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Sample records for hot-dip batch galvanizing

  1. Hot-Dip Galvanized Sheet Production and Application

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Hot-dip galvanized sheet is wildly used in construction, household appliances, ship, vehicle and vessel building and machinery, etc. In last ten years, with the development of automobile industry, the anti-corrosion requirements for car body are increasingly strict, by which the rapid development in technology has been promoted. The application of hot-dip galvanized sheet, technological progress in production and some Chinese large units were introduced.

  2. Processing hot-dip galvanized AHSS grades: a challenging task

    Energy Technology Data Exchange (ETDEWEB)

    Pichler, A.; Hebesberger, T.; Tragl, E.; Traint, S.; Faderl, J.; Angeli, G.; Koesters, K. [voestalpine Stahl GmbH, Linz (Austria)

    2005-07-01

    High-strength thin sheet steel grades have gained a considerable market share. At present a very strong demand has been observed for DP (dual-phase), CP (complex phase) and TRIP grades, which are often summarized as advanced high-strength steel grades (AHSS). The potential benefits of applying AHSS grades were impressively demonstrated in the ULSAC-AVC project, in which a remarkable reduction in mass and an increase in stiffness and crash safety were achieved by using a very high share of AHSS steel grades. The present contribution concentrates on hot-dip galvanized AHSS thin sheet grades. The hot-dip galvanizeability of such grades is critically discussed after an overview is provided of the metallurgy of AHSS grades, including microstructure, mechanical properties, phase transformations and required alloy design. Based on these fundamentals, the processing of AHSS grades in the hot-dip galvanizing line is discussed and the resulting properties presented. (orig.)

  3. Development of Hot Dip Galvanized Steel Strip and Its Application in Automobile Industry

    Institute of Scientific and Technical Information of China (English)

    BIAN Jun; ZHU Yun; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    Hot dip galvanized product is widely used in architecture, household electric appliance, ship vehicle, vessel, mechano-electronic device and other fields including clothing, food, housing, and travel. The history, development, market need, and technological advancement of hot dip galvanized strip, production situation, and development tendency in China are briefly introduced. The fact that it is necessary to build new and auto galvanized strip line with the development of the iron and steel industry in China.

  4. The Microstructure and Hardness of Hot Dip Galvanized Steel During Wire Drawing

    Science.gov (United States)

    Klinaku, Shukri; Dilo, Teuta; Syla, Naim

    2010-01-01

    The steel wire samples are hot-dip-galvanized. The zinc coating is preformed using the standard method. To recognize the behavior of the zinc coated steel wire during the submission to deformation, the wire samples are drawn on a machine designed for this aim and then investigated. In this research is represented the phase structure of the zinc coated samples. Afterwards the thickness of the layer and the hardness of the hot-dip galvanized steel depending on the drawing is represented.

  5. The adhesion of epoxy cataphoretic coating on phosphatized hot-dip galvanized steel

    Directory of Open Access Journals (Sweden)

    Bajat Jelena B.

    2006-01-01

    Full Text Available The influence of hot-dip galvanized steel surface pretreatment on the adhesion of epoxy cataphoretic coating was investigated. Phosphate coatings were deposited on hot-dip galvanized steel and the influence of fluoride ions in the phosphating plating bath, as well as the deposition temperature of the plating bath, were investigated. The dry and wet adhesion of epoxy coating were measured by a standard pull-off method. The surface roughness of phosphatized galvanized steel was determined, as well as the wettability of the metal surface by emulsion of the epoxy resin in water. The adhesion of epoxy coatings on phosphatized hot-dip galvanized steel was investigated in 3wt.%NaCI.

  6. CORROSION RESISTANCE OF HOT DIP GALVANIZED STEEL PRETREATED WITH BIS-FUNCTIONAL SILANES MODIFIED WITH NANOALUMINA

    Institute of Scientific and Technical Information of China (English)

    F.J.Shan; C.S.Liu; S.H.Wang; G.C.Qi

    2008-01-01

    The corrosion behavior of hot dip galvanized steel pretreated with bis-[triethoxy-silylpropyl]tetrasulfide (BTESPT) modified with alumina particles was studied.The corrosion resistance of the passiving films was evaluated by Tafel polarization curve and electrochemical impedance spectroscopy.The films formed on the galvanized steel substrate were characterized by Fourier transform infrared spectroscopy and energy dispersive X-ray spectrometry.The surface morphology of the treated hot dip galva-nized steel samples was observed by Field Emission Scanning Electron Microscope. The results show that the pretreatments on the basis of silane films modified with nanoalumina particles have reduced both anodic and cathodic current densities,and increased total impedance in the measured frequency,consequently,improving cor-rosion protection for hot dip galvanized steel during immersion in NaCl solutions compared to chromate films and silane films.

  7. MICROSTRUCTURE AND PROPERTIES OF DEEP CROGENIC TREATMENT ELECTRODES FOR SPOT WELDING HOT DIP GALVANIZED STEEL

    Institute of Scientific and Technical Information of China (English)

    Wu Zhisheng; Liu Cuirong; Wang Jiuhai; Shan Ping; Hu Shengsun; Lian Jinrui

    2005-01-01

    The microstructure and elements distribution of the deep cryogenic treatment electrodes and non-cryogenic treatment electrodes for spot welding hot dip galvanized steel are observed by a scanning electrical microscope. The grain sizes, the resistivity and the hardness of the electrodes before and after deep cryogenic treatment are measured by X-ray diffraction, the DC double arms bridge and the Brinell hardness testing unit respectively. The spot welding process performance of hot dip galvanized steel plate is tested and the relationship between microstructure and physical properties of deep cryogenic treatment electrodes is analyzed. The experimental results show that deep cryogenic treatment makes Cr, Zr in deep cryogenic treatment electrodes emanate dispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non-cryogenic treatment ones so that the electrical conductivity and the thermal conductivity of deep cryogenic treatment electrodes are improved very much, which make spot welding process performance of the hot dip galvanized steel be improved.

  8. Effect of hot dip galvanized coating on the corrosion resistance of the external surface of reinforcement steel

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Oezlem; Topuz, Polat [Gedik University Vocational School, Istanbul (Turkey)

    2016-02-01

    Studies have been carried out to investigate the performance of hot dip galvanized coating on reinforcement corrosion. The coated and uncoated concrete specimens were subjected to accelerated corrosion to determine the time to corrosion initiation. The accelerated corrosion test results clearly showed that the specimens with hot dip galvanized coatings performed very well against reinforcement corrosion and were better than uncoated specimens.

  9. Relation between microstructure and adhesion of hot dip galvanized zinc coatings on dual phase steel

    NARCIS (Netherlands)

    Song, G. M.; Vystavel, T.; De Hosson, J. Th M.; Sloof, W. G.; van der Pers, N.M.

    The microstructure of hot dip galvanized zinc coatings on dual phase steel was investigated by electron microscopy and the coating adhesion characterized by tensile testing. The zinc coating consists of a zinc layer and columnar zeta-FeZn13 particles on top of a thin inhibition layer adjacent to the

  10. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    Science.gov (United States)

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-05-01

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry1,2,3. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago1. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear. First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test. All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  11. COMPARATIVE STUDY OF THE CORROSION BEHAVIOR OF HOT DIP GALVANIZED, GALVANNEAL AND GALVALUME COATED STEELS

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    Álvaro Pritzel dos Santos

    2013-10-01

    Full Text Available Corrosion attack of Hot Dip Zn coatings on steels is comparatively studied. For this, the electrochemical behavior of the coatings hot dip galvanized (GI, galvanneal (GA and galvalume (Zn55Al are analyzed in chloride solutions by cyclic voltammetry and by Scanning Vibrating Electrode Technique, with and without the incidence of white light. Coatings were characterized by Scanning Electronic Microscopy and Energy Dispersive X-Ray Spectrometry. The results show that the incidence of white UV-VIS light has a minor influence on the corrosive process, although the coatings contain intermetallic phases with semiconductor nature. The tests show that among the three coatings, GA has the slowest dissolution rate, when in contact with the steel for high exposed areas of steel.

  12. Nanoscale surface analysis on second generation advanced high strength steel after hot dip galvanizing.

    Science.gov (United States)

    Arndt, M; Duchoslav, J; Preis, K; Samek, L; Stifter, D

    2013-09-01

    Second generation advanced high strength steel is one promising material of choice for modern automotive structural parts because of its outstanding maximal elongation and tensile strength. Nonetheless there is still a lack of corrosion protection for this material due to the fact that cost efficient hot dip galvanizing cannot be applied. The reason for the insufficient coatability with zinc is found in the segregation of manganese to the surface during annealing and the formation of manganese oxides prior coating. This work analyses the structure and chemical composition of the surface oxides on so called nano-TWIP (twinning induced plasticity) steel on the nanoscopic scale after hot dip galvanizing in a simulator with employed analytical methods comprising scanning Auger electron spectroscopy (SAES), energy dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) for cross section preparation. By the combination of these methods, it was possible to obtain detailed chemical images serving a better understanding which processes exactly occur on the surface of this novel kind of steel and how to promote in the future for this material system galvanic protection.

  13. Dissolution-Induced Nanowire Synthesis on Hot-Dip Galvanized Surface in Supercritical Carbon Dioxide

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    Aaretti Kaleva

    2017-07-01

    Full Text Available In this study, we demonstrate a rapid treatment method for producing a needle-like nanowire structure on a hot-dip galvanized sheet at a temperature of 50 °C. The processing method involved only supercritical carbon dioxide and water to induce a reaction on the zinc surface, which resulted in growth of zinc hydroxycarbonate nanowires into flower-like shapes. This artificial patina nanostructure predicts high surface area and offers interesting opportunities for its use in industrial high-end applications. The nanowires can significantly improve paint adhesion and promote electrochemical stability for organic coatings, or be converted to ZnO nanostructures by calcining to be used in various semiconductor applications.

  14. Influence of Air-Knife Wiping on Coating Thickness in Hot-Dip Galvanizing

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; CUI Qi-peng; SHAO Fu-qun; WANG Jun-sheng; ZHAO Hong-yang

    2012-01-01

    In hot-dip galvanizing process, air jet wiping control is so crucial to decide the coating thickness and uni- formity of the zinc layer on the steel strip. The mathematical models developed predict the zinc coating thickness as a function of pressure and shear stress. The required pressure and shear stress profile on the strip surface were calcu- lated using regression analysis, and carried out using numerical simulation as FLUENT, a finite element analysis software. The influences of the outlet pressure, the nozzle to strip distance, the slot opening, the edge baffle plate, as well as the tilting angle of air knife were discussed. Combining with these results and regression analysis on the practical data, four first-order polynomial multi-parameter models were established for different targeted coating thicknesses with better regression coefficients. The validated model was used to carry out sensitivity analysis to de- termine the favorable controlling regime for the air jet wiping process.

