance in comparison to the latter ones.

  16. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    PubMed

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-08-14

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.

  17. The interplay of plasma treatment and gold coating and ultra-high molecular weight polyethylene: On the cytocompatibility.

    PubMed

    Novotná, Zdenka; Rimpelová, Silvie; Juřík, Petr; Veselý, Martin; Kolská, Zdenka; Hubáček, Tomáš; Ruml, Tomáš; Švorčík, Václav

    2017-02-01

    We have investigated the application of Ar plasma for creation of nanostructured ultra high molecular weight polyethylene (PE) surface in order to enhance adhesion of mouse embryonic fibroblasts (L929). The aim of this study was to investigate the effect of the interface between plasma-treated and gold-coated PE on adhesion and spreading of cells. The surface properties of pristine samples and its modified counterparts were studied by different experimental techniques (gravimetry, goniometry and X-ray photoelectron spectroscopy (XPS), electrokinetic analysis), which were used for characterization of treated and sputtered layers, polarity and surface chemical structure, respectively. Further, atomic force microscopy (AFM) was employed to study the surface morphology and roughness. Biological responses of cells seeded on PE samples were evaluated in terms of cell adhesion, spreading, morphology and proliferation. Detailed cell morphology and intercellular connections were followed by scanning electron microscopy (SEM). As it was expected the thickness of a deposited gold film was an increasing function of the sputtering time. Despite the fact that plasma treatment proceeded in inert plasma, oxidized degradation products were formed on the PE surface which would contribute to increased hydrophilicity (wettability) of the plasma treated polymer. The XPS method showed a decrease in carbon concentration with increasing plasma treatment. Cell adhesion measured on the interface between plasma treated and gold coated PE was inversely proportional to the thickness of a gold layer on a sample. Copyright © 2016. Published by Elsevier B.V.

  18. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment

    PubMed Central

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P.; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEONLA-BSA, which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEONLA-BSA particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEONLA-BSA changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment. PMID:26287178

  19. Prospects for Adapting Current ASTM Wear and Erosion Tests for Bulk Materials to Thin Films, Coatings, and Surface Treatments

    SciTech Connect

    Blau, Peter Julian

    2007-01-01

    Most of ASTM Committee G2's erosion, wear, and friction test standards were developed for use with bulk materials, yet there is a growing need to evaluate the tribological behavior of films, coatings, and surface treatments (FCSTs), some that affect layers only tens of nanometers to a few micrometers thick. Tribotesting standards for bulk materials can sometimes be modified for use on FCSTs, but the conditions and methods developed for bulk materials may sometimes be too severe or inapplicable. An internet search and literature review indicated that a number of G2 Committee standards are currently being used for FCSTs. Of these, ASTM G99 and G65 seem to be the most popular. When attempting to apply an existing wear standard for bulk materials to FCSTs, two key issues must be addressed: (1) whether changes are needed in the magnitudes of the applied conditions, and (2) whether more precise methods are needed to measure the magnitude of surface damage. Straightforward calculations underscore the limitations for wear measurement of thin layers when evaluated using block-on-ring and pin-on-disk tests. Finally, suggestions are given for modifying selected ASTM G2 standards to enable their use on films, coatings, and surface treatments.

  20. Effect of post-deposition treatment on energy conversion efficiency of nanostructured CdS/Cu{sub 2}S thin films

    SciTech Connect

    Taur, Vidya S.; Joshi, Rajesh A.; Sharma, Ramphal

    2013-02-05

    In the present manuscript we report about synthesis of nanostructured CdS/Cu{sub 2}S thin films by economically viable soft chemical route and effect of post deposition treatments such as annealing in air and swift heavy ion irradiation on solar energy conversion efficiency of the heterojunction device. These as grown, annealed and irradiated thin films are characterized for structural, morphological, optical and I-V properties. X-ray diffraction pattern (XRD) represents structural as well as crystallite modifications, atomic force microscopy (AFM) shows improvement in surface appearance of the materials. The solar energy conversion efficiency calculated from I-V exhibited increase in conversion efficiency i. e. 0.09, 0.24 and 0.48 % for as grown, annealed and SHI irradiated thin films.

  1. In vitro studies of heparin-coated magnetic nanoparticles for potential use in the treatment of neointimal hyperplasia

    NASA Astrophysics Data System (ADS)

    Hargett, Andrew

    Purpose: Though recent decades have developed a myriad of treatments in response to atherosclerosis, prevalence remains high and complications, especially restenosis, may occur. Restenosis following stents is often caused by excessive vascular smooth muscle cell (VSMCS) migration and proliferation into the intima, known as neointimal hyperplasia. The shear number of angioplasty and stent procedures throughout the world makes this a major concern of all endovascular surgery. Our lab has proposed the pairing of heparin and magnetic nanoparticles for targeted drug delivery to the stent location. Utilizing the high surface area of nanoparticles, we hope to deliver higher heparin dosing to inhibit VSMC proliferation without systemic effects. This study evaluates synthesis of these particles as well as preliminary in vitro controls on relevant cell lines found within the vasculature system. Materials and Methods: Heparin-coated iron oxide nanoparticles were synthesized and characterized according to size (TEM), hydrodynamic diameter (DLS), zeta potential, iron concentration, and heparin loading (DMMB assay). Assays were then performed using these particles as experimental conditions on VSMCs, Endothelial Cells (PECs), and Fibroblasts (3T3s) for determination of cell uptake (Prussian Blue, TEM), effects on proliferation (MTS assay), cytotoxicity (Live/Dead assay), and phenotype changes (immunofluorescent staining). Experimental conditions were assessed against control nanoparticles without heparin and raw heparin in solution for dosage effects. Results: Particles were successfully synthesized, loaded with heparin, and characterized to validate each step of synthesis. Proliferation and cytotoxicity cell assays determined heparin-coated nanoparticles to be more potent in effects at lower concentrations of heparin when compared to raw heparin in solution. Immunostaining of VSMCs demonstrated a relatively higher tendency towards nonproliferative phenotypes following

  2. Irreversible conversion of the physical state of herpes simplex virus preceding inactivation by thermal or antibody treatment

    SciTech Connect

    Yanagi, K.

    1981-05-01

    The buoyant density characteristics of infectious particles of herpes simplex virus types 1 and 2 were studied by centrifugation in sucrose and cesium chloride density gradients with a high resolution and satisfactory infectivity recovery. It was shown that two populations of infectious virions differing in buoyant density coexisted, the difference being slight but definite. The ratio of heavy (H) to light (L) viral particles varied depending upon the solute used, the strains of virus, and the cell origin. Circumstances favoring degradation of viral infectivity tended to increase the H portion. Incubation at 37 degrees C largely converted L to H, and heating at 45 degrees C converted all virions to H without infectivity. The L to H conversion was irreversible, and no populations intermediate between L and H were clearly observed. Inactivation by UV light irradiation did not affect the density pattern. That H was not an artefact due to penetration of solutes, osmotic pressure, viral aggregation, or loss of the envelope was shown experimentally. A difference in the outer shape of particles between negatively stained L and H populations was demonstrated by electron microscopy. Both cell-released and cell-bound herpes simplex virus particles gave essentially the same result with respect to the above characteristics. The effect of limiting dilutions of antiserum was similar to that of mild thermal treatment, in that denser virions increased parallel to a decrease in less dense virions. Sensitization with early immunoglobulin G, composed mainly of complement-requiring neutralizing antibody, caused the density transition, and subsequent addition of complement resulted in a further increase in the buoyant density of the sensitized virions.

  3. A Conversation on Data Mining Strategies in LC-MS Untargeted Metabolomics: Pre-Processing and Pre-Treatment Steps

    PubMed Central

    Tugizimana, Fidele; Steenkamp, Paul A.; Piater, Lizelle A.; Dubery, Ian A.

    2016-01-01

    Untargeted metabolomic studies generate information-rich, high-dimensional, and complex datasets that remain challenging to handle and fully exploit. Despite the remarkable progress in the development of tools and algorithms, the “exhaustive” extraction of information from these metabolomic datasets is still a non-trivial undertaking. A conversation on data mining strategies for a maximal information extraction from metabolomic data is needed. Using a liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomic dataset, this study explored the influence of collection parameters in the data pre-processing step, scaling and data transformation on the statistical models generated, and feature selection, thereafter. Data obtained in positive mode generated from a LC-MS-based untargeted metabolomic study (sorghum plants responding dynamically to infection by a fungal pathogen) were used. Raw data were pre-processed with MarkerLynxTM software (Waters Corporation, Manchester, UK). Here, two parameters were varied: the intensity threshold (50–100 counts) and the mass tolerance (0.005–0.01 Da). After the pre-processing, the datasets were imported into SIMCA (Umetrics, Umea, Sweden) for more data cleaning and statistical modeling. In addition, different scaling (unit variance, Pareto, etc.) and data transformation (log and power) methods were explored. The results showed that the pre-processing parameters (or algorithms) influence the output dataset with regard to the number of defined features. Furthermore, the study demonstrates that the pre-treatment of data prior to statistical modeling affects the subspace approximation outcome: e.g., the amount of variation in X-data that the model can explain and predict. The pre-processing and pre-treatment steps subsequently influence the number of statistically significant extracted/selected features (variables). Thus, as informed by the results, to maximize the value of untargeted metabolomic data

  4. A Conversation on Data Mining Strategies in LC-MS Untargeted Metabolomics: Pre-Processing and Pre-Treatment Steps.

    PubMed

    Tugizimana, Fidele; Steenkamp, Paul A; Piater, Lizelle A; Dubery, Ian A

    2016-11-03

    Untargeted metabolomic studies generate information-rich, high-dimensional, and complex datasets that remain challenging to handle and fully exploit. Despite the remarkable progress in the development of tools and algorithms, the "exhaustive" extraction of information from these metabolomic datasets is still a non-trivial undertaking. A conversation on data mining strategies for a maximal information extraction from metabolomic data is needed. Using a liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomic dataset, this study explored the influence of collection parameters in the data pre-processing step, scaling and data transformation on the statistical models generated, and feature selection, thereafter. Data obtained in positive mode generated from a LC-MS-based untargeted metabolomic study (sorghum plants responding dynamically to infection by a fungal pathogen) were used. Raw data were pre-processed with MarkerLynx(TM) software (Waters Corporation, Manchester, UK). Here, two parameters were varied: the intensity threshold (50-100 counts) and the mass tolerance (0.005-0.01 Da). After the pre-processing, the datasets were imported into SIMCA (Umetrics, Umea, Sweden) for more data cleaning and statistical modeling. In addition, different scaling (unit variance, Pareto, etc.) and data transformation (log and power) methods were explored. The results showed that the pre-processing parameters (or algorithms) influence the output dataset with regard to the number of defined features. Furthermore, the study demonstrates that the pre-treatment of data prior to statistical modeling affects the subspace approximation outcome: e.g., the amount of variation in X-data that the model can explain and predict. The pre-processing and pre-treatment steps subsequently influence the number of statistically significant extracted/selected features (variables). Thus, as informed by the results, to maximize the value of untargeted metabolomic data, understanding

  5. Biomaterial Co-Cr-Mo Alloys Nano Coating Calcium Phosphate Orthopedic Treatment

    NASA Astrophysics Data System (ADS)

    Palaniappan, N.; Inwati, Gajendra Kumar; Singh, Man

    2014-08-01

    The modem study a thermal martensitic transformation of biomedical Co-Cr-Mo alloys and ultimately offers large elongation to failure while maintaining high strength. In the future study, structural evolution and dislocation slip as an elementary process in the martensitic transformation in Co-Cr-Mo alloys were investigated to reveal the origin of their enhanced phase stability due to nitrogen addition and coating of calcium phosphate specimens with and without nitrogen addition were prepared. The N-doped alloys had a single-phase matrix, whereas the N-free alloys had a duplex microstructure. Irrespective of the nitrogen content, dislocations frequently dissociated into Shockley partial dislocations with stacking faults. The Nano range coating of calcium phosphate function as obstacles to the glide of partial dislocations and consequently significantly affect the kinetics of the martensitic transformation. As a result, the formation of marten site plays a crucial role in plastic deformation and wear behavior, the developed nanostructures modification associated with nitrogen addition must be a promising strategy for highly durable orthopedic implants.

  6. Effect of cathode vibration and heat treatment on electromagnetic properties of flake-shaped diatomite coated with Ni-Fe alloy by electroplating

    NASA Astrophysics Data System (ADS)

    Lan, Mingming; Li, Huiqin; Huang, Weihua; Xu, Guangyin; Li, Yan

    2015-03-01

    In this paper, flake-shaped diatomite particles were used as forming templates for the fabrication of the ferromagnetic functional fillers by way of electroplating Ni-Fe alloy method. The effects of cathode vibration frequency on the content of Ni-Fe alloy in the coating and the surface morphologies of the coatings were evaluated. The electromagnetic properties of the coated diatomite particles before and after heat treatment were also investigated in detail. The results show that the core-shell flake-shaped diatomite particles with high content of Ni-Fe alloy and good surface qualities of the coatings can be obtained by adjusting cathode vibration frequency. The coated diatomite particles with heat treatment filled paraffin wax composites exhibit a superior microwave absorbing and electromagnetic properties compared to the non-heat treated samples. Additionally, the peaks of reflection loss are found to be able to shift to lower frequency by the heat treatment process, which indicates the heat treatment can adjust microwave absorbing frequency band.

  7. Laser Surface Treatment of Hydro and Thermal Power Plant Components and Their Coatings: A Review and Recent Findings

    NASA Astrophysics Data System (ADS)

    Mann, B. S.

    2015-11-01

    High-power diode laser (HPDL) surface modification of hydro and thermal power plant components is of the utmost importance to minimize their damages occurring due to cavitation erosion, water droplet erosion, and particle erosion (CE, WDE, and PE). Special emphasis is given on the HPDL surface treatment of martensitic and precipitate-hardened stainless steels, Ti6Al4V alloy, plasma ion nitro-carburized layers, high pressure high velocity oxy-fuel and twin-wire arc sprayed coatings. WDE test results of all these materials and coatings in `untreated' and `HPDL- treated at 1550 °C' conditions, up to 8.55 million cycles, are already available. Their WDE testing was further continued up to 10.43 million cycles. The X20Cr13 and X10CrNiMoV1222, the most common martensitic stainless steels used in hydro and thermal power plants, were HPDL surface treated at higher temperature (1650 °C) and their WDE test results were also obtained up to 10.43 million cycles. It is observed that the increased HPDL surface temperature from 1550 to 1650 °C has resulted in significant improvement in their WDE resistances because of increased martensitic (ά) phase at higher temperature. After conducting long-range WDE tests, the correlation of CE, WDE, and PE resistances of these materials and protective coatings with their mechanical properties such as fracture toughness and microhardness product, ultimate resilience, modified resilience, and ultimate modified resilience has been reviewed and discussed. One of the edges of a 500 MW low pressure steam turbine moving blade (X10CrNiMoV1222 stainless steel) was HPDL surface treated at 1550 °C and its radii of curvatures and deflections were measured. These were compared with the data available earlier from a flat rectangular sample of similar composition and identical HPDL surface temperature.

  8. Thermal Treatment Temperature and Time Dependence of Contact Angle of Water on Fluorinated Polystyrene as Hydrophobic Film Coating

    NASA Astrophysics Data System (ADS)

    Tolentino, M. S.; Carpena, J. F.; Javier, R. M.; Aquino, R. R.

    2017-06-01

    The study focuses on the synthesis of fluorinated polystyrene (F-PS) as a hydrophobic film coating and on the investigation of the consequent effects of thermal treatment time and treatment temperature on its contact angle. The fluorinated polystyrene is synthesized via Friedel-Crafts acylation of the benzoic rings by electrophilic substitution of trifluoroacetic anhydride in the presence of AlCl3 in an environment of dichloromethane as the aprotic solvent with a reaction temperature of 36°C. The reaction yielded fluorinated polystyrene characterized by a solid brown substance. FT-IR analysis of the substance had shown band peaks at 1150 cm-1, a wavenumber indicating the presence of fluorine in the synthesized material, which lowers its surface energy. SEM images of the F-PS show nucleation sites giving rise to hierarchical structures on the surface of the material due to the action of fluorination. The contact angle of fluorinated polystyrene, upon application of thermal treatment, increased to as much as 29.26% when compared to the unmodified polystyrene manifesting a preferentially more hydrophobic behavior. It was also found that the contact angle increases linearly with treatment temperature while statistical analysis shows that thermal treatment time has no significant effect on the hydrophobicity of the F- PS.

  9. Micro-oxidation treatment to improve bonding strength of Sr and Na co-substituted hydroxyapatite coatings for carbon/carbon composites

    NASA Astrophysics Data System (ADS)

    Zhang, Leilei; Li, Hejun; Li, Kezhi; Zhang, Yulei; Liu, Shoujie; Guo, Qian; Li, Shaoxian

    2016-08-01

    To improve the bonding strength of Sr and Na co-substituted hydroxyapatite (SNH) coatings for carbon/carbon composites, carbon/carbon composites are surface modified by micro-oxidation treatment. The micro-oxidation treatment could generate large number of pores containing oxygenic functional groups on the surface of carbon/carbon composites. SNH is nucleated on the inwall of the pores and form a flaky shape coating with 10-50 nm in thickness and 200-900 nm in width. The bonding strength between SNH coating and carbon/carbon composites increases from 4.27 ± 0.26 MPa to 10.57 ± 0.38 MPa after the micro-oxidation treatment. The promotion of bonding strength is mainly attributed to the pinning effect caused by the pores and chemical bonding generated by the oxygenic functional groups.

  10. Comparison between alkali heat treatment and sprayed hydroxyapatite coating on thermally-sprayed rough Ti surface in rabbit model: Effects on bone-bonding ability and osteoconductivity.