  15. Mössbauer and XRD study of hot dip galvanized alloy

    Science.gov (United States)

    Kuzmann, E.; Speakman, R.; El-Sharif, M.; Stichleutner, S.; Homonnay, Z.; Klencsár, Z.; Sziráki, L.; Chisholm, C. U.; Lak, Gy. B.

    2016-12-01

    Mössbauer spectroscopy has been used to investigate the nature of the Zinc-Iron alloys present within the Hot Dip Galvanized (HDG) layers of steel with a silicon content of 0.35 %. The investigation also studied the impact of the powder coating pretreatment on the nature of the alloy layers. The acid etching process within the pretreatment process in particular would be expected to have a significant impact on the HDG layer. This study utilized 57Fe Mössbauer spectroscopy to examine identically processed samples prior to and post pre treatment. XRD and 57Fe CEMS measurements were performed on hot galvanized S355J2 + N samples, forming sandwiched structure. Both XRD and CEMS reveal the presence of dominant steel phase in accordance with its estimated occurrence on the surface of the sandwiched samples. Minor Γ-Fe3Zn10, ζ-FeZn15 and solid solution Fe-Zn as well as minor Fe-Si phases could also be identified.

  16. Performance of Flow and Heat Transfer in a Hot-Dip Round Coreless Galvanizing Bath

    Science.gov (United States)

    Yue, Qiang; Zhang, Chengbo; Xu, Yong; Zhou, Li; Kong, Hui; Wang, Jia

    2017-04-01

    Flow field in a coreless hot-dip galvanizing pot was investigated through a water modeling experiment. The corresponding velocity vector was measured using an acoustic Doppler velocimeter. The flow field of molten zinc in the bath was also analyzed. Steel strip velocities from 1.7 to 2.7 m/s were adopted to determine the effect of steel strip velocity on the molten zinc flow in the bath. A large vortex filled the space at the right side of the sink roll, under linear speed from 1.0 to 2.7 m/s and width from 1.0 to 1.3 m of the steel strip, because of the effects of wall and shear stress. The results of the water modeling experiment were compared with those of numerical simulations. In the simulation, Maxwell equations were solved using finite element method to obtain magnetic flux density, electromagnetic force, and Joule heating. The Joule heating rate reached the maximum and minimum values near the side wall and at the core of the bath, respectively, because of the effect of skin and proximity. In an industrial-sized model, the molten zinc flow and temperature fields driven by electromagnetic force and Joule heating in the inductor of a coreless galvanizing bath were numerically simulated. The results indicated that the direction of electromagnetic force concentrated at the center of the galvanizing pot horizontal planes and exerted a pinch effect on molten zinc. Consequently, molten zinc in the pot was stirred by electromagnetic force. Under molten zinc flow and electromagnetic force stirring, the temperature of the molten zinc became homogeneous throughout the bath. This study provides a basis for optimizing electromagnetic fields in coreless induction pot and fine-tuning the design of steel strip parameters.

  17. Performance of Flow and Heat Transfer in a Hot-Dip Round Coreless Galvanizing Bath

    Science.gov (United States)

    Yue, Qiang; Zhang, Chengbo; Xu, Yong; Zhou, Li; Kong, Hui; Wang, Jia

    2016-12-01

    Flow field in a coreless hot-dip galvanizing pot was investigated through a water modeling experiment. The corresponding velocity vector was measured using an acoustic Doppler velocimeter. The flow field of molten zinc in the bath was also analyzed. Steel strip velocities from 1.7 to 2.7 m/s were adopted to determine the effect of steel strip velocity on the molten zinc flow in the bath. A large vortex filled the space at the right side of the sink roll, under linear speed from 1.0 to 2.7 m/s and width from 1.0 to 1.3 m of the steel strip, because of the effects of wall and shear stress. The results of the water modeling experiment were compared with those of numerical simulations. In the simulation, Maxwell equations were solved using finite element method to obtain magnetic flux density, electromagnetic force, and Joule heating. The Joule heating rate reached the maximum and minimum values near the side wall and at the core of the bath, respectively, because of the effect of skin and proximity. In an industrial-sized model, the molten zinc flow and temperature fields driven by electromagnetic force and Joule heating in the inductor of a coreless galvanizing bath were numerically simulated. The results indicated that the direction of electromagnetic force concentrated at the center of the galvanizing pot horizontal planes and exerted a pinch effect on molten zinc. Consequently, molten zinc in the pot was stirred by electromagnetic force. Under molten zinc flow and electromagnetic force stirring, the temperature of the molten zinc became homogeneous throughout the bath. This study provides a basis for optimizing electromagnetic fields in coreless induction pot and fine-tuning the design of steel strip parameters.

  18. Identification and preliminary evaluation of polychlorinated naphthalene emissions from hot dip galvanizing plants.

    Science.gov (United States)

    Liu, Guorui; Lv, Pu; Jiang, Xiaoxu; Nie, Zhiqiang; Liu, Wenbin; Zheng, Minghui

    2015-01-01

    Hot dip galvanizing (HDG) processes are sources of polychlorinated-p-dioxins and dibenzofurans (PCDD/Fs). Close correlations have been found between the concentration of PCDD/Fs and polychlorinated naphthalenes (PCNs) that are produced and released during industrial thermal processes. We speculated, therefore, that HDG plants are potential PCN sources. In this preliminary study, PCNs were analyzed in solid residues, ash and precipitate from three HDG plants of different sizes. The total PCN concentrations (∑2-8PCNs) in the residue samples ranged from 60.3 to 226pgg(-1). The PCN emission factors for the combined ash and precipitate residues from the HDG plants ranged from 75 to 178ngt(-1) for the dichlorinated and octachlorinated naphthalenes. The preliminary results suggested that the HDG industry might not currently be a significant source of PCN emissions. The trichloronaphthalenes were the dominant homologs followed by the dichloronaphthalenes and the tetrachloronaphthalenes. The PCN congeners CN37/33/34, CN52/60, CN66/67, and CN73 dominated the tetrachlorinated, pentachlorinated, hexachlorinated, and heptachlorinated naphthalene homologs, respectively. The PCNs emitted from the HDG plants had similar homolog distributions and congener profiles to the PCNs emitted from combustion plants and other metallurgical processes. The identification and preliminary evaluation of PCN emissions from HDG plants presented here will help in the prioritization of measures for controlling PCN emissions from industrial sources.

  19. Growth and corrosion behavior of molybdate passivation film on hot dip galvanized steel

    Institute of Scientific and Technical Information of China (English)

    卢锦堂; 孔纲; 陈锦虹; 许乔瑜; 眭润舟

    2003-01-01

    Hot dip galvanized steel sheets were passivated by molybdate aqueous solution containing 10 g/LNa2 MoO4 @ 2H2O, and the growth behavior and corrosion resistance of the passivation film were investigated. Inthe initial stage of passivation, the mass gain of film increases with passivation time proportionally. The film growsup more quickly and is apt to cracking at grain boundaries of zinc, then the cracks spread gradually on the whole sur-face of the film, and eventually the film will flake off with the increasing of film thickness. XPS results indicate thatMo compounds are present in Mo(Ⅵ) state on the surface of the film, and Mo(Ⅵ) and Mo(Ⅳ ) states inside thefilm. NSS test shows that, the corrosion resistance of the passivation film decreases as the cracks occur, but inAASS test, the thicker the film is, the better the corrosion resistance is, the cracks of film have little effect on thecorrosion resistance.

  20. Experimental analysis and theoretical predictions of the limit strains of a hot-dip galvanized interstitial-free steel sheet

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    Maria Carolina dos Santos Freitas

    2013-04-01

    Full Text Available In this work, the formability of a hot-dip galvanized interstitial-free (IF steel sheet was evaluated by means of uniaxial tensile and Forming Limit Curve (FLC tests. The FLC was defined using the flat-bottomed Marciniak's punch technique, where the strain analysis was made using a digital image correlation software. A plastic localization model was also proposed wherein the governing equations are solved with the help of the Newton's method. The investigated hot-dip galvanized IF steel sheet presented a very good formability level in the deep-drawing range consistent with the measured Lankford values. The predicted limit strains were found to be in good agreement with the experimental data of the hot-dip galvanized IF steel sheet owing to the definition of the localization model geometrical imperfection as a function of the experimental surface roughness evolution and, in particular, to the yield surface flattening near to the plane-strain stress state authorized by the adopted yield criterion.

  1. Growth and corrosion resistance of molybdate modified zinc phosphate conversion coatings on hot-dip galvanized steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The modified zinc phosphate conversion coatings(ZPC) were formed on hot-dip galvanized(HDG) steel when 1.0 g/L sodium molybdate were added in a traditional zinc phosphate solution. The growth performance and corrosion resistance of the modified ZPC were investigated by SEM, open circuit potential(OCP), mass gain, potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) measurements and compared with those of the traditional ZPC. The results show that if sodium molybdate is added in a traditional zinc phosphate solution, the nucleation of zinc phosphate crystals is increased obviously; zinc phosphate crystals are changed from bulky acicular to fine flake and a more compact ZPC is obtained. Moreover, the mass gain and coverage of the modified ZPC are also boosted. The corrosion resistance of ZPI is increased with an increase in coverage, and thus the corrosion protection ability of the modified ZPC for HDG steel is more outstanding than that of the traditional ZPC.

  2. Characterization of solid wastes from two different hot-dip galvanizing processes; Caracterizacion de residuos solidos procedentes de dos procesos distintos de galvanizado en caliente por inmersion

    Energy Technology Data Exchange (ETDEWEB)

    Delvasto, P.; Casal-Ramos, J. a.; Gonzalez-Jordan, O.; Duran-Rodriguez, N. C.; Dominguez, J. R.; Moncada, P.

    2012-11-01

    Zinc dust and zinc ash from hot-dip galvanizing industries located in Venezuela were characterized using atomic spectroscopy, scanning electron microscopy, X-Ray diffraction and infrared spectroscopy. Dust was formed during the high-pressure drying process of the galvanized pieces, in a plant that uses a steel kettle to hold the molten zinc. Ash identified as A came from the same plant as the dust, while ash identified as B came from a hot-dip galvanizing plant which use a ceramic lined galvanizing furnace. Dust contained 98 wt % Zn, in metallic form. Both ash samples contained: Zn and ZnO, while Zn{sub 5}(OH){sub 8}Cl{sub 2}×H{sub 2}O and ZnCl{sub 2} were only found in ash B. Globally, ash “A” and ash “B” contain 71 and 75 wt % Zn, respectively. (Author)

  3. Effect of Chromium on Microstructure and Mechanical Properties of Cold Rolled Hot-dip Galvanizing DP450 Steel

    Institute of Scientific and Technical Information of China (English)

    Yun HAN; Shuang KUANG; Hua-sai LIU; Ying-hua JIANG; Guang-hui LIU

    2015-01-01

    Two cold rolled hot-dip galvanizing dual phase (DP) 450 steels with different amounts of chromium were designed and the effects of the chromium concentration and galvanizing processes on the microstructure and mechanical properties were also investigated. The results show that the experimental steels exhibit typical dual phase microstructure character. However, the ferrite phase of steel with higher chromium is more regular and its boundaries are clearer. Meanwhile, martensite austenite (MA) island in steel No. 2 is diffused and no longer distributes along the grain boundary as net or chain shape. More MA islands enriched with Cr element can be found in the ferrite grains, and the increment of Cr element improves the stablity of the austenite so that the austenite has been reserved in MA islands. In addition, the experimental steel with higher chromium exhibits better elongation, lower yield ratio and better formability. The mean hole expanding ratio of steels No. 1 and No. 2 is 161.70% and 192.70%, respectively.

  4. The effect of zinc bath temperature on the morphology, texture and corrosion behaviour of industrially produced hot-dip galvanized coatings

    Directory of Open Access Journals (Sweden)

    A. Bakhtiari

    2014-03-01

    Full Text Available The purpose of this work is to identify the influence of zinc bath temperature on the morphology, texture and corrosion behavior of hot-dip galvanized coatings. Hot-dip galvanized samples were prepared at temperature in the range of 450-480 °C in steps of 10 °C, which is the conventional galvanizing temperature range in the galvanizing industries. The morphology of coatings was examined with optical microscopy and scanning electron microscopy (SEM. The composition of the coating layers was determined using energy dispersive spectroscopy (EDS analysis. The texture of the coatings was evaluated using X-ray diffraction. Corrosion behavior was performed using salt spray cabinet test and Tafel extrapolation test. From the experimental results, it was found that increasing the zinc bath temperature affects the morphology of the galvanized coatings provoking the appearance of cracks in the coating structure. These cracks prevent formation of a compact structure. In addition, it was concluded that (00.2 basal plane texture component was weakened by increasing the zinc bath temperature and, conversely, appearance of (10.1 prism component, (20.1 high angle pyramidal component and low angle component prevailed. Besides, coatings with strong (00.2 texture component and weaker (20.1 components have better corrosion resistance than the coatings with weak (00.2 and strong (20.1 texture components. Furthermore, corrosion resistance of the galvanized coatings was decreased by increasing the zinc bath temperature.

  5. Effect of Immersion Time and Cooling Mode on the Electrochemical Behavior of Hot-Dip Galvanized Steel in Sulfuric Acid Medium

    Science.gov (United States)

    Lekbir, Choukri; Dahoun, Nessrine; Guetitech, Asma; Hacid, Abdenour; Ziouche, Aicha; Ouaad, Kamel; Djadoun, Amar

    2017-04-01

    In this work, we investigated the influence of galvanizing immersion time and cooling modes environments on the electrochemical corrosion behavior of hot-dip galvanized steel, in 1 M sulfuric acid electrolyte at room temperature using potentiodynamic polarization technique. In addition, the evolution of thickness, structure and microstructure of zinc coatings for different immersion times and two cooling modes (air and water) is characterized, respectively, by using of Elcometer scan probe, x-ray diffraction and metallography analysis. The analysis of the behavior of steel and galvanized steel, vis-a-vis corrosion, by means of corrosion characteristic parameters as anodic (β a) and cathodic (β c) Tafel slopes, corrosion potential (E corr), corrosion current density (i corr), corrosion rate (CR) and polarization resistance (R p), reveals that the galvanized steel has anticorrosion properties much better than that of steel. More the immersion time increases, more the zinc coatings thickness increases, and more these properties become better. The comparison between the two cooling modes shows that the coatings of zinc produced by hot-dip galvanization and air-cooled provides a much better protection to steel against corrosion than those cooled by quenching in water which exhibit a brittle corrosive behavior due to the presence of cracks.

  6. Influence of Minor Alloying Elements on Selective Oxidation and Reactive Wetting of CMnSi TRIP Steel during Hot Dip Galvanizing

    Science.gov (United States)

    Cho, Lawrence; Kim, Myung Soo; Kim, Young Ha; De Cooman, Bruno C.

    2014-09-01

    The influence of the addition of minor alloying elements on the selective oxidation and the reactive wetting of CMnSi transformation-induced plasticity (TRIP) steels was studied by means of galvanizing simulator tests. Five TRIP steels containing small alloying additions of Cr, Ni, Ti, Cu, and Sn were investigated. After intercritical annealing (IA) at 1093 K (820 °C) in a N2 + 5 pct H2 gas atmosphere with a dew point of 213 K (-60 °C), two types of oxides were formed on the strip surface: Mn-rich xMnO·SiO2 ( x > 1.5) and Si-rich xMnO·SiO2 ( x formation of the inhibition layer during the hot dip galvanizing. The addition of a small amount of Sn is shown to significantly decrease the density of Zn-coating defects on CMnSi TRIP steels.

  7. Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

    Science.gov (United States)

    Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

    2016-07-01

    The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

  8. Problems with reliability and safety of hot dip galvanized steel structures Problemas com a confiabilidade e segurança de estruturas de aço galvanizadas a quente

    Directory of Open Access Journals (Sweden)

    L. Mraz

    2009-06-01

    Full Text Available Hot dip galvanizing is very effective means of protection against corrosion. Some recommendation concerning the steel quality are generally known and accepted. The process consists of cleaning (pickling or sand blasting and dipping the structures or pieces into liquid zinc bath. The case study of hot dip galvanized steels is presented. Some recent failures of hot dip galvanized welded structures and hot dip galvanized high strength steel screws are presented. Structures were made of S355 grade steel and MIG/MAG process was applied for welding. Large cracks were observed in the vicinity of welds after hot dip galvanizing process. The presence of both hydrogen and liquid metal embrittlement was identified and associated mainly with higher hardness of HAZ or the quenched and tempered steels. Possible cracking mechanisms are discussed. The influence of chemical composition and production process (welding, heat treatment was analyzed according to data published in literature. The solutions and recommendations for avoiding the failure in hot dip galvanized structures are proposed.Galvanização a quente é um meio muito efetivo de proteção contra a corrosão. Recomendações relativas a qualidade do aço são geralmente conhecidas e aceitas. O processo consiste de limpar (decapagem ou jateamento e mergulhar as estruturas ou partes destas em um banho de zinco líquido. O presente trabalho apresenta casos de falhas recentes em estruturas soldadas e em parafusos de aços de alta resistência galvanizados a quente. As estruturas foram fabricadas com aço do grau S355 e o processo MIG/MAG foi usado para a soldagem. Os parafusos foram fabricados com aço de alto carbono. Grandes trincas foram observadas nas proximidades das soldas após o processo de galvanização a quente. A ocorrência de fragilização tanto por hidrogênio como por metal líquido foi identificada e associada com a dureza elevada tanto da ZTA como dos aços temperados e revenidos. Os

  9. Effect of Process Variables on the Grain Size and Crystallographic Texture of Hot-Dip Galvanized Coatings

    Science.gov (United States)

    Kaboli, Shirin; McDermid, Joseph R.

    2014-08-01

    A galvanizing simulator was used to determine the effect of galvanizing bath antimony (Sb) content, substrate surface roughness, and cooling rate on the microstructural development of metallic zinc coatings. Substrate surface roughness was varied through the use of relatively rough hot-rolled and relatively smooth bright-rolled steels, cooling rates were varied from 0.1 to 10 K/s, and bulk bath Sb levels were varied from 0 to 0.1 wt pct. In general, it was found that increasing bath Sb content resulted in coatings with a larger grain size and strongly promoted the development of coatings with the close-packed {0002} basal plane parallel to the substrate surface. Increasing substrate surface roughness tended to decrease the coating grain size and promoted a more random coating crystallographic texture, except in the case of the highest Sb content bath (0.1 wt pct Sb), where substrate roughness had no significant effect on grain size except at higher cooling rates (10 K/s). Increased cooling rates tended to decrease the coating grain size and promote the {0002} basal orientation. Calculations showed that increasing the bath Sb content from 0 to 0.1 wt pct Sb increased the dendrite tip growth velocity from 0.06 to 0.11 cm/s by decreasing the solid-liquid interface surface energy from 0.77 to 0.45 J/m2. Increased dendrite tip velocity only partially explains the formation of larger zinc grains at higher Sb levels. It was also found that the classic nucleation theory cannot completely explain the present experimental observations, particularly the effect of increasing the bath Sb, where the classical theory predicts increased nucleation and a finer grain size. In this case, the "poisoning" theory of nucleation sites by segregated Sb may provide a partial explanation. However, any analysis is greatly hampered by the lack of fundamental thermodynamic information such as partition coefficients and surface energies and by a lack of fundamental structural studies. Overall

  10. 带钢连续热镀锌层厚度控制技术的研究%A Research on Thickness Control Technology for Continuous Hot Dip Galvanized Zinc Layer on Strip Steel

    Institute of Scientific and Technical Information of China (English)

    郑永春; 岑耀东; 田荣彬

    2012-01-01

    Control of zinc layer thickness has been the key and difficulty in continuous hot dip galvanizing production for strip steel. According to the characteristics of DAK air knife, the effects of hot dip galvanizing production process and equipment on zinc layer thickness are analyzed, the main methods for controlling the thickness of zinc layer summarized, and the measures for improving the control precision of zinc layer proposed.%镀锌层厚度控制一直是带钢连续热镀锌生产的重点和难点.针对DAK气刀的特点,分析了热镀锌生产工艺和设备对镀锌层厚度的影响,总结了镀锌层厚度控制的主要方法,提出了提高镀锌层厚度控制精度的措施.

  11. Overall model of the dynamic behaviour of the steel strip in an annealing heating furnace on a hot-dip galvanizing line

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2010-10-01

    Full Text Available Predicting the temperature of the steel strip in the annealing process in a hot-dip galvanizing line (HDGL is important to ensure the physical properties of the processed material. The development of an accurate model that is capable of predicting the temperature the strip will reach according to the furnace’s variations in temperature and speed, its dimensions and the steel’s chemical properties, is a requirement that is being increasingly called for by industrial plants of this nature. This paper presents a comparative study made between several types of algorithms of Data Mining and Artificial Intelligence for the design of an efficient and overall prediction model that will allow determining the strip’s variation in temperature according to the physico-chemical specifications of the coils to be processed, and fluctuations in temperature and speed that are recorded within the annealing process. The ultimate goal is to find a model that is effectively applicable to coils of new types of steel or sizes that are being processed for the first time. This model renders it possible to fine-tune the control model in order to standardise the treatment in areas of the strip in which there is a transition between coils of different sizes or types of steel.La predicción de la temperatura de la banda de acero dentro del proceso de recocido de una planta de galvanizado continuo en caliente es importante para garantizar las propiedades físicas del material procesado. El desarrollo de un modelo preciso que sea capaz de predecir la temperatura que va a alcanzar la banda según las variaciones de temperaturas y velocidades del horno, y sus dimensiones y propiedades químicas del acero, es una necesidad cada vez más demandada por este tipo de plantas industriales. En el presente estudio se muestra una comparativa realizada entre diversos tipos de algoritmos deMinería de Datos e Inteligencia Artificial para el desarrollo de un modelo de predicci

  12. 连续退火热镀锌板镀层表面黑点缺陷研究%Study of dark dot defect on coating surface of continuously annealed hot-dip galvanized steel sheet

    Institute of Scientific and Technical Information of China (English)

    刘李斌; 蒋光锐; 马兵智; 李蔚然; 刘华赛; 齐春雨

    2014-01-01

    研究了热镀锌板镀层表面黑点的产生机理,分析了该缺陷对热镀锌板涂镀质量的影响,提出了相应的改进措施。结果表明,基板表面存在微小凹坑,镀锌后表面形成黑色圆形氧化膜,即黑点缺陷,对热镀锌板涂镀后的磷化膜质量产生不利影响。实际生产中,通过降低热轧卷的卷曲温度、清洗槽电解电流密度及提高退火炉的密封性,可有效减轻该缺陷。%Generation mechanism of dark dot defect and effect on painting surface quality of hot -dip galvanized steel sheet were studied , and some relative improvement measures were proposed .The results show that little pits exist on the substrate , which form dark dot defect is composed of oxide film after galvanized .The dark dot defect markedly influences crystal structure of phosphate coating .Moreover , during practical production , it could be effectively reduced by decreasing coiling temperature , reducing current density in rinse tank and improving sealing of the annealing furnace .