    PubMed

    Kawai, Toshiyuki; Takemoto, Mitsuru; Fujibayashi, Shunsuke; Tanaka, Masashi; Akiyama, Haruhiko; Nakamura, Takashi; Matsuda, Shuichi

    2015-07-01

    In this study, we investigated the effect of different surface treatments (hydroxyapatite (HA) coating, alkali heat treatment, and no treatment) on the ability of bone to bond to a rough arc-sprayed Ti metal surface, using rabbit models. The bone-to-implant contacts for untreated, HA-coated, and alkali heat-treated implants were 21.2%, 72.1%, and 33.8% at 4 weeks, 21.8%, 70.9%, and 30.0% at 8 weeks, and 16.3%, 70.2%, and 29.9% at 16 weeks, respectively (n = 8). HA -coated implants showed significantly higher bone-to-implant contacts than the untreated and alkali heat-treated implants at all the time point, whereas alkali heat-treated implants showed significantly higher bone-to-implant contacts than untreated implants at 4 and 16 weeks. The failure loads in a mechanical test for untreated, HA coated, alkali heat-treated plates were 65.4 N, 70.7 N, and 90.8 N at 4 weeks, 76.1 N, 64.7 N, and 104.8 N at 8 weeks and 88.7 N, 92.6 N, and 118.5 N at 16 weeks, respectively (n = 8). The alkali heat-treated plates showed significantly higher failure loads than HA-coated plates at 8 and 16 weeks. The difference between HA-coated plates and untreated plates were not statistically significant at any time point. Thus HA coating, although it enables high bone-to-implant contact, may not enhance the bone-bonding properties of thermally-sprayed rough Ti metal surfaces. In contrast, alkali heat treatment can be successfully applied to thermally-sprayed Ti metal to enhance both bone-to-implant contact and bone-bonding strength. © 2014 Wiley Periodicals, Inc.

  11. Drug-Coated Balloon Versus Standard Percutaneous Transluminal Angioplasty for the Treatment of Superficial Femoral and Popliteal Peripheral Artery Disease

    PubMed Central

    Tepe, Gunnar; Schneider, Peter; Brodmann, Marianne; Krishnan, Prakash; Micari, Antonio; Metzger, Christopher; Scheinert, Dierk; Zeller, Thomas; Cohen, David J.; Snead, David B.; Alexander, Beaux; Landini, Mario; Jaff, Michael R.

    2015-01-01

    Background— Drug-coated balloons (DCBs) have shown promise in improving the outcomes for patients with peripheral artery disease. We compared a paclitaxel-coated balloon with percutaneous transluminal angioplasty (PTA) for the treatment of symptomatic superficial femoral and popliteal artery disease. Methods and Results— The IN.PACT SFA Trial is a prospective, multicenter, single-blinded, randomized trial in which 331 patients with intermittent claudication or ischemic rest pain attributable to superficial femoral and popliteal peripheral artery disease were randomly assigned in a 2:1 ratio to treatment with DCB or PTA. The primary efficacy end point was primary patency, defined as freedom from restenosis or clinically driven target lesion revascularization at 12 months. Baseline characteristics were similar between the 2 groups. Mean lesion length and the percentage of total occlusions for the DCB and PTA arms were 8.94±4.89 and 8.81±5.12 cm (P=0.82) and 25.8% and 19.5% (P=0.22), respectively. DCB resulted in higher primary patency versus PTA (82.2% versus 52.4%; P<0.001). The rate of clinically driven target lesion revascularization was 2.4% in the DCB arm in comparison with 20.6% in the PTA arm (P<0.001). There was a low rate of vessel thrombosis in both arms (1.4% after DCB and 3.7% after PTA [P=0.10]). There were no device- or procedure-related deaths and no major amputations. Conclusions— In this prospective, multicenter, randomized trial, DCB was superior to PTA and had a favorable safety profile for the treatment of patients with symptomatic femoropopliteal peripheral artery disease. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique Identifiers: NCT01175850 and NCT01566461. PMID:25472980

  12. Protection of Reinforced Concrete Structures of Waste Water Treatment Reservoirs with Stainless Steel Coating Using Arc Thermal Spraying Technique in Acidified Water

    PubMed Central

    Lee, Han-Seung; Park, Jin-Ho; Singh, Jitendra Kumar; Ismail, Mohamed A.

    2016-01-01

    Waste water treatment reservoirs are contaminated with many hazardous chemicals and acids. Reservoirs typically comprise concrete and reinforcement steel bars, and the main elements responsible for their deterioration are hazardous chemicals, acids, and ozone. Currently, a variety of techniques are being used to protect reservoirs from exposure to these elements. The most widely used techniques are stainless steel plating and polymeric coating. In this study, a technique known as arc thermal spraying was used. It is a more convenient and economical method for protecting both concrete and reinforcement steel bar from deterioration in waste water treatment reservoirs. In this study, 316L stainless steel coating was applied to a concrete surface, and different electrochemical experiments were performed to evaluate the performance of coatings in different acidic pH solutions. The coating generated from the arc thermal spraying process significantly protected the concrete surface from corrosion in acidic pH solutions, owing to the formation of a double layer capacitance—a mixture of Cr3+ enriched with Cr2O3 and Cr-hydroxide in inner and Fe3+ oxide on the outer layer of the coating. The formation of this passive film is defective owing to the non-homogeneous 316L stainless steel coating surface. In the pH 5 solution, the growth of a passive film is adequate due to the presence of un-dissociated water molecules in the aqueous sulfuric acid solution. The coated surface is sealed with alkyl epoxide, which acts as a barrier against the penetration of acidic solutions. This coating exhibits higher impedance values among the three studied acidic pH solutions. PMID:28773875

  13. Protection of Reinforced Concrete Structures of Waste Water Treatment Reservoirs with Stainless Steel Coating Using Arc Thermal Spraying Technique in Acidified Water.

    PubMed

    Lee, Han-Seung; Park, Jin-Ho; Singh, Jitendra Kumar; Ismail, Mohamed A

    2016-09-03

    Waste water treatment reservoirs are contaminated with many hazardous chemicals and acids. Reservoirs typically comprise concrete and reinforcement steel bars, and the main elements responsible for their deterioration are hazardous chemicals, acids, and ozone. Currently, a variety of techniques are being used to protect reservoirs from exposure to these elements. The most widely used techniques are stainless steel plating and polymeric coating. In this study, a technique known as arc thermal spraying was used. It is a more convenient and economical method for protecting both concrete and reinforcement steel bar from deterioration in waste water treatment reservoirs. In this study, 316L stainless steel coating was applied to a concrete surface, and different electrochemical experiments were performed to evaluate the performance of coatings in different acidic pH solutions. The coating generated from the arc thermal spraying process significantly protected the concrete surface from corrosion in acidic pH solutions, owing to the formation of a double layer capacitance-a mixture of Cr(3+) enriched with Cr₂O₃ and Cr-hydroxide in inner and Fe(3+) oxide on the outer layer of the coating. The formation of this passive film is defective owing to the non-homogeneous 316L stainless steel coating surface. In the pH 5 solution, the growth of a passive film is adequate due to the presence of un-dissociated water molecules in the aqueous sulfuric acid solution. The coated surface is sealed with alkyl epoxide, which acts as a barrier against the penetration of acidic solutions. This coating exhibits higher impedance values among the three studied acidic pH solutions.

  14. Effects of high temperature treatment on microstructure and mechanical properties of laser-clad NiCrBSi/WC coatings on titanium alloy substrate

    SciTech Connect

    Li, Guang Jie; Li, Jun Luo, Xing

    2014-12-15

    Laser-clad composite coatings on the Ti6Al4V substrate were heat-treated at 700, 800, and 900 °C for 1 h. The effects of post-heat treatment on the microstructure, microhardness, and fracture toughness of the coatings were investigated by scanning electron microscopy, X-ray diffractometry, energy dispersive spectroscopy, and optical microscopy. The wear resistance of the coatings was evaluated under dry reciprocating sliding friction at room temperature. The coatings mainly comprised some coarse gray blocky (W,Ti)C particles accompanied by the fine white WC particles, a large number of black TiC cellular/dendrites, and the matrix composed of NiTi and Ni{sub 3}Ti; some unknown rich Ni- and Ti-rich particles with sizes ranging from 10 nm to 50 nm were precipitated and uniformly distributed in the Ni{sub 3}Ti phase to form a thin granular layer after heat treatment at 700 °C. The granular layer spread from the edge toward the center of the Ni{sub 3}Ti phase with increasing temperature. A large number of fine equiaxed Cr{sub 23}C{sub 6} particles with 0.2–0.5 μm sizes were observed around the edges of the NiTi supersaturated solid solution when the temperature was further increased to 900 °C. The microhardness and fracture toughness of the coatings were improved with increased temperature due to the dispersion-strengthening effect of the precipitates. Dominant wear mechanisms for all the coatings included abrasive and delamination wear. The post-heat treatment not only reduced wear volume and friction coefficient, but also decreased cracking susceptibility during sliding friction. Comparatively speaking, the heat-treated coating at 900 °C presented the most excellent wear resistance. - Highlights: • TiC + WC reinforced intermetallic compound matrix composite coatings were produced. • The formation mechanism of the reinforcements was analyzed. • Two precipitates were generated at elevated temperature. • Cracking susceptibility and microhardness of the

  15. A novel and facile synthesis of porous SiO2-coated ultrasmall Se particles as a drug delivery nanoplatform for efficient synergistic treatment of cancer cells

    NASA Astrophysics Data System (ADS)

    Liu, Xijian; Deng, Guoying; Wang, Yeying; Wang, Qian; Gao, Zhifang; Sun, Yangang; Zhang, Wenlong; Lu, Jie; Hu, Junqing

    2016-04-01

    A novel and facile synthetic route has been developed to fabricate porous SiO2-coated ultrasmall Se particles (Se@SiO2 nanospheres) as a drug delivery nanoplatform which combines Se quantum dots and doxorubicin (DOX) for efficient synergistic treatment of cancer cells.A novel and facile synthetic route has been developed to fabricate porous SiO2-coated ultrasmall Se particles (Se@SiO2 nanospheres) as a drug delivery nanoplatform which combines Se quantum dots and doxorubicin (DOX) for efficient synergistic treatment of cancer cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02298g

  16. The Role of Health Care Provider Goals, Plans, and Physician Orders for Life-Sustaining Treatment (POLST) in Preparing for Conversations About End-of-Life Care.

    PubMed

    Russell, Jessica

    2016-09-01

    The Physician Orders for Life-Sustaining Treatment (POLST) is a planning tool representative of an emerging paradigm aimed at facilitating elicitation of patient end-of-life care preferences. This study assessed the impact of the POLST document on provider goals and plans for conversations about end-of-life care treatment options. A 2 (POLST: experimental, control) × 3 (topic of possible patient misunderstanding: cardiopulmonary resuscitation, medical intervention, artificially administered nutrition) experimental design was used to assess goals, plan complexity, and strategies for plan alterations by medical professionals. Findings suggested that the POLST had little impact on plan complexity or reaction time with initial plans. However, preliminary evidence suggested that the utility of the POLST surfaced with provider responses to patient misunderstanding, in which differences in conditions were identified. Significant differences in goals reported as most important in driving conversational engagement emerged. Implications for findings are discussed.

  17. Effect of Nano-Si3N4 Additives and Plasma Treatment on the Dry Sliding Wear Behavior of Plasma Sprayed Al2O3-8YSZ Ceramic Coatings

    NASA Astrophysics Data System (ADS)

    Gou, Junfeng; Zhang, Jian; Zhang, Qiwen; Wang, You; Wang, Chaohui

    2017-04-01

    In this paper, the effect of nano-Si3N4 additives and plasma treatment on the wear behavior of Al2O3-8YSZ ceramic coatings was studied. Nano-Al2O3, nano-8YSZ (8 wt.% Y2O3-stabilized ZrO2) and nano-Si3N4 powders were used as raw materials to fabricate four types of sprayable feedstocks. Plasma treatment was used to improve the properties of the feedstocks. The surface morphologies of the ceramic coatings were observed. The mechanical properties of the ceramic coatings were measured. The dry sliding wear behavior of the Al2O3-8YSZ coatings with and without Si3N4 additives was studied. Nano-Si3N4 additives and plasma treatment can improve the morphologies of the coatings by prohibiting the initiation of micro-cracks and reducing the unmelted particles. The hardness and bonding strength of AZSP (Al2O3-18 wt.% 8YSZ-10 wt.% Si3N4-plasma treatment) coating increased by 79.2 and 44% compared to those of AZ (Al2O3-20 wt.% 8YSZ) coating. The porosity of AZSP coating decreased by 85.4% compared to that of AZ coating. The wear test results showed that the addition of nano-Si3N4 and plasma treatment could improve the wear resistance of Al2O3-8YSZ coatings.

  18. Effect of Nano-Si3N4 Additives and Plasma Treatment on the Dry Sliding Wear Behavior of Plasma Sprayed Al2O3-8YSZ Ceramic Coatings

    NASA Astrophysics Data System (ADS)

    Gou, Junfeng; Zhang, Jian; Zhang, Qiwen; Wang, You; Wang, Chaohui

    2017-02-01

    In this paper, the effect of nano-Si3N4 additives and plasma treatment on the wear behavior of Al2O3-8YSZ ceramic coatings was studied. Nano-Al2O3, nano-8YSZ (8 wt.% Y2O3-stabilized ZrO2) and nano-Si3N4 powders were used as raw materials to fabricate four types of sprayable feedstocks. Plasma treatment was used to improve the properties of the feedstocks. The surface morphologies of the ceramic coatings were observed. The mechanical properties of the ceramic coatings were measured. The dry sliding wear behavior of the Al2O3-8YSZ coatings with and without Si3N4 additives was studied. Nano-Si3N4 additives and plasma treatment can improve the morphologies of the coatings by prohibiting the initiation of micro-cracks and reducing the unmelted particles. The hardness and bonding strength of AZSP (Al2O3-18 wt.% 8YSZ-10 wt.% Si3N4-plasma treatment) coating increased by 79.2 and 44% compared to those of AZ (Al2O3-20 wt.% 8YSZ) coating. The porosity of AZSP coating decreased by 85.4% compared to that of AZ coating. The wear test results showed that the addition of nano-Si3N4 and plasma treatment could improve the wear resistance of Al2O3-8YSZ coatings.

  19. Environmentally friendly electroless plating for Ag/TiO2-coated core-shell magnetic particles using ultrasonic treatment.

    PubMed

    Kim, Soo-Dong; Choe, Won-Gyun; Jeong, Jong-Ryul

    2013-11-01

    In this work, high-reflectance brilliant white color magnetic microspheres comprising a Fe/TiO2/Ag core-shell structure with a continuous, uniform compact silver layer were successfully fabricated by TiO2-assisted electroless plating in a simple and eco-friendly method. The coating procedure for TiO2 and Ag involved a sol-gel reaction and electroless plating with ultrasound treatment. The electroless plating step was carried out in an eco-friendly manner in a single process without environmentally toxic additives. The TiO2 layer was used as a modification layer between the Fe microspheres and the silver layer to improve adhesion. A continuous and compact silver layer could be formed with a high degree of morphological control by introducing ultrasonication and adjusting the ammonium hydroxide concentration.

  20. Contentious Conversations

    ERIC Educational Resources Information Center

    Zuidema, Leah A.

    2011-01-01

    The idea of joining a conversation through reading and writing is not new; in his 1941 book "The Philosophy of Literary Form: Studies in Symbolic Action," Kenneth Burke suggests that the acts of reading and writing are like entering a parlor where others are already conversing. The author explores the place of professional debate within NCTE and…

  1. Contentious Conversations

    ERIC Educational Resources Information Center

    Zuidema, Leah A.

    2011-01-01

    The idea of joining a conversation through reading and writing is not new; in his 1941 book "The Philosophy of Literary Form: Studies in Symbolic Action," Kenneth Burke suggests that the acts of reading and writing are like entering a parlor where others are already conversing. The author explores the place of professional debate within NCTE and…

  2. Developing surface pre-treatments for electrophoretic deposition of biofunctional chitosan-bioactive glass coatings on a WE43 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Höhlinger, Michael; Heise, Svenja; Wagener, Victoria; Boccaccini, Aldo R.; Virtanen, Sannakaisa

    2017-05-01

    The use of Mg alloys as biodegradable implants requires optimizing the surface performance. A high number of surface modification and coating approaches have been previously explored, for instance to make magnesium and its alloys more corrosion resistant. The current study focuses on developing surface pre-treatments as a corrosion protection and primer for further surface modifications by electrophoretic deposition (EPD) of bioadaptive chitosan-bioactive glass coatings. For this, different surface treatments were tested on a WE43 Mg alloy. These treatments include immersion in Dulbecco's Modified Eagle's Medium (DMEM), a calcium phosphate treatment, immersion in hydrofluoric acid, and a hydrothermal procedure in NaOH. The resulting coatings were analyzed in view of the surface morphology and composition by SEM/EDX, as well as in view of their short-term corrosion protection ability by electrochemistry. Finally, the suitability of the different pre-treatments as an interfacial protection layer for subsequent EPD of a chitosan/bioactive glass-coating was explored.

  3. Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis

    PubMed Central

    SILVA, Emilia Adriane; TRINDADE, Flávia Zardo; RESKALLA, Hélcio Nagib José Feres; de QUEIROZ, José Renato Cavalcanti

    2013-01-01

    Objective This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. Material and Methods Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). Results The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. Conclusion Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are a more effective strategy. PMID:24037072

  4. Effects of Spray Parameters and Post-spray Heat Treatment on Microstructure and Mechanical Properties of Warm-Sprayed Ti-6Al-4V Coatings

    NASA Astrophysics Data System (ADS)

    Molak, R. M.; Araki, H.; Watanabe, M.; Katanoda, H.; Ohno, N.; Kuroda, S.

    2016-12-01

    Warm spray is a novel thermal spray technique that allows the formation of dense and relatively pure Ti-6Al-4V coatings due to its capability to control the temperature of the propellant gas by diluting the combustion flame with an inert gas such as nitrogen. Recently, its combustion pressure has been increased from 1 to 4 MPa aiming to further increase particle velocity to over 1000 m/s. Two series of coatings with combustion pressure of 1 and 4 MPa and various nitrogen flow rates were prepared in this study. Effects of combustion pressure and nitrogen flow rate on the microstructure and mechanical properties of the Ti-6Al-4V coatings were systematically studied. Miniature tensile specimens with a total length of about 9 mm were used for static tensile tests. It was found that the spray parameters affect both the porosity and oxygen content of the coatings significantly and had remarkable effects on their mechanical properties. High level of porosity in the Ti-6Al-4V coatings reduced the effective cross-sectional area of the mini-specimens and caused a drop in their tensile strength and Young's modulus. Subsequent heat treatments were found effective in significantly recovering the mechanical properties of the as-sprayed coatings.