  13. 热镀锌张力辊电机气动抱闸系统的改造%Reformation of Pneumatic Brake System in Tension Roller Motor of Hot Dip Galvanized Steel

    Institute of Scientific and Technical Information of China (English)

    岑耀东; 陈林

    2012-01-01

    Against the problem of the tension roller brake system motor's frequent abnormal braking in the production line of hot dip galvanizing, the brake system s working principle and structural characteristics were analyzed. It is found that the main reasons causing this fault is failure of closing switches induction position, which result from the brake head bushings seal leakage. By improving the design and transformation of brake system's structure, the problem of the brake sensor is solved, and the resulting problem of abnormal downtime is avoided as well.%针对热镀锌生产线中张力辊电机抱闸系统频繁出现非正常制动故障的问题,从抱闸系统的工作原理和结构特点方面进行分析,发现抱闸头轴套密封处漏气造成接近开关感应位置失效是此故障的主要原因,采用铁片在外端固定接近开关来代替原来的密封盖后,解决了该故障问题.

  14. 锌浴中镍含量对热浸锌镀层厚度的影响%Effect of Ni Content in Zn Bath on Thickness of Hot Dip Galva-nized Coating

    Institute of Scientific and Technical Information of China (English)

    卢锦堂; 许乔瑜; 陈锦虹; 孔纲; 刘丽霞

    2001-01-01

    The effect of Ni content in Zn bath on thickness of hot dip galvanized coating was studied using SEM. It showed thatwith the Ni content increasingthe coating thickness increased when the nickel content 0.12%. The industrial practice showed that the Ni content can be chosen in a range of 0.04%~0.10%which results in satisfactory coating thickness and saves zinc because of reducing the excess coating thickness.%应用SEM、EPMA等方法研究了锌浴中镍含量对热浸锌镀层厚度的影响,试验结果表明:当锌浴中镍含量小于0.12% (wt)时,镀层随镍含量增加而减薄;当镍含量大于0.12%时,镀层则随镍含量增加而增厚。在热镀锌生产线上对0.10%以下的不同镍含量锌浴的应用结果表明:为了兼顾不同产品对最低镀层厚度的要求,镍含量可在0.04%~0.10%间选择,这时由于减少了镀层超厚,节锌效果明显。

  15. 热镀锌钢板表面硅烷膜的制备工艺与耐蚀性能%Preparation and Corrosion Resistance of Silane Film on Hot-dip Galvanized Steel

    Institute of Scientific and Technical Information of China (English)

    吴海江; 卢锦堂

    2009-01-01

    采用正交试验结合中性盐雾试验和极化曲线测定等方法,研究了热镀锌钢板表面的硅烷膜在制备过程中的硅烷体积分数、水解溶剂中甲醇体积分数、水解时间、水解温度、溶液PH值、浸涂时间等因素对硅烷膜耐蚀性能的影响,并确定了最佳成膜工艺,讨论了硅烷膜作用机理.结果表明:最佳成膜工艺为硅烷体积分数7%、溶液pH值4、水解溶剂中甲醇体积分数10%、水解温度40℃、水解时间6 h、浸涂时间120 s,采用该工艺制备硅烷膜可明显推迟热镀锌钢板出现白锈的时间;硅烷膜同时也抑制了热镀锌钢板在腐蚀过程中阳极和阴极的反应,显著改善了热镀锌钢板的耐蚀性能.%A nontoxic silanized treatment process for hot-dip galvanized steel was investigated by the orthogonal experiment. The protection of silane films on galvanized steel surface was evaluated by neutral salt spray test and polarization test. The factors affecting the corrosion resistance of silane films were discussed, including concentration of silane solution, concentration of methanol, hydrolysis time, hydrolysis temperature, pH of silane solution and immersion time. The optimum technological parameters were obtained, and the mechanism was analyzed. The results show that the silane films had the optimum anti-corrosion properties under the conditions of concentration of the silane solution 7%, concentration of methanol in hydrolysis solvents 10%, hydrolysis time 6 h, hydrolysis temperature 40 ℃, pH of the silane solution 4 and immersion time 120 s acted as a physical barrier of galvanized steel and suppressed both cathodic and anodic reactions of corrosion simultaneously. The time of white rust occurence on galvanized coating was delayed. The silane films obtained excellent corrosion resistance under the optimum technological conditions.

  16. Preparation and Corrosion Resistance Evaluation of Cerium Salt/Silane Composite Coating on Hot-Dip Galvanized Steel%热镀锌钢铈盐/硅烷复合膜的制备及其耐蚀性能

    Institute of Scientific and Technical Information of China (English)

    吴海江; 徐国荣; 许剑光; 徐红梅; 吴玉蓉; 颜焕元

    2013-01-01

    热镀锌钢板上单一的铈盐、硅烷钝化膜有一些缺点,对提高其耐蚀性作用不大.为此,将热镀锌钢板先经铈盐溶液处理,再用乙烯基三甲氧基硅烷溶液浸渍,获得了铈盐/硅烷复合钝化膜.采用扫描电镜(SEM)、俄歇电子能谱(AES)、盐水全浸试验和电化学交流阻抗谱(EIS)研究了复合膜层的表面形貌、结构特性和耐蚀性能.结果表明:硅烷膜能较好地填充铈盐转化膜中的裂纹,铈盐/硅烷复合膜层连续、完整、致密,厚400~450 nm,与基体结合较好,复合膜中硅烷膜/铈盐转化膜/锌基体的化学成分呈连续的梯度变化;与热镀锌钢相比,单一铈盐转化膜、硅烷膜的交流阻抗值增加了1个多数量级,复合膜的则增加了约2个数量级,复合膜层的耐蚀性较单一膜层显著增强,且优于常规铬酸盐钝化膜.%Hot-dip galvanized steel was firstly treated in the solution of cerium nitrate and then immersed in vinyltrimethoxysilane solution to obtain composite coating consisting of cerium salt coating and silane coating. The morphology and microstructure of as - obtained composite coating were analyzed by scanning electron microscopy and Auger elec tron spectroscopy, and its corrosion resistance was evaluated based on immersion test in salt water and electrochemical imped ance spectroscopic analysis as well. Results showed that the mi- crocracks in the cerium conversion coating could be well filled up with the silane coating. As-obtained cerium salt/silane composite coating with a thickness of 400 ~ 450 nm was continuous, com plete and compact, and had good adhesion to the steel substrate as well as gradient chemical composition. In the meantime, the electrochemical impedance values of the cerium conversion coat ing and silane coating were increased by more than one order of magnitude as compared with that of hot-dip galvanized steel sub strate, and the electrochemical impedance value of the cerium salt

  17. Corrosion resistance of silane/silicate composite films on hot-dip galvanized steel%热镀锌钢表面硅烷/硅酸盐复合膜的耐蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    吴海江; 卢锦堂

    2009-01-01

    To improve the corrosion resistance of silane films further, the silane/silicate composite films were prepared by immersion hot-dip galvanized (HDG) steel samples in silane solution firstly and then in sodium silicate solution. The corrosion resistance of the composite films were investigated by neutral salt spray (NSS)test, humid thermic test, salt water test and electrochemical impedance spectroscopy (EIS). The results revealed that the corrosion resistance of the composite films was significantly enhanced, which was superior to the single silane film, even better than some chromate passivation film. Furthermore, the low frequency inductive loop in EIS was disappeared and the low frequency impedance values for the composite films in 5% NaCl solution were firstly increased then decreased with the increasing of the immersion time, which demonstrated the self-healing activity of the composite films.%为了改善硅烷膜的耐蚀性,将硅烷化热镀锌钢板用硅酸钠溶液封闭后处理,获得了硅烷/硅酸盐复合膜.采用中性盐雾试验(NSS)、湿热试验、盐水全浸试验和电化学交流阻抗谱(EIS)评价了膜层的耐蚀性能.结果表明,与单一硅烷膜相比,复合膜的耐蚀性能明显提高,超过了常规铬酸盐钝化膜.尤其是在5%NaCl溶液中,复合膜的低频阻抗数值随浸泡时间的增加先增大后减小,表明其具有一定的"自修复"能力.

  18. Improving the Tensile Strength of B82 MnQL Materials by Hot Dip Galvanizing%热镀锌法提高B82 MnQL材料的抗拉强度研究

    Institute of Scientific and Technical Information of China (English)

    曾凡勇; 李养良; 张德勤; 李海洲; 潘东; 倪晓峰

    2016-01-01

    目的:增强B82 MnQL材料的抗拉强度。方法以B82 MnQL盘条作为热镀锌的试验材料,利用拉伸试验机、反复弯曲试验机对其力学性能进行测试,借助金相显微镜、扫描电镜分析几种镀锌工艺下的横截面和轴向截面以及拉拔断口的组织形貌,同时测试显微硬度。结果 B82 MnQL盘条拉拔后钢丝的抗拉强度由原来的1250 MPa提高至1670 MPa。断面收缩率由32.5%下降至7%。采用新镀锌工艺和助镀配方,B82MnQL钢丝镀锌后抗拉强度下降幅度为8%,低于传统的10%~15%。稳定化后B82MnQL的扭转次数为20次左右,反复弯曲次数为6次左右,强度由1650 MPa提高至1710 MPa,硬度值比镀锌后有较大提高,由镀锌后的430HV升高至450HV,而且分布均匀。结论通过优化镀锌工艺,能大幅提高B82 MnQL盘条的抗拉强度。%ABSTRACT:Objective To enhance the tensile strength of the B82MnQL material. Methods The B82MnQL wire rod was used as the material for hot dip galvanizing experiment, and its mechanical properties were tested using tensile testing machine and repeated bending testing machine. The microstructures of the cross section, the axial section and the drawing fracture were analyzed by means of optical microscopy and scanning electron microscopy. Results The tensile strength of the B82MnQL wire rod after drawing was increased from 1250 MPa to 1670 MPa. The shrinkage rate of the cross section was decreased from 32. 5% to 7%. Using the new galvanizing technology and the formula of the assistant plating, the tensile strength of the galvanized B82MnQL steel wire was decreased by 8%, lower than traditional 10% ~15%. After stabilization, the B82MnQL′s torsion value was about 20 times, with about 6 times of repeated bending. The strength was increased from 1650 MPa to 1710 MPa. The hardness value was higher than that of the galvanized material, raised from 430HV to 450HV, and uniformly dispersed. Conclusion Through optimization of the