  5. Effects of Spray Parameters and Post-spray Heat Treatment on Microstructure and Mechanical Properties of Warm-Sprayed Ti-6Al-4V Coatings

    NASA Astrophysics Data System (ADS)

    Molak, R. M.; Araki, H.; Watanabe, M.; Katanoda, H.; Ohno, N.; Kuroda, S.

    2017-04-01

    Warm spray is a novel thermal spray technique that allows the formation of dense and relatively pure Ti-6Al-4V coatings due to its capability to control the temperature of the propellant gas by diluting the combustion flame with an inert gas such as nitrogen. Recently, its combustion pressure has been increased from 1 to 4 MPa aiming to further increase particle velocity to over 1000 m/s. Two series of coatings with combustion pressure of 1 and 4 MPa and various nitrogen flow rates were prepared in this study. Effects of combustion pressure and nitrogen flow rate on the microstructure and mechanical properties of the Ti-6Al-4V coatings were systematically studied. Miniature tensile specimens with a total length of about 9 mm were used for static tensile tests. It was found that the spray parameters affect both the porosity and oxygen content of the coatings significantly and had remarkable effects on their mechanical properties. High level of porosity in the Ti-6Al-4V coatings reduced the effective cross-sectional area of the mini-specimens and caused a drop in their tensile strength and Young's modulus. Subsequent heat treatments were found effective in significantly recovering the mechanical properties of the as-sprayed coatings.

  6. Development of hydrophobicity and selective separation of hazardous chlorinated plastics by mild heat treatment after PAC coating and froth flotation.

    PubMed

    Thanh Truc, Nguyen Thi; Lee, Chi-Hyeon; Lee, Byeong-Kyu; Mallampati, Srinivasa Reddy

    2017-01-05

    Polyvinyl chloride (PVC) containing chlorine can release highly toxic materials and persistent organic pollutants if improperly disposed of. The combined technique of powder activated carbon (PAC) coating and mild heat treatment has been found to selectively change the surface hydrophobicity of PVC, enhancing its wettability and thereby promoting its separation from heavy plastic mixtures included polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS) and acrylonitrile butadiene styrene (ABS) by means of froth flotation. The combined treatments helped to rearrange the surface components and make PVC more hydrophobic, while the remaining plastics became more hydrophilic. After the treatments at 150°C for 80s the contact angle of the PVC was greatly increased from 90.5 to 97.9°. The SEM and AFM reveal that the surface morphology and roughness changes on the PVC surface. XPS and FT-IR results further confirmed an increase of hydrophobic functional groups on the PVC surface. At the optimized froth flotation and subsequent mixing at 150rpm, 100% of PVC was recovered from the remaining plastic mixture with 93.8% purity. The combined technique can provide a simple and effective method for the selective separation of PVC from heavy plastics mixtures to facilitate easy industrial recycling.

  7. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment

    PubMed Central

    Liu, HaoRan; Raza, Aikifa; Aili, Abulimiti; Lu, JinYou; AlGhaferi, Amal; Zhang, TieJun

    2016-01-01

    Nanostructured materials with desired wettability and optical property can play an important role in reducing the energy consumption of oily water treatment technologies. For effective oily water treatment, membrane materials with high strength, sunlight-sensitive anti-fouling, relative low fabrication cost, and controllable wettability are being explored. In the proposed oily water treatment approach, nanostructured TiO2-coated copper (TNS-Cu) meshes are used. These TNS-Cu meshes exhibit robust superhydrophilicity and underwater oleophobicity (high oil intrusion pressure) as well as excellent chemical and thermal stability (≈250 °C). They have demonstrated high separation efficiency (oil residue in the filtrate ≤21.3 ppm), remarkable filtration flux (≥400 kL h−1 m−2), and sunlight-sensitive anti-fouling properties. Both our theoretical analysis and experimental characterization have confirmed the enhanced light absorption property of TNS-Cu meshes in the visible region (40% of the solar spectrum) and consequently strong anti-fouling capability upon direct solar light illumination. With these features, the proposed approach promises great potential in treating produced oily wastewater from industry and daily life. PMID:27160349

  8. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment

    NASA Astrophysics Data System (ADS)

    Liu, Haoran; Raza, Aikifa; Aili, Abulimiti; Lu, Jinyou; Alghaferi, Amal; Zhang, Tiejun

    2016-05-01

    Nanostructured materials with desired wettability and optical property can play an important role in reducing the energy consumption of oily water treatment technologies. For effective oily water treatment, membrane materials with high strength, sunlight-sensitive anti-fouling, relative low fabrication cost, and controllable wettability are being explored. In the proposed oily water treatment approach, nanostructured TiO2-coated copper (TNS-Cu) meshes are used. These TNS-Cu meshes exhibit robust superhydrophilicity and underwater oleophobicity (high oil intrusion pressure) as well as excellent chemical and thermal stability (≈250 °C). They have demonstrated high separation efficiency (oil residue in the filtrate ≤21.3 ppm), remarkable filtration flux (≥400 kL h‑1 m‑2), and sunlight-sensitive anti-fouling properties. Both our theoretical analysis and experimental characterization have confirmed the enhanced light absorption property of TNS-Cu meshes in the visible region (40% of the solar spectrum) and consequently strong anti-fouling capability upon direct solar light illumination. With these features, the proposed approach promises great potential in treating produced oily wastewater from industry and daily life.

  9. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment.

    PubMed

    Liu, HaoRan; Raza, Aikifa; Aili, Abulimiti; Lu, JinYou; AlGhaferi, Amal; Zhang, TieJun

    2016-05-10

    Nanostructured materials with desired wettability and optical property can play an important role in reducing the energy consumption of oily water treatment technologies. For effective oily water treatment, membrane materials with high strength, sunlight-sensitive anti-fouling, relative low fabrication cost, and controllable wettability are being explored. In the proposed oily water treatment approach, nanostructured TiO2-coated copper (TNS-Cu) meshes are used. These TNS-Cu meshes exhibit robust superhydrophilicity and underwater oleophobicity (high oil intrusion pressure) as well as excellent chemical and thermal stability (≈250 °C). They have demonstrated high separation efficiency (oil residue in the filtrate ≤21.3 ppm), remarkable filtration flux (≥400 kL h(-1 )m(-2)), and sunlight-sensitive anti-fouling properties. Both our theoretical analysis and experimental characterization have confirmed the enhanced light absorption property of TNS-Cu meshes in the visible region (40% of the solar spectrum) and consequently strong anti-fouling capability upon direct solar light illumination. With these features, the proposed approach promises great potential in treating produced oily wastewater from industry and daily life.

  10. Gold nanolayer and nanocluster coatings induced by heat treatment and evaporation technique.

    PubMed

    Schaub, Anna; Slepička, Petr; Kašpárková, Irena; Malinský, Petr; Macková, Anna; Svorčík, Václav

    2013-05-22

    The paper is focused on the preparation and surface characterization of gold coatings and nanostructures deposited on glass substrate. Different approaches for the layer preparation were applied. The gold was deposited on the glass with (i) room temperature, (ii) glass heated to 300°C, and (iii) the room temperature-deposited glass which was consequently annealed to 300°C. The sheet resistance and concentration of free carriers were determined by the van der Pauw method. Surface morphology was characterized using an atomic force microscopy. The optical properties of gold nanostructures were measured by UV-vis spectroscopy. The evaporation technique combined with simultaneous heating of the glass leads to change of the sheet resistance, surface roughness, and optical properties of gold nanostructures. The electrically continuous layers are formed for significantly higher thickness (18 nm), if the substrate is heated during evaporation process. The annealing process influences both the structure and optical properties of gold nanostructures. The elevated temperature of glass during evaporation amplifies the peak of plasmon resonance in the structures, the surface morphology being significantly altered.

  11. Gold nanolayer and nanocluster coatings induced by heat treatment and evaporation technique

    NASA Astrophysics Data System (ADS)

    Schaub, Anna; Slepička, Petr; Kašpárková, Irena; Malinský, Petr; Macková, Anna; Švorčík, Václav

    2013-05-01

    The paper is focused on the preparation and surface characterization of gold coatings and nanostructures deposited on glass substrate. Different approaches for the layer preparation were applied. The gold was deposited on the glass with (i) room temperature, (ii) glass heated to 300°C, and (iii) the room temperature-deposited glass which was consequently annealed to 300°C. The sheet resistance and concentration of free carriers were determined by the van der Pauw method. Surface morphology was characterized using an atomic force microscopy. The optical properties of gold nanostructures were measured by UV-vis spectroscopy. The evaporation technique combined with simultaneous heating of the glass leads to change of the sheet resistance, surface roughness, and optical properties of gold nanostructures. The electrically continuous layers are formed for significantly higher thickness (18 nm), if the substrate is heated during evaporation process. The annealing process influences both the structure and optical properties of gold nanostructures. The elevated temperature of glass during evaporation amplifies the peak of plasmon resonance in the structures, the surface morphology being significantly altered.

  12. Arsenic removal by iron oxide coated sponge: treatment and waste management.

    PubMed

    Nguyen, Tien Vinh; Rahman, Abdur; Vigneswaran, Saravanamuthu; Ngo, Huu Hao; Kandasamy, Jaya; Nguyen, Duc Tho; Do, Tuan Anh; Nguyen, Trung Kien

    2009-01-01

    One of the problems in drinking water that raises concern over the world is that millions of people still have to use arsenic-contaminated water. There is a worldwide need to develop appropriate technologies to remove arsenic from water for household and community water supply systems. In this study, a new material namely iron oxide coated sponge (IOCSp) was developed and used to remove arsenic (As) from contaminated groundwater in Vietnam. The results indicated that IOCSp has a high capacity in removing both As (V) and As (III). The adsorption capacity of IOCSp was up to 4.6 mg As/g IOCSp, showing better than many other materials. It was observed from a pilot study that a small quantity of IOCSp (180 g) could reduce As concentration of 480 microg/L in 1.5 m3 of contaminated natural water to below 40 microg/L. In addition, an exhausted IOCSp, containing a large amount of arsenic (up to 0.42 wt %) could safely be disposed through the solidification/stabilization with cement. Addition of fly ash also reduced the amount of arsenic in the leachate.

  13. Improvement of the Adhesion Strength of MoSi2-ZrB2 Coating by Optimizing Particle Spraying and Subsequent Heat Treatment

    NASA Astrophysics Data System (ADS)

    Lu, Wang; Qian-gang, Fu; Ning-kun, Liu; Jia, Sun

    2016-10-01

    A MoSi2-ZrB2 coating was prepared on SiC-coated C/C composites by supersonic plasma spraying, and the effects of particle diameter and subsequent heat treatment in argon at different temperatures on the adhesion strength were studied. The results show that the MoSi2-ZrB2 coating sprayed with an average powder diameter of 29.2 μm could melt thoroughly and form a dense structure without micro-pore, which results in a relatively good adhesion strength of 11.4 MPa compared with 9.2 and 8.6 MPa of the coatings sprayed with the powder diameter of 58.2 and 35.5 μm. The coating presents a decreasing porosity from 2.2 to 1.5% and an increasing adhesion strength from 11.6 to 16.9 MPa after heat treatment at 800 °C, which is mainly caused by slight sintering of SiO2 and B2O3

  14. Evaluating the role of soluble aluminum in manganese removal via MnOx(s)-coated filtration media in drinking water treatment.

    PubMed

    Jones, A; Knocke, W R

    2017-03-15

    The Mn oxide (MnOx(s)) surfaces of water treatment filtration media are known to aid in the capture of dissolved Mn species, but the discovery of significant deposits of Al within these coatings (Tobiason et al., 2008) raised certain questions about the possible role of Al in soluble Mn removal and the formation of the MnOx(s) surface on the media. This phenomenon was addressed by conducting a series of bench-scale column studies that involved the application of solutions containing varying amounts of soluble Al and Mn to MnOx(s)-coated media. The experimental results confirmed that soluble Al was removed in significant amounts by adsorption onto the MnOx(s) media surface. The deposition of soluble Al onto the media surface did not have any significant effect on its ability to remove soluble Mn. Likewise, the relative amounts of Al incorporated into the media coating suggested that uptake of soluble Al alone cannot fully explain the levels of Al often found in real-world, MnOx(s)-coated filter media; instead, the incorporation of particulate forms of Al (routinely found in water treatment plant situations) must contribute to the formation of the MnOx(s) coatings on these media.

  15. Effects of Al Content and Addition of Third Element on Fabrication of Ti-Al Intermetallic Coatings by Heat Treatment of Warm-Sprayed Precursors

    NASA Astrophysics Data System (ADS)

    Sienkiewicz, J.; Kuroda, S.; Minagawa, K.; Murakami, H.; Araki, H.; Kurzydłowski, K. J.

    2015-06-01

    Four powder mixtures of titanium and aluminum with 50:50, 40:60, 30:70, and 20:80 atomic ratios were used as feedstock for Warm Spray process to produce composite coatings. A two-stage heat treatment at 600 and 1000 °C was applied to the deposits in order to obtain titanium aluminide intermetallic phases. The microstructure, chemical, and phase composition of the as-deposited and heat-treated coatings were investigated using SEM, EDS, and XRD. It was found that the Al content affects on the thickness expansion of the heat-treated Ti-Al coatings significantly and also has a major influence on the porosity development, which is caused by the Kirkendall effect. The effects of adding a third element Si and heat treatment with pressure to produce denser Ti-Al intermetallic coating were also examined. The investigated hot-pressed coatings with addition of Si exhibited much denser microstructure and contained Ti-Al intermetallic phases with titanium silicide precipitates.

  16. Synergistic effect of PEG and hydrosol treatments of solution on preparing Al2O3 coating by cathode plasma electrolytic deposition

    NASA Astrophysics Data System (ADS)

    Liu, Chenxu; Zhang, Jin; He, Yedong; Zhang, Shuguang; Wang, Peng; Lian, Yong; Deng, Shunjie

    2017-03-01

    Al2O3 coatings were prepared by cathode plasma electrolytic deposition (CPED) in the solutions containing Al(NO3)3 · 9H2O, polyethylene glycol (PEG) and hydrosol treated at different conditions. It was found that the deposition efficiency of Al2O3 coatings could be improved by adding PEG in Al(NO3)3 solution and hydrosol treatment of the Al(NO3)3 solution respectively, while the deposition efficiency was synergistically enhanced by both together. It was proved that Al2O3 gel was formed in the solution after hydrosol treatment. Therefore, there is a synergistic effect of PEG and Al2O3 gel on preparing Al2O3 coating by CPED. Such synergistic effect can be mainly attributed to the formation of thin gas sheath on the cathode surface under the action of PEG and Al2O3 gel together. Consequently, at 120 V, the over-potential in the gas sheath is decreased, while the over-potential in Al2O3 coating is increased. At the same time, the current density of the cathode is decreased, so a thick Al2O3 coating can be prepared by CPED in an effective way.

  17. The effect of surface treatment on the surface texture and contact angle of electrochemically deposited hydroxyapatite coating and on its interaction with bone-forming cells.

    PubMed

    Eliaz, Noam; Shmueli, Sharon; Shur, Irena; Benayahu, Dafna; Aronov, Daniel; Rosenman, Gil

    2009-10-01

    This work demonstrates the effects of both surface preparation and surface post-treatment by exposure to electron beam on the surface texture, contact angle and the interaction with bone-forming cells of electrochemically deposited hydroxyapatite (HAp) coating. Both the surface texture and the contact angle of the ground titanium substrate changed as a result of either heat treatment following soaking in NaOH solution or soaking in H(2)O(2) solution. Consequently, the shape of the current transients during potentiostatic deposition of HAp changed, and the resulting coatings exhibited different surface textures and contact angles. The developed interfacial area ratio Sdr and the core fluid retention index Sci were found more reliable than the mean roughness R(a) and the root-mean-square roughness Z(rms) in correlating the adhesion of the coating to the metal substrate and the cellular response with surface texture. The NaOH pretreatment provided the highest surface area and induced the highest cell attachment, even though the H(2)O(2) treatment provided the highest hydrophilicity to the metal substrate. Electrodeposition at pH 6 was found preferable compared to electrodeposition at pH 4.2. The ability to modify the cellular response by exposure to unique electron-beam surface treatment was demonstrated. The very high hydrophilicity of the as-deposited HAp coating enhanced its bioactivity.

  18. Selective separation of ABS/PC containing BFRs from ABSs mixture of WEEE by developing hydrophilicity with ZnO coating under microwave treatment.

    PubMed

    Thanh Truc, Nguyen Thi; Lee, Byeong-Kyu

    2017-05-05

    This study reports a simple and facile method to separate plastic wastes of acrylonitrile-butadiene-styrene (ABS) and ABS-based plastics (blends of ABS) in waste electronic and electrical equipment (WEEE) by froth flotation after inducing hydrophilization by ZnO coating under microwave treatment. ABS-based plastics containing brominated flame retardants (BFRs) can release hazardous substances, such as hydrogen bromide and brominated dioxins, during disposal or recycling activities. ABS and ABS-based plastics are typical styrene plastics with similar properties and it is, therefore, difficult to separate them selectively for recycling. We used 2-min microwave treatment to rearrange and change the molecular mobility on the surface of the ZnO-coated ABS with increased hydrophilic surfaces, which eased the selective separation of the ABS/polycarbonate (PC) blend containing BFRs from the remaining plastics. Therefore, the combined ZnO coating and microwave treatments can facilitate the selective separation of ABS/PC blend plastics with a recovery and purity of 100% and 91.7%, respectively, in a short flotation time of 2min. Based on these findings, the combination of ZnO coating-microwave treatment and froth flotation can be applied for the selective separation of ABS-based plastics, leading to improved plastic recycling quality.

  19. Coating of Ultrathin Polymer Films on Carbon Nanotubes by a Plasma Treatment

    DTIC Science & Technology

    2003-01-01

    treatment. HRTEM experiments showed that an extremely thin film of the pyrrole layer (2-7 nm) was uniformly deposited on the surfaces of the nanotubes...treatment. The polyacrylic film will react with metallic ions in water. As a result of the high surface-to-volume ratio of these nanostructured clusters...introduced into the reactor chamber. The operating pressure was adjusted by the mass flow controller. Pyrrole was used as the mo- nomer for plasma

  20. The effect of surface treatments on the adhesion of electrochemically deposited hydroxyapatite coating to titanium and on its interaction with cells and bacteria.

    PubMed

    Eliaz, Noam; Ritman-Hertz, Oshrit; Aronov, Daniel; Weinberg, Evgeny; Shenhar, Yotam; Rosenman, Gil; Weinreb, Miron; Ron, Eliora

    2011-07-01

    The effect of different mechanical and chemical pre-treatments on the adhesion strength of hydroxyapatite (HAp) coating on a commercially pure titanium (CP-Ti) substrate was studied by means of a standard tensile test followed by microscopic and chemical analysis to determine the locus of fracture. In addition, the effects of either these pre-treatments or post-treatment by low-energy electron irradiation, which allowed tuning the wettability of the surface, on both osteoblast progenitor attachment and S. aureus bacteria attachment were investigated. A dedicated program was developed for unambiguous identification and count of stained cells. A single-phase HAp coating was formed by electrodeposition. A series of surface pre-treatments consisted of grinding down to P1000, etching in HNO₃/HF solution, grit blast, soaking in NaOH and subsequent heat treatment provided the highest adhesion strength to the HAp coating. Osteoblast progenitors derived from rats may be attached preferentially to a hydrophilic surface (post-treatment to θ = 30°), while the bacteria seemed to be less attached to hydrophobic surfaces (post-treatment to θ = 105°). However, the results were not statistically different. The bacteria seemed to be less attached to the smoother, uncoated surfaces.

  1. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections

    PubMed Central

    Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

    2016-01-01

    Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

  2. Improved Efficacy of Ciprofloxacin Administered in Polyethylene Glycol-Coated Liposomes for Treatment of Klebsiella pneumoniae Pneumonia in Rats

    PubMed Central

    Bakker-Woudenberg, Irma A. J. M.; ten Kate, Marian T.; Guo, Luke; Working, Peter; Mouton, Johan W.

    2001-01-01

    Animal and clinical data show that high ratios of the area under the concentration-time curve and the peak concentration in blood to the MIC of fluoroquinolones for a given pathogen are associated with a favorable outcome. The present study investigated whether improvement of the therapeutic potential of ciprofloxacin could be achieved by encapsulation in polyethylene glycol (PEG)-coated long-circulating sustained-release liposomes. In a rat model of unilateral Klebsiella pneumoniae pneumonia (MIC = 0.1 μg/ml), antibiotic was administered at 12- or 24-h intervals at twofold-increasing doses. A treatment period of 3 days was started 24 h after inoculation of the left lung, when the bacterial count had increased 1,000-fold and some rats had positive blood cultures. The infection was fatal within 5 days in untreated rats. Administration of ciprofloxacin in the liposomal form resulted in delayed ciprofloxacin clearance and increased and prolonged ciprofloxacin concentrations in blood and tissues. The ED50 (dosage that results in 50% survival) of liposomal ciprofloxacin was 3.3 mg/kg of body weight/day given once daily, and that of free ciprofloxacin was 18.9 mg/kg/day once daily or 5.1 mg/kg/day twice daily. The ED90 of liposomal ciprofloxacin was 15.0 mg/kg/day once daily compared with 36.0 mg/kg/day twice daily for free ciprofloxacin; 90% survival could not be achieved with free ciprofloxacin given once daily. In summary, the therapeutic efficacy of liposomal ciprofloxacin was superior to that of ciprofloxacin in the free form. PEG-coated liposomal ciprofloxacin was well tolerated in relatively high doses, permitting once daily administration with relatively low ciprofloxacin clearance and without compromising therapeutic efficacy. PMID:11302815

  3. Analysis of micromixers and biocidal coatings on water-treatment membranes to minimize biofouling.

    SciTech Connect

    Webb, Stephen W.; James, Darryl L.; Hibbs, Michael R.; Jones, Howland D. T.; Hart, William Eugene; Khalsa, Siri Sahib; Altman, Susan Jeanne; Clem, Paul Gilbert; Elimelech, Menachem; Cornelius, Christopher James; Sanchez, Andres L.; Noek, Rachael M.; Ho, Clifford Kuofei; Kang, Seokatae; Sun, Amy Cha-Tien; Adout, Atar; McGrath, Lucas K.; Cappelle, Malynda A.; Cook, Adam W.

    2009-12-01

    Biofouling, the unwanted growth of biofilms on a surface, of water-treatment membranes negatively impacts in desalination and water treatment. With biofouling there is a decrease in permeate production, degradation of permeate water quality, and an increase in energy expenditure due to increased cross-flow pressure needed. To date, a universal successful and cost-effect method for controlling biofouling has not been implemented. The overall goal of the work described in this report was to use high-performance computing to direct polymer, material, and biological research to create the next generation of water-treatment membranes. Both physical (micromixers - UV-curable epoxy traces printed on the surface of a water-treatment membrane that promote chaotic mixing) and chemical (quaternary ammonium groups) modifications of the membranes for the purpose of increasing resistance to biofouling were evaluated. Creation of low-cost, efficient water-treatment membranes helps assure the availability of fresh water for human use, a growing need in both the U. S. and the world.

  4. Metric Conversion

    Atmospheric Science Data Center

    2013-03-12

    ... 1,000,000 1,000,000 micrometers nano- 1,000,000,000 1,000,000,000 nanometers ... conversions, see the National Institute of Standards and Technology (NIST) Special Publications: NIST Guide to SI Units: ...

  5. Conversation Analysis.

    ERIC Educational Resources Information Center

    Schiffrin, Deborah

    1990-01-01

    Summarizes the current state of research in conversation analysis, referring primarily to six different perspectives that have developed from the philosophy, sociology, anthropology, and linguistics disciplines. These include pragmatics; speech act theory; interactional sociolinguistics; ethnomethodology; ethnography of communication; and…

  6. Improved conversion efficiency in dye-sensitized solar cells based on electrospun Al-doped ZnO nanofiber electrodes prepared by seed layer treatment

    SciTech Connect

    Yun Sining; Lim, Sangwoo

    2011-02-15

    The application of electrospun nanofibers in electronic devices is limited due to their poor adhesion to conductive substrates. To improve this, a seed layer (SD) is introduced on the FTO substrate before the deposition of the electrospun composite nanofibers. This facilitates the release of interfacial tensile stress during calcination and enhances the interfacial adhesion of the AZO nanofiber films with the FTO substrate. Dye-sensitized solar cells (DSSC) based on these AZO nanofiber photoelectrodes have been fabricated and investigated. An energy conversion efficiency ({eta}) of 0.54-0.55% has been obtained under irradiation of AM 1.5 simulated sunlight (100 mW/cm{sup 2}), indicating a massive improvement of {eta} in the AZO nanofiber film DSSCs after SD-treatment of the FTO substrate as compared to those with no treatment. The SD-treatment has been demonstrated to be a simple and facile method to solve the problem of poor adhesion between electrospun nanofibers and the conductive substrate. -- Graphical abstract: The poor adhesion between electrospun nanofibers and substrate is improved by a simple and facile seed layer (SD) treatment. The energy conversion efficiency of AZO nanofiber-based DSSCs has been greatly increased by SD-treatment of the FTO substrate. Display Omitted Research highlights: {yields} A simple and facile method (SD-treatment) has been demonstrated. {yields} The poor adhesion between electrospun nanofibers and substrate is improved by the SD-treatment. {yields} The {eta} of AZO nanofiber-based DSSCs has been greatly improved by SD-treatment of the FTO substrate.

  7. Seed-coat Dormancy in Grevillea linearifolia: Little Change in Permeability to an Apoplastic Tracer after Treatment with Smoke and Heat

    PubMed Central

    Briggs, Candida L.; Morris, E. Charles

    2008-01-01

    Background and Aims Seeds of Grevillea linearifolia germinate following fire, and have seed-coat dormancy broken by smoke and heat shock. Smoke breaks seed coat dormancy in Emmenanthe penduliflora by altering the permeability of the seed coat to an internal germination inhibitor, which subsequently escapes. This model was tested for in G. linearifolia by investigating the permeability of the seed coat to diffusion of high-molecular-weight compounds, and whether this changed after exposure to fire cues. Methods Germination response of the seeds to heat shock, smoke or heat + smoke was tested. Penetration of Lucifer Yellow dye into intact seeds was examined after 24 and 48 h of exposure, and penetration of the dye from the inside of the seed coat outwards was examined after 24 h. Histochemical staining with Nile Red and Acridine Orange was used to locate cuticles, suberin and lignin. Key Results Twenty-three per cent of untreated seeds germinated; heat shock and smoke increased germination additively up to approx. 80 % for both cues combined. Lucifer Yellow did not penetrate fully through the seed coat of untreated seeds, whether diffusing inwards or outwards. Three barriers to diffusion were identified. Treatment with heat or smoke slightly increased penetration of the dye, but did not completely remove the barriers. Suberin was identified in secondary walls of exotestal and mesotestal cells, and was absent from primary cell walls. Movement of Lucifer Yellow occurred through the middle lamella and primary cell wall of suberized cells; movement of the dye was impeded where suberin was absent. Conclusions Fire cues did not significantly decrease barriers to diffusion of high-molecular-weight compounds in the seed coat of Grevillea, and must be breaking dormancy by another mechanism. PMID:18250110

  8. Mesenchymal stem cells and endothelial progenitor cells accelerate intra-aneurysmal tissue organization after treatment with SDF-1α-coated coils.

    PubMed

    Gao, Yuyuan; Lu, Ziming; Chen, Chengwei; Cui, Xubo; Liu, Yaqi; Zheng, Tao; Jiang, Xiaodan; Zeng, Chi; Quan, Daping; Wang, Qiujing

    2016-04-01

    Recurrences of aneurysms remain the major drawback of detachable coils for the endovascular treatment of intracranial aneurysms. The aim of the present study is to develop new modified coils, coating the surface of platinum coils with silk fibroin (SF) consisting of stromal cell-derived factor-1α (SDF-1α), and evaluate its acceleration of organization of cavities and reduction of lumen size in a rat aneurysm model. The morphological characteristics of SDF-1α-coated coils were examined using scanning electron microscopy (SEM). Fifty experimental aneurysms were created and randomly divided into five groups: three groups were embolized with SDF-1α-coated coils (8 mm) and two of these groups need transplantation of mesenchymal stem cells (MSCs) or endothelial progenitor cells (EPCs); one group was embolized with bare coils (8 mm) and another group severed as control. After coil implantation for 14 or 28 days, the coils were harvested and histological analysis was performed. SEM photographs showed that SF/SDF-1α-coated coils have uniform size and a thin film compared with bare coils. In the group treated with SDF-1α-coated coils, tissue organization was accelerated and the proliferation of α-smooth muscle actin positive cells was promoted in the aneurysmal sac. Compared with unmodified coils, on day 28, tissue organization was significantly greater in the group treated with SDF-1α-coated coils and MSC or EPC transplantation. These results suggest that SDF-1α-coated coils with MSC or EPC transplantation may be beneficial in the aneurysm healing and endothelialization at the orifice of embolized aneurysm.

  9. Sand-blasting treatment as a way to improve the adhesion strength of hydroxyapatite coating on titanium implant

    NASA Astrophysics Data System (ADS)

    Grubova, I.; Priamushko, T.; Surmeneva, M.; Korneva, O.; Epple, M.; Prymak, O.; Surmenev, R.

    2017-05-01

    In the current study, the effect of corundum particle sizes (50 and 250-320 μm) used for sand-blasting on the structure, roughness, wettability, mechanical properties, and adhesion of radio frequency magnetron hydroxyapatite coating deposited on treated titanium substrate is studied. Morphology analysis revealed that pretreatment uniformly deforms the surface and induces the formation of pits, which size depends linearly on the grit size. The deposited coatings (Ca/P was in a range of 1.75-1.79) are homogeneous and repeat the relief of the substrate (mean roughness Ra is 1.9±0.1 (250-320 μm) and 0.8±0.1 μm (50 μm)). Texture coefficient calculations revealed the predominant (002) growth texture of hydroxyapatite coatings. The resistance of the coating to plastic deformation and the surface hardening were significantly higher for coatings formed on sand blasted with particle size of 50 μm. Scratch test have shown the significant improvement of wear resistance and lower friction coefficient of coatings for smoother samples. Dynamic contact angle measurements revealed the hydrophilic properties of the hydroxyapatite coating. Thus, sand-blasting of titanium with corundum powder having the size of 50 μm prior to the deposition of RF magnetron coating is recommended for the medical applications intended to improve the bonding between the substrate and coating.

  10. Microstructural analyses and wear behavior of the cemented carbide tools after laser surface treatment and PVD coating

    NASA Astrophysics Data System (ADS)

    Neves, Davi; Diniz, Anselmo Eduardo; Lima, Milton Sérgio Fernandes

    2013-10-01

    Adhesion is one of the most important characteristics of coating on cutting tools. Poor coating adhesion on the tool favors fragmentation and release of hard abrasive particles between the tool and the workpiece. These particles interact with the surfaces of the tool, accelerating its wear and decreasing tool life. One possible solution is the use of laser texturing prior to coating in order to achieve a desired surface topography with enhanced adhesion properties. In the texturing, a high-frequency short-pulse laser changes surface characteristics, generating resolidified material and selective vaporization. This work evaluated the effectiveness of laser texturing in improving the substrate-coating adhesion of PVD coated cemented carbide tools. To this end, the substrates were textured with a Nd:YAG laser, in four different intensities, and then coated with a PVD TiAlN film. To ascertain the effectiveness of laser texturing, Rockwell C indentation and turning experiments were performed on both textured tools and conventional unlasered tools. The PVD coated laser-textured tool showed better performance in the indentation and turning tests than the standard tools. A comparative evaluation of tool wear mechanisms indicated that texturing did not change the wear mechanisms, but altered their importance to tool wear. The anchoring provided by the higher roughness of the textured surface increased the adhesion of the coating on the substrate, thus increasing tool life. Additionally, the chemical modification of the carbide grains due to the laser heating might be responsible for an enhanced adhesion between coating and substrate.

  11. Evaluation of sputum culture conversion as a prognostic marker for end-of-treatment outcome inpatients with multidrug-resistant tuberculosis

    PubMed Central

    Kurbatova, Ekaterina V.; Cegielski, J. Peter; Lienhardt, Christian; Akksilp, Rattanawadee; Bayona, Jaime; Becerra, Mercedes C.; Caoili, Janice; Contreras, Carmen; Dalton, Tracy; Danilovits, Manfred; Demikhova, Olga V.; Ershova, Julia; Gammino, Victoria M.; Gelmanova, Irina; Heilig, Charles M.; Jou, Ruwen; Kazennyy, Boris; Keshavjee, Salmaan; Kim, Hee Jin; Kliiman, Kai; Kvasnovsky, Charlotte; Leimane, Vaira; Mitnick, Carole D.; Quelapio, Imelda; Riekstina, Vija; Smith, Sarah E.; Tupasi, Thelma; van der Walt, Martie; Vasilyeva, Irina A.; Via, Laura E.; Viiklepp, Piret; Volchenkov, Grigory; Walker, Allison Taylor; Wolfgang, Melanie; Yagui, Martin; Zignol, Matteo

    2015-01-01

    Background To assess the validity of sputum culture conversion (SCC) on solid media at varying time points and the time to SCC as prognostic markers for end-of-treatment outcome in multidrug-resistant (MDR) tuberculosis (TB) patients. Methods Data on1,712 MDR-TB patients from two large cohort studies were analyzed. Measures of association were determined using random effects multivariable logistic regression. Predictive values were calculated using bivariate random-effects generalized linear mixed model. Findings Times to SCC and SCC status at 6 months were significantly associated with treatment success compared to failure or death. SCC status at 2 months was significantly associated with treatment success among patients without known HIV infection only. The overall association of SCC with a successful outcome was substantially stronger at 6 months (adjusted odds ratio [aOR]=14.07, 95% CI 10.05–19.71) than at 2 months (HIV-negative patients: aOR=4.12 [2.25–7.54]; HIV unknown: aOR=3.59 [1.96–6.58], HIV-positive: aOR=0.38 [0.12–1.18]). The 2-month SCC had low sensitivity (27%) and high specificity (90%) for predicting treatment success. Conversely, 6-month SCC status had high sensitivity (92%), but moderate specificity (58%). The maximum combined sensitivity and specificity for SCC was reached between the 6th and 10th month of treatment. Interpretation Time to SCC, SCC status at 6 months, and SCC status at 2 months among patients without known HIV infection can be considered proxy markers of end-of-treatment outcome in MDR-TB patients, but the overall association with treatment success is substantially stronger for 6-month compared to 2-month SCC. Funding USAID, the US CDC, the Division of Intramural Research of NIAID/NIH, and the Republic of Korea’s CDC. PMID:25726085

  12. Peculiarities of the formation of multicomponent AlN-TiB2-TiSi2 composite ceramics coatings during heat treatment

    NASA Astrophysics Data System (ADS)

    Pogrebnyak, A. D.; Kravchenko, Yu. A.; Dem'yanenko, A. A.; Sobol', O. V.; Beresnev, V. M.; Pshik, A. V.

    2015-06-01

    Results of studies of the morphology, elemental and phase compositions of coatings prepared by pulsed magnetron sputtering of the AlN-TiB2-TiSi2 composite ceramic target have been reported. The used technology allows us to prepare a protective amorphous-like layer with ordering areas with sizes up to 1 nm. The heat treatment of samples at 900 and 1300°C leads to the depletion of the coating surface of boride phases and the formation of α-Al2O3- and β]-TiO2-based protective films on the surface. The growth of crystallites of the nanostructured coating to 11-25 nm is observed. The annealing at 1300°C allows us to obtain the thermally stable crystalline state of substance, the nanohardness of which is 11 GPa.

  13. Effects of heat treatment on microstructure and mechanical properties of Ni60/h-BN self-lubricating anti-wear composite coatings on 304 stainless steel by laser cladding

    NASA Astrophysics Data System (ADS)

    Lu, Xiao-Long; Liu, Xiu-Bo; Yu, Peng-Cheng; Zhai, Yong-Jie; Qiao, Shi-Jie; Wang, Ming-Di; Wang, Yong-Guang; Chen, Yao

    2015-11-01

    Laser clad Ni60/h-BN self-lubricating anti-wear composite coating on 304 stainless steel were heat treated at 600 °C (stress relief annealing) for 1 h and 2 h, respectively. Effects of the phase compositions, microstructure, microhardness, nano-indentation and tribological properties of the composite coatings with and without heat treatment had been investigated systemically. Results indicated that three coatings mainly consist of the matrix γ-(Ni, Fe) solid solution, the CrB ceramic phases and the h-BN lubricating phases. The maximum microhardness of the coatings was first increased from 667.7 HV0.5 to 765.0 HV0.5 after heat treatment for 1 h, and then decreased to 698.3 HV0.5 after heat treatment for 2 h. The hardness of γ-(Ni, Fe) solid solution without heat treatment and after heat treatment 1 h and 2 h were 5.09 GPa, 7.20 GPa and 3.77 GPa, respectively. Compared with the coating without heat treatment, the friction coefficients of the coating after heat treatment were decreased obviously. Effects of the heat treatment time on friction coefficient were negligible, but were significant on wear volume loss. Comparatively speaking, the laser clad self-lubricating anti-wear composite coating after heat treatment for 1 h presented the best anti-wear and friction reduction properties.