  19. Effects of tin and nickel on growth of hot-dip galvanized coating on high-silicon steel surface%锡、镍对高硅钢表面热浸镀锌层生长的影响

    Institute of Scientific and Technical Information of China (English)

    孔纲; 王世卫; 车淳山; 卢锦堂

    2012-01-01

    研究了Zn-Sn和Zn-Sn-Ni浴中高硅钢(含Si 0.36%)表面镀锌层的生长和微观组织变化,探讨了Sn和Ni抑制高硅钢镀层快速生长的原因.结果表明,含Sn锌浴能抑制高硅钢表面镀锌层的快速生长,抑制效果随锌浴中Sn含量的增加而增强.当锌浴中的Sn含量达5%时,高硅钢镀锌层的生长方式发生了改变,由反应扩散控制变为扩散控制.高硅钢在Zn-Sn或Zn-Sn-Ni浴中镀锌时,镀锌层的ζ/η界面形成了Sn或Sn和Ni富集区,在一定程度上阻滞了Fe-Zn扩散.锌浴中添加微量的Ni能显著减少Sn用量,当锌浴中Ni的添加量为0.06%时,Sn的用量可从3%降到1.5%.%The growth and microstructure changes of hot-dip galvanized coating on the surface of high-silicon (0.36% Si) steel were studied in Zn-Sn and Zn-Sn-Ni baths, respectively. The reason why Sn and Ni in zinc bath can inhibit the rapid growth of coating on high-silicon steel was discussed. The results showed that Sn in zinc bath can decrease the rapid growth of zinc coating on surface of high-silicon steel, and the inhibiting effect is reinforced with increasing Sn content in zinc bath. The growth mechanism of coating changes from reaction diffusion control to diffusion control when the Sn content in zinc bath is up to 5%. The Sn-rich or Sn and Ni-rich zone is formed at the interface of ζ/η in the galvanized coating obtained from Zn-Sn or Zn-Sn-Ni bath, suppressing Fe-Zn interdiffusion to some extent. The amount of Sn added can be remarkably reduced by adding a tiny amount of Ni to zinc bath, which is reduced from 3% to 1.5% by 0.06% Ni addition to the zinc bath.

  20. Effect of SRB on hydrogen permeation of hot-dip galvanized steel%硫酸盐还原菌对热镀锌钢材氢渗透行为的影响

    Institute of Scientific and Technical Information of China (English)

    张玉志; 张大磊; 李焰

    2011-01-01

    Hydrogen permeation testing with Devanathan-Stachurski cell and SEM analytical method were used to study the hydrogen permeation behavior of hot-dip galvanized steel in sterilized seawater, sterilized medium and medium inoculated with SRB. The results showed hydrogen permeation behavior of galvanized steel was promoted by some components of the medium. The average hydrogen permeation current density of the sample in sterilized medium was 6 times higher than which in sterilized seawater. The compact film formed by SRB, metabolites of SRB and corrosion products decreased the hydrogen adsorption of the sample although S2- and HS- produced by active SRB could promote the hydrogen peameation behavior, which resulted in the average hydrogen permeation current density of galvanized steel in medium inoculated with SRB 77% lower than which in sterilized medium.SEM results showed few products adhered on the sample immersed in sterilized medium, but a film of corrosion products was formed on the sample immersed in sterilized seawater, and a biofilm of SRB and its metabolites together with the film of corrosion products was formed on the the sample immersed in medium inoculated with SRB,indicating a obvious relation between the biofilm and hydrogen permeation of galvanized steel.%采用Devanatlaan-stachurski 双面电解池检测氢渗透电流技术和扫描电镜分析,研究了热镀锌钢材在灭菌海水、灭菌培养基和接种了硫酸盐还原菌(SRB)的培养基等 3 种介质中的氢渗透行为.氢渗透电流检测结果表明,培养基的部分组分对热镀锌钢材的氢渗透行为有促进作用,试样在灭菌培养基中的氢渗透电流密度的平均值比在灭菌海水中提高了约6倍.尽管活性SRB代谢产生的S和HS能够促进热镀锌钢材的氢渗透行为,但是,由SRB及其代谢产物和它们所黏附的腐蚀产物所形成的致密微生物膜减少了氢的析出和试样对氢的吸收量,导致热镀锌

  1. 钢丝热镀锌-10%铝-混合稀土合金镀层工艺%Process for hot-dip galvanizing zinc-10%aluminum-mixed rare earth alloy on steel wires

    Institute of Scientific and Technical Information of China (English)

    裘海锋; 王英民; 苗立贤; 侯志娇; 苗瀛; 杨冰

    2013-01-01

    A process for hot-dip galvanizing Zn-10%Al-mixed rare earth alloy coating on steel wires based on the principle of electrodeposition (i.e. electroplating a Zn coating prior to galvanizing) was developed as a substitute to common double-dip galvanizing method. The bath composition and operation conditions of individual procedure were presented. It is stressed that the pretreatment of steel wire is the key point. Electrolytic degreasing twice, quartz sand rubbing, and overflow rinsing are employed to produce clean steel wire surface and ensure the quality of coating. The temperature range of molten alloy (455-460 °C) and other technical key points such as the nitrogen wiping temperature were given. The process has advantages of energy saving and low cost as compared with the double-dip method. The causes for the formation of floating aluminum-rich product which influences the coating quality and its treatment method for making the coating smooth and free of defects such as lumps and bumps were discussed. The surface quality of steel wires obtained by the process is stable, and the technical and physicochemical indexes meet the requirements of the standard YB/T 4221-2010 Coated Steel Wire for Machine Woven Steel Wire Mesh.%利用电沉积原理,提出了一种在钢丝表面热浸镀锌-10%铝-稀土合金镀层的工艺,在热浸镀合金之前电沉积一层锌镀层,以代替普通的“双镀法”。给出了各工序的溶液配方及工艺条件。指出重点应放在钢丝的预处理上。采用2道电解脱脂以及石英砂擦拭、水溢流漂洗工艺,得到非常清洁的钢丝表面,才能保证镀层质量。给出了合金液温度范围(455~460°C)、氮气抹拭温度参数等技术要点。该工艺较“双镀法”节约能源,生产成本低。探讨了影响镀层质量的富集铝漂浮物的产生原因及处理办法,使镀层光滑,无“疙瘩”等缺陷。该工艺所得钢丝的表面质量

  2. Factors Affecting MoO4(2-) Inhibitor Release from Zn2Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings.

    Science.gov (United States)

    Shkirskiy, V; Keil, P; Hintze-Bruening, H; Leroux, F; Vialat, P; Lefèvre, G; Ogle, K; Volovitch, P

    2015-11-18

    Zn2Al/-layered double hydroxide (LDH) with intercalated MoO4(2-) was investigated as a potential source of soluble molybdate inhibitor in anticorrosion coatings for hot dip galvanized steel (HDG). The effect of solution pH, soluble chlorides, and carbonates on the release kinetics of the interleaved MoO4(2-) ions from the LDH powder immersed in solutions containing different anions was studied by X-ray diffraction, in situ attenuated total reflectance infrared (ATR-IR) spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The effect of the solution composition on the total release and the release kinetics was demonstrated. Less than 30% of the total amount of the intercalated MoO4(2-) was released after 24 h of the immersion in neutral 0.005-0.5 M NaCl and 0.1 M NaNO3 solutions whereas the complete release of MoO4(2-) was observed after 1 h in 0.1 M NaHCO3 or Na2SO4 and in alkaline solutions. The in situ ATR-IR experiments and quantification of the released soluble species by ICP-AES demonstrated the release by an anion exchange in neutral solutions and by the dissolution of Zn2Al/-LDH in alkaline solutions. The anion exchange kinetics with monovalent anions was described by the reaction order n = 0.35 ± 0.05 suggesting the diffusion control; for divalent anions, n = 0.70 ± 0.06 suggested the control by a surface reaction. Dissolution of Zn from coated HDG with and without Zn2Al/-MoO4(2-) fillers, leaching of MoO4(2-) from the coating, and the electrochemical impedance spectroscopy response of the coated systems were measured during the immersion in 0.5 M NaCl solutions with and without 0.1 M NaHCO3. Without carbonates, the release of soluble MoO4(2-) was delayed for 24 h with no inhibiting effect whereas with 0.1 M NaHCO3 the immediate release was accompanied by the immediate and strong inhibiting effect on Zn dissolution. The concept of controlling the inhibition performance of LDH hybrid coatings by means of the environment

  3. 热镀锌过程挡板对镀层均匀性影响的模拟研究%Computational studies on coating uniformity influenced by baffle in hot dip galvanizing process

    Institute of Scientific and Technical Information of China (English)

    富聿晶; 张红梅; 李培兴; 赵红阳

    2015-01-01

    为解决热镀锌过程中常出现的边部过镀锌缺陷,利用数值模拟方法对热镀锌气刀射流喷吹过程进行仿真研究,分析了挡板厚度对带钢边部压力场的影响;并借助镀层厚度计算模型,计算挡板厚度和边部角度对镀层厚度的作用关系;同时通过不同拉钢速度、气刀狭缝总压等工况,对挡板的厚度及边部角度进行优化。结果表明:随挡板厚度减小,带钢边部作用力增大并逐渐接近中心处;带钢边部镀层厚度随挡板厚度的减小而变薄,随挡板边部角度的增加而先减小后增大;挡板厚度2 mm、边部角度90°时,能有效提高带钢横向作用力和镀层分布的均匀性。%Numerical simulation of the gas⁃jet wiping in hot dip galvanizing process was conducted, aiming to reduce the possible of edge over coating ( EOC) . The effects of baffle thickness and edge angle on pressure fields of strip edge were studied. By using the analytic model of film thickness, the correlation betweent the coating thickness and baffle thickness and edge angle was revealed. Considering different conditions of steel moving speed and total gas knife pressure, the baffle thickness and edge angle were optimized .The results show that the coating thickness of strip edge increases with the decrease of baffle thickness. In addition, with the increase of baffle edge angle, the coating thickness decreases firstly and then increases. When the baffle thickness is 2 mm and the angle is 90°, uniformity distribution of the pressure and coating on the strip is achieved.