  14. Influence of carbon nanotubes coatings onto carbon fiber by oxidative treatments combined with electrophoretic deposition on interfacial properties of carbon fiber composite

    NASA Astrophysics Data System (ADS)

    Deng, Chao; Jiang, Jianjun; Liu, Fa; Fang, Liangchao; Wang, Junbiao; Li, Dejia; Wu, Jianjun

    2015-12-01

    To improve the interfacial performance of carbon fiber (CF) and epoxy resin, carbon nanotubes (CNTs) coatings were utilized to achieve this purpose through coating onto CF by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition (EPD) process. The influence of electrophoretically deposited CNTs coatings on the surface properties of CFs were investigated by Fourier transform infrared spectrometer, atomic force microscopy, scanning electron microscopy and dynamic contact angle analysis. The results indicated that the deposition of carbon nanotubes introduced some polar groups to carbon fiber surfaces, enhanced surface roughness and changed surface morphologies of carbon fibers. Surface wettability of carbon fibers may be significantly improved by increasing surface free energy of the fibers due to the deposition of CNTs. The thickness and density of the coatings increases with the introduction of pretreatment of the CF during the EPD process. Short beam shear test was performed to examine the effect of carbon fiber functionalization on mechanical properties of the carbon fiber/epoxy resin composites. The interfacial adhesion of CNTs/CF reinforced epoxy composites showed obvious enhancement of interlaminar shear strength by 60.2% and scanning electron microscope photographs showed that the failure mode of composites was changed after the carbon fibers were coated with CNTs.

  15. SILANE-BASED CONVERSION COATING FOR METALS

    EPA Science Inventory

    For the past three years, a project to develop new pretreatment rinses for metals was carried out by the U.S. Environmental Protection Agency and the University of Cincinnati. The project involved optimization of laboratory rinses with dilute aqueous solutions organofunctional s...

  16. SILANE-BASED CONVERSION COATING FOR METALS

    EPA Science Inventory

    For the past three years, a project to develop new pretreatment rinses for metals was carried out by the U.S. Environmental Protection Agency and the University of Cincinnati. The project involved optimization of laboratory rinses with dilute aqueous solutions organofunctional s...

  17. Up-Conversion Y2O3:Yb(3+),Er(3+) Hollow Spherical Drug Carrier with Improved Degradability for Cancer Treatment.

    PubMed

    Ge, Kun; Zhang, Cuimiao; Sun, Wentong; Liu, Huifang; Jin, Yi; Li, Zhenhua; Liang, Xing-Jie; Jia, Guang; Zhang, Jinchao

    2016-09-28

    The rare earth hollow spheres with up-conversion luminescence properties have shown potential applications in drug delivery and bioimaging fields. However, there have been few reports for the degradation properties of rare earth oxide drug carriers. Herein, uniform and well-dispersed Y2O3:Yb(3+),Er(3+) hollow spheres (YOHSs) have been fabricated by a general Pechini sol-gel process with melamine formaldehyde colloidal spheres as template. The novel YOHSs with up-conversion luminescence has good drug loading amount and drug-release efficiency; moreover, it exhibits pH-responsive release patterns. In particular, the YOHSs sample exhibits low cytotoxicity and excellent degradable properties in acid buffer. After the sample was loaded with anticancer drug doxorubicin (DOX), the antitumor result in vitro indicates that YOHS-DOX might be effective in cancer treatment. The animal imaging test also reveals that the YOHSs drug carrier can be used as an outstanding luminescent probe for bioimaging in vivo application prospects. The results suggest that the degradable drug carrier with up-conversion luminescence may enhance the delivery efficiency of drugs and improve the cancer therapy in clinical applications.

  18. Paclitaxel-coated balloon for the treatment of drug-eluting stent restenosis: subanalysis results from the Valentines I trial.

    PubMed

    Loh, Joshua P; Stella, Pieter R; Sangiorgi, Giuseppe; Silber, Sigmund; Stahnke, Stefanie; von Strandmann, Rembert Pogge; Torguson, Rebecca; Waksman, Ron

    2014-01-01

    To analyze the effect of paclitaxel-coated balloon (PCB) treatment on patients with drug-eluting stent (DES) restenosis. In the Valentines I trial, treatment of coronary in-stent restenosis was effective and safe with the second-generation DIOR® PCB. Valentines I prospectively enrolled 250 patients with in-stent restenosis (ISR); 76 patients (30.4%) had restenosis of a previous paclitaxel or limus DES. Patients underwent balloon angioplasty followed by PCB treatment. Clinical outcomes of patients with paclitaxel-eluting DES restenosis (n=34; 41 lesions) and limus-eluting (sirolimus, everolimus and zotarolimus) DES restenosis (n=42; 43 lesions) treated with DIOR® PCB were compared. Baseline characteristics were similar. There were more diffuse lesions >20mm treated in paclitaxel- compared to limus-eluting DES restenosis (50% vs. 26.8%, p=0.032). Number of PCB used per patient (1.08±0.31 overall), mean PCB diameter (2.99±0.42mm overall), mean PCB length (24.4±11.9mm overall), and bailout stenting (2.4% vs. 4.7%) were similar (p=NS). At mean follow-up of 231±43days, major adverse cardiac events was 0% vs. 23.8% in paclitaxel- vs. limus-eluting DES restenosis (p=0.002), driven mainly by less target vessel revascularization (0% vs. 21.4%, p=0.004). Target lesion revascularization was 0% vs. 16.7% for paclitaxel- vs. limus-eluting DES restenosis (p=0.015). In Valentines I, PCB use was more effective in patients with paclitaxel DES restenosis compared to limus DES restenosis, achieving better mid-term clinical outcomes. This suggests the efficacy of localized paclitaxel delivery to overcome paclitaxel resistance but not limus resistance due to different mechanisms of DES failure. © 2014.

  19. Anaerobic fluid-bed treatment of coal conversion wastewater: Second quarterly technical progress report for the period November 16, 1986-February 15, 1987

    SciTech Connect

    Suidan, M.T.; Pfeffer, J.T.; Nakhla, G.F.; Traegner, U.K.

    1987-01-01

    The objectives of the research project are to determine, using simultaneous experimental and modeling strategies, the effects of the hydraulic detention time and the schedule of granular activated carbon (GAC) replacement on the performance of the expanded-bed GAC anaerobic reactor during the treatment of biologically inhibiting coal conversion wastewaters. The hydraulic detention time and the associated carbon inventory represents the single most important capital cost parameter while GAC replacement, which is needed to maintain the concentrations of toxic compounds below threshold levels, represents a major operating cost parameter.

  20. Titania Coated Mica via Chemical Vapour Deposition, Post N-doped by Liquid Ammonia Treatment

    NASA Astrophysics Data System (ADS)

    Powell, Michael J.; Parkin, Ivan P.

    TiO2 films were successfully grown on synthetic mica powders via Chemical Vapor Deposition (CVD). The CVD rig is a cold-walled design that allows surface coverage of a powder to be successfully achieved. The TiO2 was produced by the reaction between TiCl4 and Ethyl Acetate. The powder produced could be successfully N-doped using post liquid ammonia treatment. The TiO2 powder produced could have potential applications in self-cleaning surfaces or antimicrobial paints.

  1. [Experimental studies of using polyester-coated materials of Polish production in surgical treatment of retinal detachment].

    PubMed

    Kmera-Muszyńska, M; Kecik, T; Pratnicki, A; Zajkowska, G; Wael, I

    1991-01-01

    The authors evaluated the tolerance of the rabbit eye to a new generation of polyester bands coated by polymethane polyester or by silicone. Investigations consisted on the application of episcleral implants made from polyester coated bands and--for comparison--of already well known polyester non-coated bands The eyes were removed on the 4th, 10th, 30th, 60th and 90th day after operation, macroscopically evaluated and fixed in formaline. The specimen were prepared from the spot of the applied implant together with a margin of surrounding tissues. Clinical observations, macroscopic evaluations as well as histopathological examinations showed a good tolerance of the silicone coated bands; it was discovered instead that the polyurethane coated bands are causing a more pronounced inflammatory reaction in the early postoperative period.

  2. The influence of discharge power and heat treatment on calcium phosphate coatings prepared by RF magnetron sputtering deposition.

    PubMed

    Yonggang, Yan; Wolke, J G C; Yubao, Li; Jansen, J A

    2007-06-01

    Ca-P coatings with different Ca/P ratio and composition were successfully prepared by RF magnetron sputtering deposition. The Ca/P ratio, phase composition, structure and morphological properties were characterized by XRD, FTIR, EDS and SEM analyses. All the as-sputtered coatings were amorphous and after IR-irradiation the coatings altered into a crystalline phase. The obtained coatings had a Ca/P ratio that varied from 0.55 to 2.10 and different phase compositions or mixtures of apatite, beta-pyrophosphate and beta-tricalciumphosphate structures were formed. Evidently, the phase compositions of the sputtered coatings are determined not only by the discharge power ratio of the hydroxylapatite and calcium pyrophosphate targets but also by the annealing temperature.

  3. Efficiency enhancement of flexible Cu(In,Ga)Se2 solar cells deposited on polyimide-coated soda lime glass substrate by alkali treatment

    NASA Astrophysics Data System (ADS)

    Sadono, Adiyudha; Ogihara, Tomohiro; Hino, Masashi; Yamamoto, Kenji; Nakada, Kazuyoshi; Yamada, Akira

    2017-08-01

    Alkali treatment effects on Cu(In,Ga)Se2 (CIGS) solar cells deposited on polyimide-coated soda lime glass (PI-coated SLG) were investigated. CIGS on PI-coated SLG shows Na diffusion from the substrate, which should be controlled to obtain high efficiencies. Further incorporation of Na was achieved by enhancing diffusion from the substrate or by external incorporation using post-deposition treatment (PDT) methods. Both methods lead to a high efficiency of approximately 15%. Moreover, aside from Na, K was also incorporated by KF-PDT, resulting in efficiency improvement from 12% for an untreated CIGS to more than 18% at the maximum substrate temperature of 450 °C, which is comparable to CIGS deposited at higher temperatures using the same equipment. It was also found that the alkali concentration of CIGS deposited on PI-coated SLG shows almost the same behavior as that of a film deposited on a rigid glass, suggesting that the deposition technique for CIGS on the rigid glass can be applied to flexible substrates.

  4. Influence of Pulse Electrodeposition and Heat Treatment on Microstructure, Tribological, and Corrosion Behavior of Nano-Grain Size Co-W Coatings

    NASA Astrophysics Data System (ADS)

    Abazari, Somayeh; Rastegari, Saeed; Kheirandish, Shahram

    2017-07-01

    In the present study, Co-W nano-structured alloy coatings are produced on low-carbon steel substrate by means of pulse electrodeposition from a citrate-based bath under different average current densities and duty cycles. The results indicate that the coating deposited under 60% of duty cycle and 1 A/dm2 of average current density exhibit optimum pulse plating conditions with 44.38 wt.% W, 37 nm grain size, and 758 HV microhardness. The effect of heat treatment temperature on microstructure, composition, corrosion behavior, and morphology of amorphous deposited Co-W alloy with 44 wt.% W was investigated. The microhardness of the coating increased to 1052 HV after heat treatment at 600 °C, which is due to the formation of Co3W and CoWO4 phases in the deposit. Furthermore, the coatings heat-treated at 600 °C had lower friction coefficients and better wear resistance under various loads than before heating.

  5. Low molecular weight chitosan-coated silver nanoparticles are effective for the treatment of MRSA-infected wounds.

    PubMed

    Peng, Yinbo; Song, Chenlu; Yang, Chuanfeng; Guo, Qige; Yao, Min

    2017-01-01

    Silver nanoparticles (AgNPs) are being widely applied as topical wound materials; however, accumulated deposition of silver in the liver, spleen, and other main organs may lead to organ damage and dysfunction. We report here that low molecular weight chitosan-coated silver nanoparticles (LMWC-AgNPs) are effective against methicillin-resistant Staphylococcus aureus (MRSA), have better biocompatibility, and have lower body absorption characteristics when compared with polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) and silver nanoparticles without surface stabilizer (uncoated-AgNPs) in a dorsal MRSA wound infection mouse model. LMWC-AgNPs were synthesized by reducing silver nitrate with low molecular weight chitosan as a stabilizer and reducing agent, while PVP-AgNPs were synthesized using polyvinylpyrrolidone as a stabilizer and ethanol as a reducing agent. AgNPs with different surface stabilizers were identified by UV-visible absorption spectrometry, and particle size was determined by transmission electron microscopy. UV-visible absorption spectra of LMWC-AgNPs, PVP-AgNPs and uncoated-AgNPs were similar and their sizes were in the range of 10-30 nm. In vitro experiments showed that the three types of AgNPs had similar MRSA-killing effects, with obvious effect at 4 μg/mL and 100% effect at 8 μg/mL. Bacteriostatic annulus experiments also showed that all the three types of AgNPs had similar antibacterial inhibitory effect at 10 μg/mL. Cell counting kit-8 assay and Hoechst/propidium iodide (PI) staining showed that LMWC-AgNPs were significantly less toxic to human fibroblasts than PVP-AgNPs and uncoated-AgNPs. Treatment of mice with MRSA wound infection demonstrated that the three types of AgNPs effectively controlled MRSA wound infection and promoted wound healing. After continuous application for 14 days, LMWC-AgNPs-treated mice showed significantly reduced liver dysfunction as demonstrated by the reduced alanine aminotransferase and aspartate

  6. Low molecular weight chitosan-coated silver nanoparticles are effective for the treatment of MRSA-infected wounds

    PubMed Central

    Peng, Yinbo; Song, Chenlu; Yang, Chuanfeng; Guo, Qige; Yao, Min

    2017-01-01

    Silver nanoparticles (AgNPs) are being widely applied as topical wound materials; however, accumulated deposition of silver in the liver, spleen, and other main organs may lead to organ damage and dysfunction. We report here that low molecular weight chitosan-coated silver nanoparticles (LMWC-AgNPs) are effective against methicillin-resistant Staphylococcus aureus (MRSA), have better biocompatibility, and have lower body absorption characteristics when compared with polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) and silver nanoparticles without surface stabilizer (uncoated-AgNPs) in a dorsal MRSA wound infection mouse model. LMWC-AgNPs were synthesized by reducing silver nitrate with low molecular weight chitosan as a stabilizer and reducing agent, while PVP-AgNPs were synthesized using polyvinylpyrrolidone as a stabilizer and ethanol as a reducing agent. AgNPs with different surface stabilizers were identified by UV-visible absorption spectrometry, and particle size was determined by transmission electron microscopy. UV-visible absorption spectra of LMWC-AgNPs, PVP-AgNPs and uncoated-AgNPs were similar and their sizes were in the range of 10–30 nm. In vitro experiments showed that the three types of AgNPs had similar MRSA-killing effects, with obvious effect at 4 μg/mL and 100% effect at 8 μg/mL. Bacteriostatic annulus experiments also showed that all the three types of AgNPs had similar antibacterial inhibitory effect at 10 μg/mL. Cell counting kit-8 assay and Hoechst/propidium iodide (PI) staining showed that LMWC-AgNPs were significantly less toxic to human fibroblasts than PVP-AgNPs and uncoated-AgNPs. Treatment of mice with MRSA wound infection demonstrated that the three types of AgNPs effectively controlled MRSA wound infection and promoted wound healing. After continuous application for 14 days, LMWC-AgNPs-treated mice showed significantly reduced liver dysfunction as demonstrated by the reduced alanine aminotransferase and aspartate

  7. Oxygen plasma pre-treatment improves the wear properties of a diamond-like carbon film coated on UHMWPE and PMMA for biomaterials.

    PubMed

    Ozeki, K; Kobayashi, S; Hirakuri, K K; Aoki, H; Fukui, Y

    2007-01-01

    Diamond-like carbon (DLC) films were deposited on ultra-high molecular weight polyethylene (UHMWPE) and polymethylmethacrylate (PMMA) with oxygen plasma pre-treatment using a radiofrequency plasma chemical vapour deposition method. A ball-on-disc test was carried out to evaluate the wear properties of the DLC-coated UHMWPE and PMMA. After testing, the surface of the polymers was observed using an atomic force microscope and an optical microscope. The adhesive strength of the DLC films deposited on the polymers was measured using a scratch test. After the ball-on-disc test, many cracks were observed in the films on the surface of both the DLC-coated UHMWPE and PMMA without the oxygen plasma pre-treatment, whereas the DLC-coated UHMWPE and PMMA with oxygen plasma pre-treatment showed no cracks and good wear resistance. In the scratch test, the adhesion strength of the DLC film to the PMMA substrate increased from 42.5 mN to 101.3 mN with oxygen plasma pre-treatment.

  8. Paclitaxel-Coated Balloons for the Treatment of Dysfunctional Dialysis Access. Results from a Single-Center, Retrospective Analysis.

    PubMed

    Kitrou, Panagiotis M; Spiliopoulos, Stavros; Papadimatos, Panagiotis; Christeas, Nicolaos; Petsas, Theodoros; Katsanos, Konstantinos; Karnabatidis, Dimitris

    2017-01-01

    To investigate the safety and effectiveness of lutonix paclitaxel-coated balloon (PCB) for the treatment of dysfunctional dialysis access. This was a single-center, single-arm, retrospective analysis of 39 patients (23 male, 59 %) undergoing 61 interventions using 69 PCBs in a 20-month period. There was a balance between arteriovenous fistulae (AVF) and grafts (AVG) (20 AVFs, 19AVGs), and the majority of lesions were restenotic (25/39, 64.1 %). Mean balloon diameter used was 6.6 mm and length 73.4 mm. Primary outcome measure was target lesion primary patency (TLPP) at 6 months, while secondary outcome measures included factors affecting TLPP and major complications. As there were lesions treated more than once with PCB, authors also compared patency results after first and second PCB angioplasty. TLPP was 72.2 % at 6 months with a median patency of 260 days according to the Kaplan-Meier survival analysis. No major complications occurred. TLPP between AVFs and AVGs (311 vs. 237 days, respectively; p = 0.29) and de novo and restenotic lesions was similar (270.5 vs. 267.5 days, respectively; p = 0.50). In 14 cases, in which lesions were treated with two PCB angioplasties, a statistically significant difference in TLPP after the second treatment was noted (first intervention 179.5 days vs. second intervention 273.5 days; p = 0.032). In this retrospective analysis, Lutonix PCB proved to be safe and effective in treating restenosis in dysfunctional dialysis access with results comparable to the literature available. Larger studies are needed to prove abovementioned results.

  9. Galactomannan gum coated mucoadhesive microspheres of glipizide for treatment of type 2 diabetes mellitus: In vitro and in vivo evaluation.

    PubMed

    Gaba, Punam; Singh, Sarbjot; Gaba, Monika; Gupta, G D

    2011-07-01

    Type 2 diabetes mellitus is a heterogeneous disease of polygenic origin and involves both defective insulin secretion and peripheral insulin resistance. Studies have shown that post-meal hyperglycemic spikes are associated with increased cardiovascular mortality in type 2 diabetes. Over the past decade, a major interest in control of postprandial glucose excursion has emerged and a plethora of new medications that specifically target postprandial hyperglycemia were discovered. Despite the availability of new agents for treatment of type 2 diabetes mellitus, oral sulfonylureas remain a cornerstone of therapy, because they are relatively inexpensive and are well tolerated. However, hypoglycemia is a major safety concern with sulfonylureas and it is one major risk factor requiring hospitalization. Glipizide is a potent, rapid-acting with short duration of action and well tolerated second-generation sulfonylurea effective in reducing postprandial glucose levels. However, risk of postprandial hypoglycemia and post-meal glucose excursions, if dose missed before meal; are always associated with the use of glipizide for treatment of type 2 diabetes mellitus. Since, the site of absorption of glipizide is from stomach thus dosage forms that are retained in stomach by mucoadhesion; would increase absorption, improve drug efficiency and decrease dose requirements. Microsphere carrier systems made by using polymer galactomannan having strong mucoadhesive properties and easily biodegradable could be an attractive strategy to formulate. The purpose of this research work is to formulate galactomannan coated mucoadhesive microspheres of glipizide and systematically evaluate its in vitro characteristics and in vivo performance for sustained glucose lowering effect and improvement in diabetic condition as compared to immediate release of glipizide.

  10. Conversational Telugu.

    ERIC Educational Resources Information Center

    Beinstein, Judith; And Others

    The purpose of this text is to develop elementary conversational skills in Telugu. The language materials consist of four types of language learning activities. The first, and most predominant, is the unit microwave cycle. These cycles divide the learning process into two basic phases, the first of which involves mimicry, memorization, and…

  11. Conversational Tamil.

    ERIC Educational Resources Information Center

    Beinstein, Judith; And Others

    The purpose of this text is to develop conversational skills in Tamil. It is to be used as a review of what has been learned in class and not as a teaching device. The language materials consist of four types of language learning activities. The unit microwave cycle divides the learning process into two basic phases. The first phase involves…

  12. Effects of WC-17Co Coating Combined with Shot Peening Treatment on Fatigue Behaviors of TC21 Titanium Alloy

    PubMed Central

    Du, Dongxing; Liu, Daoxin; Zhang, Xiaohua; Tang, Jingang; Meng, Baoli

    2016-01-01

    The improvement and mechanism of the fatigue resistance of TC21 high-strength titanium alloy with a high velocity oxygen fuel (HVOF) sprayed WC-17Co coating was investigated. X-ray diffraction (XRD) and the corresponding stress measurement instrument, a surface roughness tester, a micro-hardness tester, and a scanning electron microscope (SEM) were used to determine the properties of the HVOF WC-17Co coating with or without shot peening. The fatigue behavior of the TC21 titanium alloy with or without the WC-17Co coating was determined by using a rotating bending fatigue testing machine. The results revealed that the polished HVOF sprayed WC-17Co coating had almost the same fatigue resistance as the TC21 titanium alloy substrate. This resulted from the polishing-induced residual surface compressive stress and a decrease in the stress concentration on the surface of the coating. Moderate-intensity shot peening of the polished WC-17Co coatings resulted in significant improvement of the fatigue resistance of the alloy. Furthermore, the fatigue life was substantially higher than that of the substrate, owing to the deep distribution of residual stress and high compressive stress induced by shot peening. The improved surface toughness of the coating can effectively delay the initiation of fatigue crack propagation. PMID:28773984

  13. Anaerobic fluid-bed treatment of coal conversion wastewater: Third quarterly technical progress report for the period February 16-May 15, 1987

    SciTech Connect

    Suidan, M.T.; Pfeffer, J.T.; Nakhala, G.F.; Traegner, U.K.

    1987-06-01

    Anaerobic fluidized-bed GAC reactors have been proven successful for the treatment of biologically inhibiting wastewaters such as coal conversion wastewaters. However, in treating such wastewaters, which contain compounds that not only resist biodegradation but also inhibit the degradation of other compounds, adsorption on granular activated carbon (GAC) is a viable strategy for the removal of these inhibitory compounds. Since the adsorptive capacity of the reactor media is limited, partial replacement of the carbon bed is then necessary to maintain the concentration of inhibitory compounds below threshold levels. The cost of the GAC replacement thus represents a major operating cost of the system. The hydraulic detention time and the associated carbon inventory represents the single most important capital cost parameter. The objectives of this research are to determine, using experimental and modeling strategies, the effects of hydraulic detention time and the schedule of GAC replacement on the performance of fluidized bed GAC anaerobic reactors during the treatment of coal conversion wastewater. This objective is realized by the described activities.

  14. Anaerobic fluid-bed treatment of coal conversion wastewater: Eighth quarterly technical progress report for the period May 15, 1988--August 15, 1988

    SciTech Connect

    Suidan, M.T.; Pfeffer, J.T.; Nakhla, G.F.; Traegner, U.K.

    1988-01-01

    Anaerobic fluidized-bed GAC reactors have been proven successful for the treatment of biologically inhibiting wastewaters such as coal conversion wastewaters. However, in treating such wastewaters which contain compounds that not only resist biodegradation but also inhibit the degradation of other compounds, adsorption on granular activated carbon (GAC) represents a viable strategy for the removal of these inhibitory compounds. Since the adsorptive capacity of the reactor media is limited, partial replacement of the carbon bed is then necessary to maintain the concentration of inhibitory compounds below threshold levels. The cost of the GAC replacement thus represents a major operating cost of the system. The hydraulic detention time and the associated carbon inventory represent the single most important capital cost parameter. The objectives of this research are to determine, using experimental and modeling strategies, the effects of hydraulic detention time and the schedule of GAC replacement on the performance of fluidized-bed GAC anaerobic reactors during the treatment of coal conversion wastewater. 1 ref., 3 figs., 1 tab.

  15. Anaerobic fluid-bed treatment of coal conversion wastewater: Sixth quarterly technical progress report for the period November 15, 1987 to February 15, 1988

    SciTech Connect

    Suidan, M.T.; Pfeffer, J.T.; Nakhla, G.F.; Traegner, U.K.

    1988-01-01

    Anaerobic fluidized-bed GAC reactors have been proven successful for the treatment of biolgoically inhibiting watewaters such as coal conversion wastewaters. However, in treating such wastewaters which contain compounds that not only resist biodegradation but also inhibit the degradation of other compounds, adsorption on granular activated carbon (GAC) represent a viable strategy for the removal of these inhibitory compounds. Since the adsorptive capacity of the reactor media is limited, partial replacement of the carbon bed is then necessary to maintain the concentration of inhibitory compounds below threshold levels. The cost of the GAC replacement thus represents a major operating cost of the system. The hydraulic detention time and the assoicated carbon inventory represent the single most important capital cost parameter. The objectives of this research are to determine, using experimental and modeling strategies, the effects of hydraulic detention time and the schedule of GAC replacement on the performance of fluidized bed GAC anaerobic reactors during the treatment of coal conversion wastewater. 1 ref., 1 tab.

  16. Anaerobic fluid-bed treatment of coal conversion wastewater: Fourth quarterly technical progress report for the period May 15 to August 15, 1987

    SciTech Connect

    Suidan, M.T.; Pfeffer, J.T.; Nakhala, G.F.; Traegner, U.K.

    1987-01-01

    Anaerobic fluidized-bed GAC reactors have been proven successful for the treatment of biologically inhibiting wastewaters such as coal conversion wastewaters. However, in treating such wastewaters which contain compounds that not only resist biodegradation but also inhibit the degradation of other compounds, adsorption on granular activated carbon (GAC) is a viable strategy for the removal of these inhibitory compounds. Since the adsorptive capacity of the reactor media is limited, partial replacement of the carbon bed is then necessary to maintain the concentration of inhibitory compounds below threshold levels. The cost of the GAC replacement thus represents a major operating cost of the system. The hydraulic detention time and the associated carbon inventory represent the single most important capital cost parameter. The objectives of this research are to determine, using experimental and modeling strategies, the effects of hydraulic detention time and the schedule of GAC replacement on the performance of fluidized bed GAC anaerobic reactors during the treatment of coal conversion wastewater. 7 figs., 2 tabs.

  17. Thin-film optical notch filter spectacle coatings for the treatment of migraine and photophobia.

    PubMed

    Hoggan, Ryan N; Subhash, Amith; Blair, Steve; Digre, Kathleen B; Baggaley, Susan K; Gordon, Jamison; Brennan, K C; Warner, Judith E A; Crum, Alison V; Katz, Bradley J

    2016-06-01

    Previous evidence suggests optical treatments hold promise for treating migraine and photophobia. We designed an optical notch filter, centered at 480nm to reduce direct stimulation of intrinsically photosensitive retinal ganglion cells. We used thin-film technology to integrate the filter into spectacle lenses. Our objective was to determine if an optical notch filter, designed to attenuate activity of intrinsically photosensitive retinal ganglion cells, could reduce headache impact in chronic migraine subjects. For this randomized, double-masked study, our primary endpoint was the Headache Impact Test (HIT-6; GlaxoSmithKline, Brentford, Middlesex, UK). We developed two filters: the therapeutic filter blocked visible light at 480nm; a 620nm filter was designed as a sham. Participants were asked to wear lenses with one of the filters for 2weeks; after 2weeks when no lenses were worn, they wore lenses with the other filter for 2weeks. Of 48 subjects, 37 completed the study. Wearing either the 480 or 620nm lenses resulted in clinically and statistically significant HIT-6 reductions. However, there was no significant difference when comparing overall effect of the 480 and 620nm lenses. Although the 620nm filter was designed as a sham intervention, research published following the trial indicated that melanopsin, the photopigment in intrinsically photosensitive retinal ganglion cells, is bi-stable. This molecular property may explain the unexpected efficacy of the 620nm filter. These preliminary findings indicate that lenses outfitted with a thin-film optical notch filter may be useful in treating chronic migraine.

  18. Improved Treatment of Photothermal Cancer by Coating TiO2 on Porous Silicon.

    PubMed

    Na, Kil Ju; Park, Gye-Choon

    2016-02-01

    In present society, the technology in various field has been sharply developed and advanced. In medical technology, especially, photothermal therapy and photodynamic therapy have had limelight for curing cancers and diseases. The study investigates the photothermal therapy that reduces side effects of existing cancer treatment, is applied to only cancer cells, and dose not harm any other normal cells. The photothermal properties of porous silicon for therapy are analyzed in order to destroy cancer cells that are more weak at heat than normal ones. For improving performance of porous silicon, it also analyzes the properties when irradiating the near infrared by heterologously junction TiO2 and TiO2NW, photocatalysts that are very stable and harmless to the environment and the human body, to porous silicon. Each sample of Si, PSi, TiO2/Psi, and TiO2NW/PSi was irradiated with 808 nm near-IR of 300, 500, and 700 mW/cm2 light intensity, where the maximum heating temperature was 43.8, 61.6, 67.9, and 61.9 degrees C at 300 mW/cm2; 54.1, 64.3, 78.8, and 68.9 degrees C at 500 mW/cm2; and 97.3, 102.8, 102.5, and 95 0C at 700 mW/cm2. The time required to reach the maximum temperature was less than 10 min for every case. The results indicate that TiO2/PSi thin film irradiated with a single near-infrared wavelength of 808 nm, which is known to have the best human permeability, offers the potential of being the most successful photothermal cancer therapy agent. It maximizes the photo-thermal characteristics within the shortest time, and minimizes the adverse effects on the human body.

  19. Thin-film optical notch filter spectacle coatings for the treatment of migraine and photophobia

    PubMed Central

    Hoggan, Ryan N.; Subhash, Amith; Blair, Steve; Digre, Kathleen B.; Baggaley, Susan K.; Gordon, Jamison; Brennan, K.C.; Warner, Judith E.A.; Crum, Alison V.; Katz, Bradley J.

    2017-01-01

    Previous evidence suggests optical treatments hold promise for treating migraine and photophobia. We designed an optical notch filter, centered at 480 nm to reduce direct stimulation of intrinsically photosensitive retinal ganglion cells. We used thin-film technology to integrate the filter into spectacle lenses. Our objective was to determine if an optical notch filter, designed to attenuate activity of intrinsically photosensitive retinal ganglion cells, could reduce headache impact in chronic migraine subjects. For this randomized, double-masked study, our primary endpoint was the Headache Impact Test (HIT-6; GlaxoSmithKline, Brentford, Middlesex, UK). We developed two filters: the therapeutic filter blocked visible light at 480 nm; a 620 nm filter was designed as a sham. Participants were asked to wear lenses with one of the filters for 2 weeks; after 2 weeks when no lenses were worn, they wore lenses with the other filter for 2 weeks. Of 48 subjects, 37 completed the study. Wearing either the 480 or 620 nm lenses resulted in clinically and statistically significant HIT-6 reductions. However, there was no significant difference when comparing overall effect of the 480 and 620 nm lenses. Although the 620 nm filter was designed as a sham intervention, research published following the trial indicated that melanopsin, the photopigment in intrinsically photosensitive retinal ganglion cells, is bi-stable. This molecular property may explain the unexpected efficacy of the 620 nm filter. These preliminary findings indicate that lenses outfitted with a thin-film optical notch filter may be useful in treating chronic migraine. PMID:26935748

  20. Full-scale application of focused-pulsed pre-treatment for improving biosolids digestion and conversion to methane.

    PubMed

    Rittmann, Bruce E; Lee, Hyung-sool; Zhang, Husen; Alder, Jared; Banaszak, James E; Lopez, Ronald

    2008-01-01

    We tested at full-scale the innovative Focused Pulsed (FP) technology for pre-treating waste sludge in order to improve methane gas production and biosolids reduction in sludge digestion, but without incurring problems of odors, toxicity, and high costs for chemical or energy consumption. FP pre-treatment of a mixture of primary and secondary sludge increased the soluble COD by 160% and DOC 120% over the control. FP pre-treatment of 63% of the input waste sludge increased biogas production by over 40% and reduced biosolids requiring disposal by 30% when compared to the plant baseline. FP pre-treatment also correlated with a shift of the bacterial and archaeal communities. The most significant change was that the acetate-cleaving Methanosaeta became the dominant methanogen. Full FP pre-treatment should increase biogas production and biosolids removal by 60% and 40%, respectively. Full FP pre-treatment should generate energy benefits of at least 2.7 times and as high as 18 times the FP energy input, depending on heat recovery from FP treatment. For a plant treating 76,000 m3/d of wastewater (380 m3-sludge/d), FP treatment should generate an annual economic benefit of approximately $540,000 net of electricity and other operating and maintenance costs. This represents a payback period of three years or less.

  1. COATED ALLOYS

    DOEpatents

    Harman, C.G.; O'Bannon, L.S.

    1958-07-15

    A coating is described for iron group metals and alloys, that is particularly suitable for use with nickel containing alloys. The coating is glassy in nature and consists of a mixture containing an alkali metal oxide, strontium oxide, and silicon oxide. When the glass coated nickel base metal is"fired'' at less than the melting point of the coating, it appears the nlckel diffuses into the vitreous coating, thus providing a closely adherent and protective cladding.

  2. Aluminide coatings

    DOEpatents

    Henager, Jr; Charles, H [Kennewick, WA; Shin, Yongsoon [Richland, WA; Samuels, William D [Richland, WA

    2009-08-18

    Disclosed herein are aluminide coatings. In one embodiment coatings are used as a barrier coating to protect a metal substrate, such as a steel or a superalloy, from various chemical environments, including oxidizing, reducing and/or sulfidizing conditions. In addition, the disclosed coatings can be used, for example, to prevent the substantial diffusion of various elements, such as chromium, at elevated service temperatures. Related methods for preparing protective coatings on metal substrates are also described.

  3. Ti-WC nanocrystalline coating formed by surface mechanical attrition treatment process on 316L stainless steel.

    PubMed

    Aliofkhazraei, M; Rouhaghdam, A Sabour; Ghobadi, E

    2011-10-01

    Nanocrystalline coatings were performed on the surface of 316L stainless steel plates mechanically with a mixture of Ti and WC powders under vacuum conditions. The targets were replaced in the end of the high energy milling rig, while Ti-WC mixture was milled as usual. It is shown that the coatings are nanocrystalline in nature with narrow distribution of average size of nanocrystallites. X-ray diffraction and scanning electron microscopy (with energy-dispersive spectrometer) revealed that the top layer of the coatings is uniform. Microhardness, roughness and primary corrosion tests (tafel tests) proved enhancement of coated samples with respect to raw materials. Transmission electron microscope image of deformed surface confirmed surrounding of nanoparticles by dislocation loops after plastic deformation.