  4. 热镀锌板上γ-APT硅烷自组装膜的制备及相容性%Synthesis and Compatibility Evaluation of Self-assembled Monolayers of γ-APT Silane on Hot-Dip Galvanized Steel

    Institute of Scientific and Technical Information of China (English)

    王雷; 刘常升; 石磊

    2011-01-01

    采用交流阻抗谱和接触角的方法研究了γ-APT硅烷的单分子自组装膜在热镀锌钢板表面的成膜过程,以及γ-APT硅烷自组装膜和γ-GPT硅烷的相容性.实验成功制备硅烷单分子自组装膜.组装开始时硅烷分子水解生成硅醇键的一端快速吸附在锌的表面并形成了Si—O—Zn键,硅烷分子之间的硅醇键随即脱水形成Si—O—Si键,从而自组装成为有序、规律排布的单分子自组装膜,组装10 h后膜的完整性最好,随后形成连续性较差的混杂膜.经过10 h组装后的γ-APT硅烷自组装膜与γ-GPT硅烷具有良好的相容性.%The synthesis of γ-APT silane self-assembled monolayers(SAMs) on hot-dip galvanized steel(HDG) and the SAMs compatibility with γ-GPT silane were investigated by electrochemical impedance spectroscopy(EIS) and contact angles analysis.The results showed that the SAMs of the γ-APT silane are deposited on HDG surfaces.First,the SiOH groups of γ-APT are absorbed quickly onto the HDG surfaces to form Si—O—Zn.Then Si—O—Si covalent bonds are formed between the γ-APT silane molecules and the zinc surface,releasing water as a byproduct.The SAMs become stable and the compatibility between the SAMs and γ-GPT silane is good when HDG sheet is immersed in the silane for 10 hours.After that the SAMs is no continuity as a mishmash.

  5. Effect of Nickel Content in Hot - Dip Galvanizing Solution on Morphology as well as Hardness and Wear Resistance of Zinc - Aluminum - Nickel Coating%Zn-Al-Ni热浸镀液中Ni含量对镀层形貌、硬度及耐磨性的影响

    Institute of Scientific and Technical Information of China (English)

    邵大伟; 贺志荣; 张永宏

    2013-01-01

    为了提高热浸镀锌层表面的光洁度、硬度和耐磨性,在Zn-0.01%Al镀液中添加少量Ni,制备了Zn-0.01%Al-(0.02~ 0.12) %Ni镀层.利用金相显微镜、维氏硬度计和摩擦磨损试验机对镀层的表面形貌和性能进行了表征.结果表明,随Ni含量增加,Zn-0.01%Al-xNi镀层的晶粒先减小后增大,硬度先增大后减小;当Ni含量为0.05%时镀层的晶粒最小,硬度最大,摩擦系数最小,耐磨时间较长;Ni含量为0.12%的镀层的耐磨时间虽然最长,但摩擦系数较大.%A small amount of Ni was introduced into hot-dip galvanizing solution (Zn-0. 01%Al bath) to prepare Zn-Al-Ni coating [Al content 0.01% (mass fraction; the same hereafter) ; Ni content 0. 02% ~ 0. 12%] so as to reduce the surface roughness and increase the hardness and wear resistance of hot - dip galvanizing coating. The morphology of as - prepared Zn-Al-Ni coating was observed with a metallurgical microscope, while the hardness and wear resistance of the coating were evaluated with a Vickers hardness meter and a friction and wear tester as well. It was found that, with increasing Ni content in the hot-dip galvanizing solution, the grain size of Zn - Al - Ni coating initially tended to decline but later to rise; and the hardness initially tended to rise but later to decline therewith. The Zn-Al-Ni coating prepared from the hot - dip galvanizing solution containing 0.05% Ni had the smallest grain size, the highest hardness and extended antiwear lifetime. Moreover, though the Zn-Al-Ni obtained from the galvanizing bath containing 0. 12% Ni had the longest antiwear lifetime, it possessed a relatively high friction coefficient.

  6. 热镀锌钢表面铈转化膜的表征与腐蚀电化学行为%Characterization and electrochemical corrosion behavior of cerium conversion coating on hot-dip galvanized steel

    Institute of Scientific and Technical Information of China (English)

    吴海江; 卢锦堂

    2011-01-01

    The cerium conversion coatings were prepared on hot-dip galvanized (HDG) steel sheets treated in 20 g/L Ce(NO3)3·6H2O solution (pH = 4, 25 ℃). The corrosion electrochemical behavior of the cerium conversion coatings was compared with that of blank hot-dip galvanized sample in 5% NaCl solution using polarization curves and electrochemical impedance spectra (EIS). The morphology and composition of the coatings were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion current density of the HDG decreases and the polarization resistance increases after cerium nitrate conversion treatment.While the cerium conversion coatings can markedly restrain the anodic and cathodic reaction during the zinc corrosion process, thereby its corrosion protective efficiency remarkably increases. It is also found that the low-frequency impedance initially increases and then decreases with the treatment time increasing, which demonstrates clearly that the resistance to the migration of electrolyte through the conversion coatings initially increases and subsequently decreases with the treatment time increasing. When the treatment time is prolonged from 30 min to 1 h, the maximal impedance of the conversion coating is up to 8-9 kΩ·cm2 and its corrosion resistance is optimal. The cerium conversion coating is apt to crack in the vicinity of zinc grain boundaries, and the dry riverbed morphology gradually forms with the treatment time increasing. The cerium conversion coating is composed of Ce, Zn and O elements, which mainly consists of CeO2,Ce(OH)4 (or CeO2·2H2O), ZnO and a small quantity of Ce2O3, Ce(OH)3 (or Ce2O3·2H2O).%将热镀锌钢在20 g/L Ce(NO3)·6H2O溶液(pH=4,25℃)中处理10s~24 h,获得铈转化膜试样.应用极化曲线和电化学交流阻抗谱(EIS)研究铈转化膜试样和空白热镀锌试样在5%NaCl溶液中的耐蚀性能.利用扫描电镜(SEM)和X射线光电子能谱(XPS)研

  7. 热镀锌生产线中浴装机器气刀精度调整的研究%RESEARCH ON PRECISION ADJUSTMENT OF THE AIR KNIFE IN THE BATH MOUNTED MACHINE IN THE HOT-DIP GALVANIZING LINE

    Institute of Scientific and Technical Information of China (English)

    任川东

    2014-01-01

    One of the key factors , which decide the galvanized products quality produced by the galvani-zing process , is the air knife precision in the bath mounted machine ( YG Equipment ) in the hot-dip gal-vanizing line .The paper studies the methods of adjusting the air knife precision .Through control optimiza-tion, air knife nozzle openness optimization , air knife parallel control optimization and life position optimiza-tion, the traces of air knife on galvanized sheets are reduced considerably and products quality is enhanced .%热镀锌生产线中浴装机器( YG设备)的气刀装置精度是决定镀锌工序的关键因素,对整个镀锌板材产品质量具有重要意义。本文研究了气刀装置精度调整的方法,通过解体控制优化、气刀喷嘴开口度优化、气刀平行度控制优化以及气刀升降位置优化,使镀锌板上气刀痕迹显著减少,从而提高镀锌板产品的质量。

  8. Microstructure of hot dip coated Fe-Si steels

    Energy Technology Data Exchange (ETDEWEB)

    Danzo, I. Infante, E-mail: ivonneeugenia.infantedanzo@ugent.be; Verbeken, K., E-mail: Kim.Verbeken@UGent.be; Houbaert, Y., E-mail: Yvan.Houbaert@UGent.be

    2011-12-30

    Hot dipping is a coating technique pre-eminently used in industry to galvanize machine parts or steel sheets for constructional applications. However, other hot dipping applications have been developed in order to have a positive effect on specific material properties. For instance, in Fe-Si electrical steels, a Si/Al rich top layer is applied and followed by diffusion annealing to increase the electrical resistivity of the material and consequently, lower the power losses. Hot dipped aluminised mild steels have been developed with increased corrosion resistance for high temperature applications by the development of a dense Al{sub 2}O{sub 3} layer. Regardless of the type of steel coated and the intended application, after the interaction between the molten Al and the solid material, three constituents are formed: Fe{sub 2}Al{sub 5}, FeAl{sub 3} and an Al-rich alloy. The structural morphology, which can negatively affect the wear resistance and the thermal stability, also appears to be highly dependent on the chemical composition of the base material. To study thermo-mechanical and compositional effects on the coating behavior after hot dipping, cold rolling with different reductions was performed on different Fe-Si materials. It was demonstrated that hardness differences between the layers caused crack formation inside the Fe{sub 2}Al{sub 5} layer during subsequent deformation. The present work reports the results obtained on materials that were hot dipped in a hypo-eutectic Al + 1 wt.% Si bath. The bath was used to coat Fe-Si steel substrates with variable silicon content with dipping times ranging from 1 to 20 s. Before dipping, the samples were heated to 700 Degree-Sign C and subsequently immersed in the liquid bath at temperatures of 710 Degree-Sign C, 720 Degree-Sign C and 740 Degree-Sign C. To further evaluate the interactions between Al, Si and Fe, a diffusion annealing treatment at 1000 Degree-Sign C was performed. The main diffusing elements during this

  9. Wear Resistance and Wear Mechanism of a Hot Dip Aluminized Steel in Sliding Wear Test

    Science.gov (United States)

    Xue, Zhiyong; Hao, Xiaoyang; Huang, Yao; Gu, Lingyun; Ren, Yu; Zheng, Ruipeng

    2016-12-01

    Sliding wear experiments were conducted on a hot dip aluminized steel to investigate its wear resistance and wear mechanism. The wear tests were also carried out on a hot dip galvanized steel and the base material (steel Q345) as a comparison. Results show that the wear resistance and hardness of the hot dip aluminized steel are significantly higher than that of the hot dip galvanized steel and the steel Q345 at room temperature. The better wear resistance of the hot dip aluminized steel attributes mainly to the formation of a transition layer containing abundant Fe-Al intermetallic compounds and the transformation of wear-resisting oxides during the friction process. The main phase in the transition layer is Fe2Al5. The thickness of the transition layer is about 90-120 μm. When the wear load increases from 3 N to 19 N, the wear type of the aluminized layer transform from adhesive wear (3 N) into abrasive wear (7 N) and finally into slight wear mixed with oxidation (higher than 11 N).