  4. Microstructural Evolution of 11Al-3Mg-Zn Ternary Alloy-Coated Steels During Austenitization Heat Treatment

    NASA Astrophysics Data System (ADS)

    Chang, Jun-Kai; Lin, Chao-Sung

    2017-08-01

    This study details the microstructural evolution of a commercial hot-dip 11Al-3Mg-Zn-coated steel during austenitization. After 5 minutes of austenitization at 1173 K (900 °C), the ternary alloy coating transformed to consist of a nearly pure Zn as the major layer, a Fe-Al alloy layer at the interface, and a thin oxide overlay. The Fe-Al alloy layer effectively acted as the inhibition layer to prevent Fe from diffusing and reacting with Zn, which in turn retained the molten Zn layer and the integrity of the surface oxide layer. Moreover, the potential difference between the 11Al-3Mg-Zn coating and the steel substrate remained similar after austenitization, signifying the resulting coating kept its sacrificial protection capability.

  5. Coatings for Graphite Fibers

    NASA Technical Reports Server (NTRS)

    Galasso, F. S.; Scola, D. A.; Veltri, R. D.

    1980-01-01

    Several approaches for applying high resistance coatings continuously to graphite yarn were investigated. Two of the most promising approaches involved (1) chemically vapor depositing (CVD) SiC coatings on the surface of the fiber followed by oxidation, and (2) drawing the graphite yarn through an organo-silicone solution followed by heat treatments. In both methods, coated fibers were obtained which exhibited increased electrical resistances over untreated fibers and which were not degraded. This work was conducted in a previous program. In this program, the continuous CVD SiC coating process used on HTS fiber was extended to the coating of HMS, Celion 6000, Celion 12000 and T-300 graphite fiber. Electrical resistances three order of magnitude greater than the uncoated fiber were measured with no significant degradation of the fiber strength. Graphite fibers coated with CVD Si3N4 and BN had resistances greater than 10(exp 6) ohm/cm. Lower pyrolysis temperatures were used in preparing the silica-like coatings also resulting in resistances as high as three orders of magnitude higher than the uncoated fiber. The epoxy matrix composites prepared using these coated fibers had low shear strengths indicating that the coatings were weak.

  6. Bone response to titanium implants coated with thin sputtered HA film subject to hydrothermal treatment and implanted in the canine mandible.

    PubMed

    Ozeki, K; Okuyama, Y; Fukui, Y; Aoki, H

    2006-01-01

    Hydroxyapatite (HA) was coated onto titanium implants using radio frequency magnetron sputtering. The HA films were crystallized in an autoclave tube using low temperature hydrothermal treatment. The average film thickness on the implant was 1.1 microm. HA-coated and pure-titanium implants were inserted into canine mandibles for up to 24 weeks. Forty-eight implants were placed in eight beagles. After 2, 4, 12 and 24 weeks, implants were retrieved and prepared for histological observation, and the HA film thickness was determined using energy-dispersive X-ray spectroscopy. Light microscopy revealed that, after two weeks, the bone response to the HA-coated implants was much better than to the pure titanium implants, and osteoblasts were observed at the bone-implant interface. After four weeks, the screw threads of the HA-coated implants were almost completely covered with bone. The HA film thickness rapidly decreased up to four weeks of implantation, then gently decreased, reaching 0.40+/-0.03 microm at the upper region of the implant after 12 weeks. That indicates that about 80% of the HA film had dissolved after 12 weeks of implantation. The rate of decrease in the HA film thickness was greater with increasing implant depth.

  7. Investigation of an active film coating to prepare new fixed-dose combination tablets for treatment of diabetes.

    PubMed

    Kim, Ju-Young; Kim, Dong-Wook; Kuk, Yun-Mo; Park, Chun-Woong; Rhee, Yun-Seok; Oh, Tack-Oon; Weon, Kwon-Yeon; Park, Eun-Seok

    2012-05-10

    The aim of the present study was to formulate new fixed-dose combination tablets (FCTs) by coating a glimepiride (GLM) immediate-release (IR) layer on a metformin hydrochloride (MTF) extended-release (ER) core tablet using perforated film coating equipment. Composition of GLM-IR coating suspension for homogeneity was studied and application of near-infrared spectroscopy (NIR) to determine the end-point of the coating process was also investigated. The final product was administered to healthy male volunteers and its pharmacokinetic parameters were analyzed. GLM-IR coating suspension was prepared with a ratio of SLS to GLM at 0.75 for homogeneity. An inert mid-layer was introduced to prevent contact between MTF-ER core tablet and GLM-IR layer, which led to an increased release rate of GLM in pH 7.8 medium. The proportional correlation was confirmed between analytical results of GLM determined by NIRS and those by HPLC-UV. Thus, the end-point of the GLM coating process was determined by NIRS, the fast and non-destructive method. New FCTs were confirmed to be bioequivalent to the marketed product. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. In situ regulating of surface morphologies, anti-corrosion and tribological properties of epoxy resin coatings by heat treatment

    NASA Astrophysics Data System (ADS)

    Liu, Dan; Zhao, Wenjie; Liu, Shuan; Cen, Qihong; Xue, Qunji

    2017-06-01

    A simple and in situ formation method through controlling curing temperature was used to regulate the surface morphology of epoxy resin (EP) coating. Multi-functional tribology test equipment and an electrochemistry workstation were used to evaluate the tribological and anti-corrosion properties of the EP coating cured with diethylenetriamine at room temperature, 80 °C, 100 °C and 120 °C, respectively. The results indicated that the diameter and depth of pores or pits existing on the surface of EP coatings decreased significantly with the increase of curing temperature. The EP coating cured at 120 °C exhibited the best tribological performance, the friction coefficient and wear trace area were 0.56 and 0.003 02 mm2 under dry conditions, 0.18 and 1.873  ×  10-5 mm2 under seawater conditions, respectively. The excellent tribological performance could be attributed to the surface morphologies and high hardness of EP coatings. The EP coating cured at 80 °C exhibited the best anti-corrosion performance that the impedance modulus at 0.01 Hz was close to 5.0 KΩ cm2 even after being immersed in 3.5 wt% NaCl solution for 24 h, which was closely related to its hydrophobic behavior and surface morphology.

  9. Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

    SciTech Connect

    Durmaz, M. Abakay, E.; Sen, U.; Sen, S.; Kilinc, B.

    2015-03-30

    In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr{sub 2}N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV{sub 0.025}. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

  10. Conversational sensing

    NASA Astrophysics Data System (ADS)

    Preece, Alun; Gwilliams, Chris; Parizas, Christos; Pizzocaro, Diego; Bakdash, Jonathan Z.; Braines, Dave

    2014-05-01

    Recent developments in sensing technologies, mobile devices and context-aware user interfaces have made it pos- sible to represent information fusion and situational awareness for Intelligence, Surveillance and Reconnaissance (ISR) activities as a conversational process among actors at or near the tactical edges of a network. Motivated by use cases in the domain of Company Intelligence Support Team (CoIST) tasks, this paper presents an approach to information collection, fusion and sense-making based on the use of natural language (NL) and controlled nat- ural language (CNL) to support richer forms of human-machine interaction. The approach uses a conversational protocol to facilitate a ow of collaborative messages from NL to CNL and back again in support of interactions such as: turning eyewitness reports from human observers into actionable information (from both soldier and civilian sources); fusing information from humans and physical sensors (with associated quality metadata); and assisting human analysts to make the best use of available sensing assets in an area of interest (governed by man- agement and security policies). CNL is used as a common formal knowledge representation for both machine and human agents to support reasoning, semantic information fusion and generation of rationale for inferences, in ways that remain transparent to human users. Examples are provided of various alternative styles for user feedback, including NL, CNL and graphical feedback. A pilot experiment with human subjects shows that a prototype conversational agent is able to gather usable CNL information from untrained human subjects.

  11. Conversational sensemaking

    NASA Astrophysics Data System (ADS)

    Preece, Alun; Webberley, Will; Braines, Dave

    2015-05-01

    Recent advances in natural language question-answering systems and context-aware mobile apps create opportunities for improved sensemaking in a tactical setting. Users equipped with mobile devices act as both sensors (able to acquire information) and effectors (able to act in situ), operating alone or in collectives. The currently- dominant technical approaches follow either a pull model (e.g. Apple's Siri or IBM's Watson which respond to users' natural language queries) or a push model (e.g. Google's Now which sends notifications to a user based on their context). There is growing recognition that users need more flexible styles of conversational interaction, where they are able to freely ask or tell, be asked or told, seek explanations and clarifications. Ideally such conversations should involve a mix of human and machine agents, able to collaborate in collective sensemaking activities with as few barriers as possible. Desirable capabilities include adding new knowledge, collaboratively building models, invoking specific services, and drawing inferences. As a step towards this goal, we collect evidence from a number of recent pilot studies including natural experiments (e.g. situation awareness in the context of organised protests) and synthetic experiments (e.g. human and machine agents collaborating in information seeking and spot reporting). We identify some principles and areas of future research for "conversational sensemaking".

  12. Paclitaxel-coated balloon catheter versus paclitaxel-coated stent for the treatment of coronary in-stent restenosis: the three-year results of the PEPCAD II ISR study.

    PubMed

    Unverdorben, Martin; Vallbracht, Christian; Cremers, Bodo; Heuer, Hubertus; Hengstenberg, Christian; Maikowski, Christian; Werner, Gerald S; Antoni, Diethmar; Kleber, Franz X; Bocksch, Wolfgang; Leschke, Matthias; Ackermann, Hanns; Boxberger, Michael; Speck, Ulrich; Degenhardt, Ralf; Scheller, Bruno

    2015-12-01

    Treatment of bare metal in-stent restenosis with the paclitaxel-coated balloon catheter based on the PACCOCATH® technology has yielded superior six-month angiographic and one-year clinical results compared to a paclitaxel-eluting stent. The three-year clinical follow-up is presented. One hundred and thirty-one patients with coronary bare metal in-stent restenosis (>70%, length: <22 mm, vessel diameter: 2.5-3.5 mm) were randomly treated with the paclitaxel-coated balloon (DCB) (3 µg/mm²) or a paclitaxel-eluting stent (DES). Clinical follow-up information was requested from the patients and from their physicians. Quantitative angiographic and demographic baseline data were statistically not different between the groups. Per intention-to-treat analysis at 12 months, the lesion-related rates of major adverse cardiac events were 7.6% and 16.9% (p=0.11) while at 36 months the respective numbers were 9.1% and 18.5% (p=0.14). These differences were primarily due to reduced target lesion revascularisation (TLR) in DCB 4/66 (6.2%) compared to DES patients 10/65 (15.4%) (p=0.10). From 12 to 36 months, 1/65 (1.5%) DCB patients experienced a myocardial infarction while neither TLR nor death occurred in any study patient in either group during that period. The six-month superiority of the paclitaxel-coated balloon compared to the paclitaxel-eluting stent in the treatment of bare metal coronary in-stent restenosis persisted throughout the three-year clinical follow-up period indicating stability of the lesions treated. (ClinicalTrials.gov Identifier: NCT00393315).

  13. Patient profiling can identify patients with adult spinal deformity (ASD) at risk for conversion from non-operative to surgical treatment: initial steps to reduce ineffective ASD management.

    PubMed

    Passias, Peter G; Jalai, Cyrus M; Line, Breton G; Poorman, Gregory W; Scheer, Justin K; Smith, Justin S; Shaffrey, Christopher I; Burton, Douglas C; Fu, Kai-Ming G; Klineberg, Eric O; Hart, Robert A; Schwab, Frank; Lafage, Virginie; Bess, Shay

    2017-07-05

    Non-operative management is a common initial treatment for patients with adult spinal deformity (ASD) despite reported superiority of surgery with regard to outcomes. Ineffective medical care is a large source of resource drain on the health system. Characterization of patients with ASD likely to elect for operative treatment from non-operative management may allow for more efficient patient counseling and cost savings. This study aimed to identify deformity and disability characteristics of patients with ASD who ultimately convert to operative treatment compared with those who remain non-operative and those who initially choose surgery. A retrospective review was carried out. A total of 510 patients with ASD (189 non-operative, 321 operative) with minimum 2-year follow-up comprised the patient sample. Oswestry Disability Index (ODI), Short-Form 36 Health Assessment (SF-36), Scoliosis Research Society questionnaire (SRS-22r), and spinopelvic radiographic alignment were the outcome measures. Demographic, radiographic, and patient-reported outcome measures (PROMs) from a cohort of patients with ASD prospectively enrolled into a multicenter database were evaluated. Patients were divided into three treatment cohorts: Non-operative (NON=initial non-operative treatment and remained non-operative), Operative (OP=initial operative treatment), and Crossover (CROSS=initial non-operative treatment with subsequent conversion to operative treatment). NON and OP groups were propensity score-matched (PSM) to CROSS for baseline demographics (age, body mass index, Charlson Comorbidity Index). Time to crossover was divided into early (<1 year) and late (>1 year). Outcome measures were compared across and within treatment groups at four time points (baseline, 6 weeks, 1 year, and 2 years). Following PSM, 118 patients were included (NON=39, OP=38, CROSS=41). Crossover rate was 21.7% (41/189). Mean time to crossover was 394 days. All groups had similar baseline sagittal alignment

  14. Next Generation Coatings

    DTIC Science & Technology

    2009-02-04

    Next Generation Coatings presented to US Army Corrosion Summit February 4, 2009 Terrence R. Giles Business Development Mgr Henkel Adhesive ...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Henkel Adhesive Technologies,Dusseldorf, Germany , 8. PERFORMING...2008 2009 January 2007 1st Auto Parts Conversion t t t i March 2007 2nd OEM Trial i l 4 Qtr 2008 - 2009 Global Roll Outs Automotive t - l

  15. Conversion of coal mine drainage ochre to water treatment reagent: Production, characterisation and application for P and Zn removal.

    PubMed

    Sapsford, Devin; Santonastaso, Marco; Thorn, Peter; Kershaw, Steven

    2015-09-01

    Coal mine drainage ochre is a ferruginous precipitate that forms from mine water in impacted watercourses and during treatment. With thousands of tonnes per annum of such ochre arising from mine water treatment in the UK alone, management of these wastes is a substantive issue. This paper demonstrates that the ochre from both active and passive treatment of coal mine drainage can be transformed into an effective water treatment reagent by simple acid dissolution and that the reagent can be used for the removal of dissolved phosphorous from municipal wastewater and zinc from non-coal mine waters. Ochre is readily soluble in H2SO4 and HCl. Ochre is more soluble in HCl with solubilities of up to 100 g/L in 20% (w/w) HCl and 68 g/L in 10% (w/w) H2SO4. For four of the eight tested ochres solubility decreased in higher concentrations of H2SO4. Ochre compositional data demonstrate that the coal mine ochres tested are relatively free from problematic levels of elements seen by other authors from acid mine drainage-derived ochre. Comparison to British Standards for use of iron-based coagulants in drinking water treatment was used as an indicator of the acceptability of use of the ochre-derived reagents in terms of potentially problematic elements. The ochre-derived reagents were found to meet the 'Grade 3' specification, except for arsenic. Thus, for application in municipal wastewater and mine water treatment additional processing may not be required. There was little observed compositional difference between solutions prepared using H2SO4 or HCl. Ochre-derived reagents showed applicability for the removal of P and Zn with removals of up to 99% and 97% respectively measured for final pH 7-8, likely due to sorption/coprecipitation. Furthermore, the results demonstrate that applying a Fe dose in the form of liquid reagent leads to a better Fe:P and Fe:Zn removal ratio compared to ochre-based sorption media tested in the literature. Copyright © 2015 The Authors. Published by

  16. Improved Manganese Phosphate Coatings

    DTIC Science & Technology

    1975-04-01

    Conversion coatings 3 . Phosphating bath 20 AGrjC onln odd*. ta It .. c..soMV midP 1J.,alft. by block noc.mb) Work was conducted to determine the mechanism by...34 TABULAR DATA Table I Analyses of Solution and Coating for Phosphating Baths 4 of Di-ferlng Compositions 11 Atomic Absorption...manganese and iron phosphate coating: k * a. Mn(H 2PO4) 2 Nn-P0 4 + H3PO0 k2 k) b. 3MnHPO4 - Mn3 (P04) 2 + H3i’O4 k4 k5 c. Fe(H 2PO4) 2 -01 FeHPO4

  17. Preparation and characterization of the hydrophilic nanocomposite coating based on epoxy resin and titanate on the glass substrate.

    PubMed

    Sadjadi, M S; Farhadyar, N

    2009-02-01

    The hydrophilic organic-inorganic nanocomposite hybrid coatings were prepared using Tetrabutyl titanate. A simple sol-gel method has been developed for the preparation of nanocomposite coatings, at a molecular level and providing suitable conditions to obtain a complete conversion. The films were prepared on the glass substrates by dip-coating from a sol containing alcoholic tetrabutyl titanate which after the curing treatment, the gel forms a stable thin homogeneous nanocomposite coating. The obtained films were transparent to visible light and their surface hydrophilicity values were increased by increasing titania content in the water damp permeable self leveling flooring system. Characterization of the nanocomposite coating were performed by Transmission electron microscopy (TEM), Atomic force microscopy (AFM) analysis and contact angle test for water on TiO2 films that gave evidence of a strong interaction between the organic and inorganic phase with the formation of titania domains in the nanoscale range.

  18. Treatment of near-skull brain tissue with a focused device using shear-mode conversion: a numerical study.

    PubMed

    Pichardo, Samuel; Hynynen, Kullervo

    2007-12-21

    Shear mode transmission through the skull has been previously proposed as a new trans-skull propagation technique for noninvasive therapeutic ultrasound (Clement 2004 J. Acoust. Soc. Am. 115 1356-64). The main advantage of choosing shear over longitudinal mode resides on the fact that there is less wavefront distortion with the former. In the present study, the regions of the brain suitable for shear-mode transmission were established for a simple focused ultrasound device. The device consists of a spherically curved transducer that has a focal length of 10 cm, an aperture between 30 degrees and 60 degrees and operates at 0.74 MHz. The regions suitable for shear-mode transmission were determined by the shear wave acoustic windows that matched the shape of the device acoustic field. The acoustic windows were calculated using segmentation and triangulation of outer and inner faces of skull from 3D-MRI head datasets. Nine heads of healthy adults were analyzed. The surface considered for the calculations was the head region found above the supra-orbital margin. For every inspected point in the brain volume, the axis of the device was determined by the vector between this inspection point and a point located in the center of the brain. Numerical predictions of the acoustic field, where shear-mode conversion through the skull was considered, were obtained and compared to the case of water-only conditions. The brain tissue that is close to the skull showed suitable acoustic windows for shear waves. The central region of the brain seems to be unreachable using shear-mode. Analysis of the acoustic fields showed a proportional relation between the acoustic window for shear mode and the effective degree of focusing. However, this relation showed significant differences among specimens. In general, highly focused fields were obtained when the acoustic window for shear waves (A(SW)) intersected more than 67% of the entering acoustic window (A(TX)) of the device. The average

  19. Microplasma jet treatment of bovine serum albumin coatings for controlling enzyme and cell attachment

    NASA Astrophysics Data System (ADS)

    Szili, Endre J.; Becker, Stefanie; Short, Robert D.; Al-Bataineh, Sameer A.