  10. Effect of soaking temperature on microstructure and properties of 590 MPa grade hot-dip galvanized dual phase steel%均热温度对590 MPa级热镀锌双相钢组织与性能的影响

    Institute of Scientific and Technical Information of China (English)

    邝春福; 郑之旺; 王礞

    2016-01-01

    C-Mn steel were respectively soaked at 760 ℃, 800 ℃ and 850 ℃ for 120 s, and then rapidly cooled to 460 ℃ to simulate the hot-dip galvanizing. The pre-straining (2%) and baking treatment (170 ℃ for 20 min) were carried out to measure the BH values after annealing cycle. The influences of the soaking temperature on microstructure, mechanical properties and bake-hardening behavior of the 590 MPa grade hot-dip galvanized dual phase steel were investigated by means of microscope, SEM, tensile test machine and so on. The results show that the microstructure is composed of ferrite and martensite when annealed at 760-850 ℃, and no bainite is observed. Therefore, the tensile strength of the hot-dip galvanized dual phase steel reaches more than 590 MPa. The steel with excellent comprehensive properties (Rp0.2 =295 MPa, Rm =606 MPa, A=32. 1%, Rm × A=19 450 MPa·%) are obtained by annealing at 800 ℃. The BH value increases first and then decreases with increasing the soaking temperature from 760 ℃ to 850 ℃. And the BH value reaches maximum value (81 MPa) at the soaking temperature of 800 ℃.%将C-Mn钢分别加热至760、800和850℃均热120 s后,快速冷却至460℃以模拟热镀锌工艺。退火后对试验钢进行预应变(2%)和烘烤处理(170℃×20 min)以测量其烘烤硬化( BH)值。通过金相显微镜、扫描电镜、拉伸等技术,研究了均热温度对590 MPa级热镀锌双相钢微观组织、力学性能和烘烤硬化性能的影响。结果表明,在760~850℃范围内退火时,试验钢中未观察到贝氏体组织,微观组织由铁素体和马氏体组成,抗拉强度均达到590 MPa以上。热镀锌双相钢在800℃退火时,具有优良的综合力学性能,其屈服强度为295 MPa,抗拉强度为606 MPa,伸长率为32.1%,强塑积为19450 MPa·%。随着均热温度提高,BH值呈先增加后降低趋势;均热温度为800℃时,BH达最大值81 MPa。

  11. Research on the Corrosion Resistance of Hot Dip Galvanized Coating in Simulated Hot and Humid Acidic Atmospheric Environment%热镀锌层在模拟湿热酸性大气环境中的耐蚀性研究

    Institute of Scientific and Technical Information of China (English)

    刘胜林; 孙亮; 袁毅; 卢才

    2015-01-01

    目的:研究Q420钢表面热镀锌工艺中,Zn和Zn-Al-Ni-RE合金镀层在酸性铜离子加速盐雾试验条件下的耐蚀性能。方法 Q420钢表面预处理后进行热镀锌,根据GB6460—1986进行铜加速醋酸盐雾腐蚀试验,对比纯Zn镀层与Zn-Al-Ni-RE合金镀层的耐蚀性。结果 Ni,RE等元素的加入使镀层表面光亮,组织更加细密。在酸性铜离子加速实验进行到192 h时,纯锌镀层的腐蚀质量损失是合金镀层的2.7倍;72 h后纯锌镀层出现红锈,120 h后合金镀层出现红锈,说明Zn-Al-Ni-RE合金镀层比纯Zn镀层更耐腐蚀。结论通过适量添加Al,Ni与稀土元素,能使Q420钢合金镀层的耐蚀性能大幅度提高。%Objective To study the corrosion resistance of hot dip galvanized pure Zn and Zn-Al-Ni-RE alloy coatings of high-strength steel Q420 under the acidic and copper accelerated salt spray corrosion condition. Methods On the basis of surface pre-treatment, the Q420 steel was treated by hot dip galvanizing. Copper accelerated acetic acid salt spray corrosion test was carried out according to GB 6460—1986, and the corrosion resistance of the pure Zn coating and Zn-Al-Ni-RE coating was compared. Results With the addition of Ni, RE and other elements, the coating surface was bright and the microstructure became finer. After 192 h, the corrosion weight loss of pure zinc coating was 2. 7 times higher than the corrosion weight loss of Zn-Al-Ni-RE alloy coatings un-der the acidic and copper accelerated salt spray corrosion condition. Pure zinc coating showed red rust after 72 h, while Zn-Al-Ni-RE alloy coating showed red rust after 120 h, so Zn-Al-Ni-RE alloy coating was more corrosion resistant than the pure Zn coating. Conclusion By means of adding nickel aluminum elements and rare earth elements, the corrosion resistance of alloy coating was greatly improved.

  12. 连续热镀锌过程带钢边部气流特性的研究%Research on airflow characteristic of the strip edge in hot-dip galvanizing process

    Institute of Scientific and Technical Information of China (English)

    李培兴; 张红梅; 赵红阳; 富聿晶; 孙成钱; 张岩

    2014-01-01

    To explore the strip edge pressure decreases as gas⁃jet wiping in hot⁃dip galvanizing process, a gas impact plate experiment was carried out, and the process of gas jet wiping was also simulated using the measured results. The added edge baffle near the edge of strip which is used to prevent the wall pressure decreases in strip edge was optimized with the help of the analytic model of film thickness. The results show that the airflow of strip edge occurs lateral deflection and the wall pressure in the strip edge is lower than those in center, in addition, the edge air pressure attenuation increases with the rising distance between the air knife and the strip. The edge pressure decreases and the edge over coating problem can be reduced effectively by adding edge baffle, and the best result happens when the thickness of baffle is 2 mm.%为探究连续热镀锌气刀射流拭锌过程中发生的带钢边部压力衰减问题,设计了气流冲击平板实验,对带钢表面气流流向及压力进行测定。基于测量的参数,对该气刀射流喷吹过程进行数值模拟,并结合所推导的镀层厚度计算模型,对为减少带钢边部压力衰减所增设的边部挡板进行了厚度优化。研究结果表明:气刀喷吹时带钢边部气流发生横向偏转,使得带钢边部压力较中心处低,气压衰减率随气刀与带钢的间隔距离增加而增加,增设边部挡板能有效阻碍带钢边部压力衰减和降低边部过镀锌缺陷发生,且挡板厚度为2 mm时的作用效果最佳。

  13. Effect of chemical composition of steel on the structure of hot – dip galvanized coating

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-01-01

    Full Text Available This article describes the effect of the content of conventional steel impurity elements on the thickness and composition of the zinc layer. This article is focused primarily on low-temperature, batch hot-dip galvanizing; however, the continuous coating process is also mentioned. The main discussion covers galvanizing from pure zinc melt, and only touches on galvanizing from melts with the usual amounts of aluminium (0,2 wt. %. Silicon, phosphorus, aluminium and sulfur may have an especially negative effect on the mechanical properties of the coating and its final appearance. The content of ballast carbon and manganese has a rather limited effect on composition and coating thickness.

  14. Corrosion behaviour of hot dip zinc and zinc-aluminium coatings on steel in seawater

    Indian Academy of Sciences (India)

    Yan Li

    2001-08-01

    A comparative investigation of hot dip Zn–25Al alloy, Zn–55Al–Si and Zn coatings on steel was performed with attention to their corrosion performance in seawater. The results of 2-year exposure testing of these at Zhoushan test site are reported here. In tidal and immersion environments, Zn–25Al alloy coating is several times more durable than zinc coating of double thickness. At long exposure times, corrosion rate for the Zn–25Al alloy coating remains indistinguishable from that for the Zn–55Al–Si coating of similar thickness in tidal zone, and is two to three times lower than the latter in immersion zone. The decrease in tensile strength suggested that galvanized and Zn–55Al–Si coated steel suffer intense pitting corrosion in immersion zone. The electrochemical tests showed that all these coatings provide cathodic protection to the substrate metal; the galvanic potentials are equal to – 1,050, – 1,025 and – 880 mV (SCE) for zinc, Zn–25Al alloy and Zn–55Al–Si coating, respectively, which are adequate to keep the steel inside the immunity region. It is believed that the superior performance of the Zn–25Al alloy coating is due to its optimal combination of the uniform corrosion resistance and pitting corrosion resistance. The inferior corrosion performance by comparison of the Zn coating mainly results from its larger dissolution rate, while the failure of the Zn–55Al–Si coating is probably related to its higher susceptibility to pitting corrosion in seawater.

  15. HOT DIPPING ALUMINIZED COATING AS HYDROGEN PERMEATION BARRIER

    Institute of Scientific and Technical Information of China (English)

    Z.Y. Yao; M. Chini; A. Aiello; Benamati

    2001-01-01

    The hydrogen permeation experiment of MANET II with hot dipping aluminized 1oat-ing was performed in temperature range of 573 to 623K, in gas phase and in liquiaPb-17Li phase. The hydrogen permeation reduction factor (PRF) evaluated in gasphase is 620 at 573K and 260 at 623K, and in liquid Pb-17Li phase is 24 45 at 573Kand 12-30 at 623K. The self-healing of coating is obvious and effective above 673K.The pressure dependence of permeation flux indicates strong surface contribution. Theway of filling hydrogen by continuous flow and/or bubble can increase permeation flux.The result of SEM-EDS shows that the microcrack is on the surface of the wetted part,but not on the not wetted part. The crack is superficial and affects only thin outsidelayer not penetrate aluminized layer. The surface elemental analysis shows that Al/Oatomic ratio changes from 2/3 of not wetted part to about 1 of wetted part. Thedamage of coating surface seems to be related to the interaction of outside layer withliquid Pb-17Li and thermal stress during heating sample.

  16. Effect of Cr, Mo and W on the Microstructure of Al Hot Dipped Carbon Steels

    Energy Technology Data Exchange (ETDEWEB)

    Trung, Trinh Van [School of Materials Science and Engineering, Hanoi University of Science and Technology, Hanoi (Viet Nam); Kim, Min Jung; Park, Soon Yong; Vadav, Poonam; Abro, Muhammad Ali; Lee, Dong Bok [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-02-15

    A low carbon steel, Fe-2.25%Cr steel (ASTM T22), and Fe-2.25%Cr-1.6%W steel (ASTM T23) were aluminized by hot dipping into molten Al baths. After hot-dipping, a thin Al-rich topcoat and a thick alloy layer formed on the surface. The topcoat consisted primarily of a thin Al layer that contained a small amount of Fe, whereas the alloy layer consisted of Al-Fe intermetallics such as Al{sub 5}Fe{sub 2} and AlFe. Cr, Mo, and W in T22 and T23 steels reduced the thickness of the topcoat and the alloy layer, and flattened the reaction front of the aluminized layer, when compared to the low carbon steel.

  17. Effects of Copper and Titanium Elements on the Coating's Properties of Hot-Dipping-Aluminum Steel

    Institute of Scientific and Technical Information of China (English)

    JIA Wei-ping; MA Yun-long; HU Lin; KE Wei

    2004-01-01

    The steel plates for testing obtained a clean and fresh surface after degreasing by alkali and acidity and to be protested from reoxidation by being dipped into liquid wax. The results after hot dipping experiments in lab. showed that a complete aluminized coat with a good property could be obtained under a condition of hot-dipping temperature at about 730 ℃, hot -dipping time at about 2 minutes. It was found that the transition layer was mainly composed of Fe2 Al5 intermetallic compound by SEM (Scanning Electronic Microscope) observation. Effects of elements copper and titanium in aluminum coating on adherence quality, corrosion resistance performance and thickness of the transition layer were investigated, the following results were drawn: The adherence quality is strongly enhancedby copper element and gives the best performance at the 2% mass percent content of copper, while it is almost indifferent with titanium content. The corrosion resistance property is enhanced by titanium and is deteriorated by copper, when the mass percent content of titaniumis 0.3% , the coating exhibits the best anti-corrosion performance. At present condition, both copper and titanium make transition layer thinner.