    2017-08-01

    We investigated a new approach to control protein and cell attachment inside 96-well polystyrene plates. The wells were first coated with bovine serum albumin (BSA) to inhibit cell and protein attachment. The BSA-coated wells were then treated with a helium microplasma jet for increasing times that resulted in gradual removal of BSA from the surface. It was found that the amount of enzyme and cell attachment could be controlled in the wells where BSA was only partially removed by the microplasma jet. In addition to the surface coverage of BSA, the new surface chemistry induced by the microplasma jet treatment also had an important role in the control of enzyme and cell attachment. In summary, microplasma jet treatment of BSA-coated polystyrene wells is a simple and effective method for controlling enzyme and cell attachment. This might find use for high-throughput screening of new cell culture platforms where control over the level protein, enzyme or cell adherence is needed in order to maintain a specific cell function.

  20. Treatment of femoropopliteal atherosclerotic lesions using the Ranger paclitaxel-coated balloon catheter - 12-month results from an all-comers registry.

    PubMed

    Lichtenberg, Michael; von Bilderling, Peter; Ranft, Jürgen; Niemöller, Kathrin; Grell, Holger; Briner, Lucas; Saucy, Françoise; Rassaf, Tienush; Breuckmann, Frank

    2017-10-03

    To evaluate 12-month effectiveness of the endovascular treatment of femoropopliteal (FP) atherosclerotic lesions with the Ranger drug-coated balloon (DCB) in a real-world setting. In this prospective, observational, multicenter trial (ClinicalTrials.gov Identifier: NCT02462005) 172 consecutive patients with 226 de novo, restenosed, or reoccluded native superficial femoral and/or popliteal artery lesions were treated with the Ranger paclitaxel- coated balloon angioplasty. Mean lesion length was 129 mm (5 - 400 mm). Fifty-nine (26%) of 226 lesions were moderately or heavily calcified. Provisional stenting was conducted in 55 (22%) of 226 lesions. Main effectiveness outcomes were procedural success, 6- and 12- month hemodynamic or clinical improvement, and primary patency based and clinically driven target lesion revascularization (TLR) at 6 and 12 months. Procedural success (<30% residual stenosis and no major adverse event within 30 days) was achieved in 126 (73%) of 172 patients with DCB alone and in all patients if bailout procedures were included. Primary patency was 91.0% at 6 months and 84.1% at 12 months. Freedom TLR was 92.4 % at 6 months and 89.2 % at 12 months. ABI, pain-free walking distance and Rutherford category improved significantly (p < 0.001) after 6 and 12 months. Results suggest that angioplasty with the Ranger paclitaxel-coated balloon with provisional stenting is efficacious for the treatment of a broad range of femoropopliteal atherosclerotic lesions. No safety concerns arose.

  1. Geochemically structural characteristics of municipal solid waste incineration fly ash particles and mineralogical surface conversions by chelate treatment.

    PubMed

    Kitamura, Hiroki; Sawada, Takaya; Shimaoka, Takayuki; Takahashi, Fumitake

    2016-01-01

    Leaching behaviors of heavy metals contained in municipal solid waste incineration (MSWI) fly ash have been studied well. However, micro-characteristics of MSWI fly ash particles are still uncertain and might be non-negligible to describe their leaching behaviors. Therefore, this study investigated micro-characteristics of MSWI fly ash particles, especially their structural properties and impacts of chelate treatment on surface characteristics. According to SEM observations, raw fly ash particles could be categorized into four types based on their shapes. Because chelate treatment changed the surface of fly ash particles dramatically owing to secondary mineral formations like ettringite, two more types could be categorized for chelate-treated fly ash particles. Acid extraction experiments suggest that fly ash particles, tested in this study, consist of Si-base insoluble core structure, Al/Ca/Si-base semi-soluble matrices inside the body, and KCl/NaCl-base soluble aggregates on the surface. Scanning electron microscope (SEM) observations of the same fly ash particles during twice moistening treatments showed that KCl/NaCl moved under wet condition and concentrated at different places on the particle surface. However, element mobility depended on secondary mineral formations. When insoluble mineral like gypsum was generated and covered the particle surface, it inhibited element transfer under wet condition. Surface characteristics including secondary mineral formation of MSWI fly ash particles are likely non-negligible to describe trace element leaching behaviors.

  2. A novel conversion of the groundwater treatment sludge to magnetic particles for the adsorption of methylene blue.

    PubMed

    Zhu, Suiyi; Fang, Shuai; Huo, Mingxin; Yu, Yang; Chen, Yu; Yang, Xia; Geng, Zhi; Wang, Yi; Bian, Dejun; Huo, Hongliang

    2015-07-15

    Iron sludge, produced from filtration and backwash of groundwater treatment plant, has long been considered as a waste for landfill. In this study, iron sludge was reused to synthesize Fe3O4 magnetic particles (MPs) by using a novel solvothermal process. Iron sludge contained abundant amounts of silicon, iron, and aluminum and did not exhibit magnetic properties. After treatment for 4h, the amorphous Fe in iron sludge was transformed into magnetite Fe3O4, which could be easily separated from aqueous solution with a magnet. The prepared particles demonstrated the intrinsic properties of soft magnetic materials and could aggregate into a size of 1 μm. MPs treated for 10h exhibited excellent magnetic properties and a saturation magnetization value of 9 emu/g. The obtained particles presented the optimal adsorption of methylene blue under mild conditions, and the maximum adsorption capacity was 99.4 mg/g, which was higher than that of granular active carbon. The simple solvothermal method can be used to prepare Fe3O4 MPs from iron sludge, and the products could be applied to treatment of dyeing wastewater.

  3. Effect of post-polymerization heat-treatments on degree of conversion, leaching residual MMA and in vitro cytotoxicity of autopolymerizing acrylic repair resin.

    PubMed

    Bural, Canan; Aktaş, Esin; Deniz, Günnur; Ünlüçerçi, Yeşim; Kızılcan, Nilgün; Bayraktar, Gülsen

    2011-11-01

    This study evaluated the effect of post-polymerization heat-treatments on degree of conversion (DC), residual methyl methacrylate concentration (MMA(r)) and in vitro cytotoxicity of autopolymerizing acrylic repair resin. A total of 336 specimens were prepared by bench- and hydroflask-curing and subjected to post-polymerization heat-treatments: a) water immersion at 60°C for 30 min, b) microwaving at 500 W for 3 min, c) combined use of water immersion and microwaving d) no treatment (as control). Specimens were eluted in cell culture medium for 1, 2, 5 and 7 days. DC and MMA(r) in eluates were measured by FTIR spectrometry and HPLC, respectively. In vitro cytotoxicity of eluates on L-929 fibroblasts was determined by XTT assay. Data were statistically analyzed with Dunn's multiple comparison and Pearson correlation tests (p≤0.05). DC was highest (99.9%) in bench- and hydroflask-cured groups which were subjected to water immersion. At all elution periods, MMA(r) was detected in eluates of all treatment groups and were higher in bench-cured groups than hydro-flask cured groups. Cell proliferation values indicated slightly cytotoxic effect throughout 7 days; regardless of the curing method or post-polymerization treatment. The correlation between MMA(r) and cell proliferation was negative after elution of 1, 2, 5 days and was only statistically significant (p<0.05) at 5 days. At elution of 7 days, the correlation was positive with no significance. Post-polymerization heat-treatment of autopolymerizing acrylic repair resin by immersion in water at 60°C for 30 min is clinically recommended to improve the DC while reducing the leaching residual MMA. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Low temperature conversion (LTC)--an alternative method to treat sludge generated in an industrial wastewater treatment station--batch and continuous process comparison.

    PubMed

    Vieira, G E G; Romeiro, G A; Sella, S M; Damasceno, R N; Pereira, R G

    2009-02-01

    In this work low temperature conversion (LTC) process was applied in a dried sludge from a petrochemical industry wastewater treatment station located in Rio de Janeiro, Brazil. The process was performed in two modes: continuous and batch-scale. This process produced a pyrolysis oil (continuous 14%; batch-scale 40% yield); pyrolytic char (continuous 46%; batch-scale 56% yield); gas and water. Pyrolysis oil fraction was analyzed by gas chromatographic mass spectrometry (GCMS) and the main components identified were toluene, ethylbenzene, styrene, isopropyl benzene, alpha-methylstyrene, butanenitrile and 1,3- biphenyl propane. Metals content, sulfur content and calorific value have been determined for the pyrolysis oil fraction. The results showed that the pyrolysis oil obtained could be used for industrial purposes and/or as energetic matrix.

  5. Different effects of an extended photoperiod treatment on growth, gonadal function, and condition of hair coats in Thoroughbred yearlings reared under different climate conditions

    PubMed Central

    SUZUKI, Tsuyoshi; MIZUKAMI, Hirotoshi; NAMBO, Yasuo; ISHIMARU, Mutsuki; MIYATA, Kenji; AKIYAMA, Kentaro; KOROSUE, Kenji; NAITO, Hiroshi; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2016-01-01

    ABSTRACT One- to two-year-old Thoroughbred colts and fillies being reared in Miyazaki (warm climate) and Hidaka (cold climate), Japan, were administered extended photoperiod (EP) treatment between December 20 and the following April 10, and its effect on growth, endocrine changes, gonadal activation, and hair coat condition was investigated. In colts reared in Miyazaki, no effect of EP treatment was noted on the growth indices, including body weight (BW), height at withers (HW), girth, and cannon circumference (CC), whereas the BWs and CCs of fillies were significantly higher in the EP treatment group than the control. In Hidaka, the BWs and HWs of colts and HWs of fillies were significantly higher in the EP treatment group. Gonadal activation characterized by an increase in circulating hormone concentrations was earlier in the EP treatment group for fillies reared in Miyazaki [luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4), and estradiol-17β (E2)] and in colts (LH, testosterone, and E2) and fillies (LH, FSH, P4, and E2) reared in Hidaka. Regardless of sex and climate, prolactin was significantly higher in the EP treatment group, whereas insulin-like growth factor (IGF-I) was not. Initial ovulation occurred before April in more of the EP treatment group than the control regardless of the climate. Molting of the hair coat, examined in March, was advanced in the EP treatment group regardless of sex and climate. These results suggest that EP treatment may promote growth and gonadal activation in fillies reared in Miyazaki and in colts and fillies reared in Hidaka and that the effect may be mediated by prolactin. PMID:26858576

  6. Conversion of activated-sludge reactors to microbial fuel cells for wastewater treatment coupled to electricity generation.

    PubMed

    Yoshizawa, Tomoya; Miyahara, Morio; Kouzuma, Atsushi; Watanabe, Kazuya

    2014-11-01

    Wastewater can be treated in microbial fuel cells (MFCs) with the aid of microbes that oxidize organic compounds using anodes as electron acceptors. Previous studies have suggested the utility of cassette-electrode (CE) MFCs for wastewater treatment, in which rice paddy-field soil was used as the inoculum. The present study attempted to convert an activated-sludge (AS) reactor to CE-MFC and use aerobic sludge in the tank as the source of microbes. We used laboratory-scale (1 L in capacity) reactors that were initially operated in an AS mode to treat synthetic wastewater, containing starch, yeast extract, peptone, plant oil, and detergents. After the organics removal became stable, the aeration was terminated, and CEs were inserted to initiate an MFC-mode operation. It was demonstrated that the MFC-mode operation treated the wastewater at similar efficiencies to those observed in the AS-mode operation with COD-removal efficiencies of 75-80%, maximum power densities of 150-200 mW m(-2) and Coulombic efficiencies of 20-30%. These values were similar to those of CE-MFC inoculated with the soil. Anode microbial communities were analyzed by pyrotag sequencing of 16S rRNA gene PCR amplicons. Comparative analyses revealed that anode communities enriched from the aerobic sludge were largely different from those from the soil, suggesting that similar reactor performances can be supported by different community structures. The study demonstrates that it is possible to construct wastewater-treatment MFCs by inserting CEs into water-treatment tanks. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Tantalum oxide-based plasma-sprayed environmental barrier coatings

    NASA Astrophysics Data System (ADS)

    Weyant, Christopher M.

    Energy efficiency in gas turbine engines is linked to the high temperature capabilities of materials used in the hot section of the engine. To facilitate a significant increase in engine efficiency, tough structural ceramics have been developed that can handle the thermo-mechanical stresses that gas turbine components experience. Unfortunately, the high-temperature, high-pressure, and high-velocity combustion gases in a gas turbine contain water vapor and/or hydrogen which have been shown to volatilize the protective silica layer on silicon-based ceramics. This degradation leads to significant surface recession in ceramic gas turbine components. In order to maintain their structural integrity, an environmental barrier coating (EBC) could be used to protect ceramics from the harsh gas turbine environment. Due to its coefficient of thermal expansion and phase stability at elevated temperatures, tantalum oxide (Ta2O5) was examined as the base material for an air plasma-sprayed EBC on Si3N 4 ceramics. As-sprayed pure Ta2O5 was comprised of both low-temperature beta-Ta2O5 and high-temperature alpha-Ta 2O5 that was quenched into the structure. Residual stress measurements via X-ray diffraction determined the as-sprayed coating to be in tension and extensive vertical macrocracks were observed in the coating. Heat treatments of the pure coating led to conversion of alpha-Ta2 O5 to beta-Ta2O5, conversion of tensile stresses to compressive, localized buckling of the coating, and significant grain growth which caused microcracking in the coating. The pure coating was found to be an inadequate EBC. Al2O3 was investigated as a solid solution alloying addition designed to enhance the stability of beta-Ta2O 5, and reduce grain growth by slowing grain boundary diffusion. La 2O3 was investigated as an alloying addition designed to form second phase particles which would reduce grain growth through pinning. Al2O3 was successful at both stabilizing beta-Ta 2O5 and reducing grain

  8. Porcelain-coated antenna for radio-frequency driven plasma source

    DOEpatents

    Leung, K.N.; Wells, R.P.; Craven, G.E.

    1996-12-24

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ions because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile. 8 figs.

  9. Porcelain-coated antenna for radio-frequency driven plasma source

    DOEpatents

    Leung, Ka-Ngo; Wells, Russell P.; Craven, Glen E.

    1996-01-01

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ion because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile.

  10. Morphology-preserving chemical conversion of bioorganic and inorganic templates

    NASA Astrophysics Data System (ADS)

    Vernon, Jonathan Paul

    The generation of nanostructured assemblies with complex (three-dimensional, 3D) self-assembled morphologies and with complex (multicomponent) tailorable inorganic compositions is of considerable technological and scientific interest. This dissertation demonstrates self-assembled 3D organic templates of biogenic origin can be converted into replicas comprised of numerous other functional nanocrystalline inorganic materials. Nature provides a spectacular variety of biologically-assembled 3D organic structures with intricate, hierarchical (macro-to-micro-to-nanoscale) morphologies. Such processing on readily-available structurally complex templates provides a framework for chemical conversion of synthetic organic templates and, potentially, production of organic/inorganic composites. Four specific research thrusts are detailed in this document. First, chemical conversion of a nanostructured bioorganic template into a multicomponent oxide compound (tetragonal BaTiO3) via SSG coating and subsequent morphology-preserving microwave hydrothermal processing is demonstrated. Second, morphology-preserving chemical conversion of bioorganic templates into hierarchical photoluminescent microparticles is demonstrated to reveal both the dramatic change in properties such processing can provide, and the potential utility of chemically transformed templates in anti-counterfeiting / authentication applications. Third, determination of the reaction mechanism(s) for morphology-preserving microwave hydrothermal conversion of TiO2 to BaTiO3, through Au inert markers on single crystal rutile titania, is detailed. Finally, utilization of constructive coating techniques (SSG) and moderate temperature (< 500°C) heat treatments to modify and replicate structural color is coupled with deconstructive focused ion beam microsurgery to prepare samples for microscale structure interrogation. Specifically, the effects of coating thickness and composition on reflection spectra of structurally

  11. Conversion to Paradoxical Finding on Technetium-99m-labeled RBC Scintigraphy after Treatment for Secondary Raynaud's Phenomenon.

    PubMed

    Chong, Ari; Ha, Jung-Min; Song, Ho-Chun; Kim, Jahae; Choi, Soo Jin Na

    2013-12-01

    An 18-year-old woman reported that after exposure to cold temperatures her fingers appeared blue and her hands and feet felt cold. Secondary Raynaud's phenomenon (RP) associated with peripheral vascular disease was suspected. Technetium (Tc)-99m-labeled RBC hand scintigraphy after cold change showed decreased blood pool activity in her fingers. The patient's symptoms improved after she received sarpogrelate HCL (200 mg/day) and nifedifine (40 mg/day). Follow-up scintigraphy performed 7 months after the patient started treatment showed paradoxically increased blood pool activity in her fingers after cold challenge. To the best of our knowledge, this is the first case report of a patient with secondary RP showing paradoxical change on scintigraphy after she received medication that improved her symptoms.

  12. Hydrothermal treatment and enzymatic hydrolysis of Tamarix ramosissima: evaluation of the process as a conversion method in a biorefinery concept.

    PubMed

    Xiao, Ling-Ping; Shi, Zheng-Jun; Xu, Feng; Sun, Run-Cang

    2013-05-01

    The present work investigated the effects of hydrothermal treatment (HTT) of Tamarix ramosissima by determination of sugar and inhibitor formation in the liquid fraction, and chemical and morphological changes of the pretreated solid material coupled with an evaluation of enzymatic hydrolysis. HTT was carried out in a batch reactor system at a maximal temperature (TMAX 180-240 °C) and evaluated for severities logRo ranging from 2.40 to 4.17. The liquid fractions were analyzed by HPLC, GPC, and GC-MS. The morphology and composition of the solid residues were characterized using an array of techniques, such as SEM, XRD, BET surface area, and CP/MAS (13)C NMR. Using a variety of tools, we have developed a better understanding of how HTT process affects biomass structure and cellulose properties that impact on its digestibility. These results provided