  18. The Effect of La on the Microstructure and Corrosion-resistance of Hot-dipped Aluminizing Steel

    Institute of Scientific and Technical Information of China (English)

    WENJiu-ba; ZHANGWei; LIXiao-yuan; LIQuan-an

    2004-01-01

    The effect of the content of rare-earth La on the microstructure and corrosion-resistance of hot-dipped aluminum was investigated in this paper. The results show that, under the same technology conditions, the thickness of hot-dipped aluminizing layer by adding the appropriate content of rare-earth La is about 2-3 times as much as that without rare-earth La, and the microstructure of hot-dipped aluminizing layer has also greatly changed ,and a great deal of phase Fe3A1 waspreci pitated along the boundary of a phase. The corrosion resistance of the hot-dipped layer with rare-earth is greatly increased.

  19. The Effect of La on the Microstructure and Corrosion-resistance of Hot-dipped Aluminizing Steel

    Institute of Scientific and Technical Information of China (English)

    WEN Jiu-ba; ZHANG Wei; LI Xiao-yuan; LI Quan-an

    2004-01-01

    The effect of the content of rare-earth La on the microstructure and corrosion-resistance of hot-dipped aluminum was investigated in this paper. The results show that, under the same technology conditions, the thickness of hot-dipped aluminizing layer by adding the appropriate content of rare-earth La is about 2~3 times as much as that without rare-earth La, and the microstructure of hot-dipped aluminizing layer has also greatly changed ,and a great deal of phase Fe3Al was precipitated along the boundary of α phase. The corrosion resistance of the hot-dipped layer with rare-earth is greatly increased.

  20. UTILIZATION OF INDUCTION HEATING TECHNOLOGY IN GALVANIZING LINES

    Directory of Open Access Journals (Sweden)

    Victor Demidovich

    2015-09-01

    Full Text Available Continuous Hot-Dip Galvanizing lines are widely used for the production of coated steel sheets. Quality improvement measures are of great importance for this type of line. A significant proportion of production and quality losses when operating these types of lines occurs when production is transitioning from one strip gauge/thermal cycle to another. Utilizing induction heating technology, in combination with a sophisticated control system, can dramically decrease yield losses during transitions. Dynamic Transition and Production Planning Models have recently been developed for the simulation and control of the continuous hot-dip galvanizing line. The results of this work have been implemented in some galvanizing lines with production rate up to 350,000-ton annual capacity.

  1. Preparation of tetrapod-like ZnO whiskers from waste hot dipping zinc

    Institute of Scientific and Technical Information of China (English)

    陈艺锋; 唐谟堂; 杨声海; 张保平; 杨建广

    2004-01-01

    Large and uniform tetrapod-like ZnO whiskers (T-ZnO) were prepared from waste hot dipping zinc by vapor oxidation and examined by means of X-ray diffraction and ICP-AES analysis and scanning electron microscope.The products are pure hexagonal wurtzite crystals with tetrapod shape and edge size of center body 5 - 6μm and needle length of 100 - 130 μm. The size and shape of ZnO particles are fully controlled by the growth conditions and TZnO can be obtained only at 850 - 1 000 ℃ and total gas flow rate ranging from 40 to 250 L @ h-1 in which the size of the T-ZnO particles varies slightly with temperature. The process of the formation of T-ZnO is that T-ZnO may nucleate at the initial stage with a complete tetrapod shape and develop to the large size, but not the process of preferential growth of octahedral nuclei and subsequent growth of the needles. The experiment presents a new method to prepare T-ZnO economically by using the waste hot dipping zinc.

  2. Part I. Thermodynamic and Kinetic Aspects of the Hot Dip (Zn - Coating Formation

    Directory of Open Access Journals (Sweden)

    Wołczyński W.

    2014-10-01

    Full Text Available A hot dip (Zn – coating formation is carried out in the industry conditions. Two types of the steel substrate are applied to the experiment. Two morphologically different coatings are obtained, accordingly. A hot dip (Zn – coating formation is also carried out in the laboratory conditions for making some additional explanations of the revealed phenomena. The thickening of the - phase sub-layer is observed in details to determine time of the transition from stable into meta-stable solidification. The Fe-Zn phase diagrams for stable and meta-stable equilibrium are calculated, respectively. The phase diagram for dissolution is also determined. The criterion of the higher temperature of the solid/liquid (s/l interface is successfully applied to the Fe-Zn system to justify the competition between stable and meta-stable solidification. The mass balance verification is performed for the (Zn - coating in order to define the nominal Zn–solute concentration required by dissolution and next by solidification. The Zn – solute concentration in the dissolution, super-saturation and saturation zones are determined thermodynamically. The growth kinetics is described for all the sub-layers in the (Zn – coating.

  3. Fine structures in Fe3Al alloy layer of a new hot dip aluminized steel

    Indian Academy of Sciences (India)

    Li Yajiang; Wang Juan; Zhang Yonglan; X Holly

    2002-12-01

    The fine structure in the Fe–Al alloy layer of a new hot dip aluminized steel (HDA) was examined by means of X-ray diffractometry (XRD), electron diffraction technique, etc. The test results indicated that the Fe–Al alloy layer of the new aluminized steel mainly composed of Fe3Al, FeAl and -Fe (Al) solid solution. There was no brittle phase containing higher aluminum content, such as FeAl3 (59.18% Al) and Fe2Al7 (62.93% Al). The tiny cracks and embrittlement, formerly caused by these brittle phases in the conventional aluminum-coated steel, were effectively eliminated. There was no microscopic defect (such as tiny cracks, pores or loose layer) in the coating. This is favourable to resist high temperature oxidation and corrosion of the aluminized steel.

  4. Effects of lanthanum addition on corrosion resistance of hot-dipped galvalume coating

    Institute of Scientific and Technical Information of China (English)

    YANG Dong; CHEN Jianshe; HAN Qing; LIU Kuiren

    2009-01-01

    Effects of La addition on corrosion resistance of hot-dipped galvalume coating steel wire were investigated. The corrosion resistance of Zn-Al-Si-La alloy coatings containing 0, 0.02wt.%, 0.05wt.%, 0.1wt.% and 0.2wt.% La were evaluated by various tests such as copper-accelerated acetic acid salt spray testing (CASS), immersion test in 3.5% NaCl solution, electrochemical tests including weak polarization curves and electrochemical impedance spectroscopy (EIS) tests, scanning electron microscope (SEM) test and X-ray diffraction (XRD) test. It was found that the corrosion resistance of galvalume coating could be improved by adding proper amounts of La. Meanwhile, the mechanism of the improvement of corrosion resistance by La addition was discussed.

  5. Hot-Dip Aluminizing of Low Carbon Steel Using Al-7Si-2Cu Alloy Baths

    OpenAIRE

    Prashanth Huilgol; Suma Bhat; K. Udaya Bhat

    2013-01-01

    Hot-dip aluminizing of low carbon steel was done in molten Al-7Si-2Cu bath at 690°C for dipping time ranging from 300 to 2400 seconds. Characterization of the intermetallics layer was done by using scanning electron microscope with energy dispersive spectroscopy. Four intermetallic phases, τ5-Al7Fe2Si, θ-FeAl3, η-Fe2Al5, and τ1-Al2Fe3Si3, were identified in the reaction layer. τ5- Al7Fe2Si phase was observed adjacent to aluminum-silicon topcoat, θ-FeAl3 between τ5 and η-Fe2Al5, η-Fe2Al5 adjac...

  6. The morphology of coating/substrate interface in hot-dip-aluminized steels

    Energy Technology Data Exchange (ETDEWEB)

    Awan, Gul Hameed [Metallurgical and Materials Engineering Department, University of Engineering and Technology, Lahore 54890 (Pakistan); Hasan, Faiz ul [Metallurgical and Materials Engineering Department, University of Engineering and Technology, Lahore 54890 (Pakistan)], E-mail: drfaiz@uet.edu.pk

    2008-01-15

    In hot-dip-aluminized (HAD) steels, the morphology and the profile of the interface between the aluminum coating and the substrate steel, are affected both by the composition of the molten aluminum as well as by the composition, and even the microstructure, of the substrate steel. This effect has been investigated using optical and scanning electron microscopy, and X-ray diffraction. The reaction between the steel and the molten aluminum leads to the formation of Fe-Al inter-metallic compounds on the steel surface. The thickness of the inter-metallic compound layer as well as the morphology of the interface between the steel and the interlayer varies with the silicon content of the molten aluminum. In hot-dip-aluminizing with pure aluminum, the interlayer is 'thick' and exhibits a finger-like growth into the steel. With a gradually increasing addition of silicon into the aluminum melt, the thickness of the interlayer decreases while the interface between the interlayer and the substrate gradually becomes 'smoother'. With an increase in the carbon content of the substrate steel the growth of the interlayer into the steel is impeded by the pearlite phase, whereas the ferrite phase appears to dissolve more readily. X-ray diffraction and electron microscopic studies showed that the interlayer formed in samples aluminized in pure aluminum, essentially consisted of orthorhombic Fe{sub 2}Al{sub 5}. It was further observed that the finger-like grains of Fe{sub 2}Al{sub 5} phase exhibited a preferred lattice orientation. With a gradual addition of silicon into the aluminum melt, a cubic phase based on Fe{sub 3}Al also started to form in the interlayer and replaced most of the Fe{sub 2}Al{sub 5}.

  7. Research of 1770 MPa galvanized steel wire for stay cable of domestic bridges

    Institute of Scientific and Technical Information of China (English)

    Ding Feng; Sang Chunming; Zhou Daiyi; Bai Bingdong

    2009-01-01

    This paper focuses on introducing the manufacture technology of 1 770 MPa galvanized steel wires for stay cables applied to domestic bridges. During the development practices of high strength galvanized wire for stay cables used in Sutong Bridge, Baosteel has established three key technologies based on research of manufacture technology and technical innovation. The three key technologies are: "Double Tensioning + limiter die" process, "dominant process + fine adjustment" in integrated optimization technology and "three-level control" in hot dip galvanization. With these key technologies, Baosteet has produced 1 770 MPa galvanized wires for stay cable, which has high tensile strength, low relaxation and good torsion performances.

  8. UTILIZATION OF INDUCTION HEATING TECHNOLOGY IN GALVANIZING LINES

    OpenAIRE

    2015-01-01

    Continuous Hot-Dip Galvanizing lines are widely used for the production of coated steel sheets. Quality improvement measures are of great importance for this type of line. A significant proportion of production and quality losses when operating these types of lines occurs when production is transitioning from one strip gauge/thermal cycle to another. Utilizing induction heating technology, in combination with a sophisticated control system, can dramically decrease yield losses during transiti...

  9. Investigation on hot-dip aluminised and subsequent HIP'ped steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Glasbrenner, H.; Konys, J. E-mail: juergen.konys@imf.fzk.de

    2001-11-01

    Tritium permeation can be reduced significantly by a suitable coating on the structural material. Since alumina has the capability of tritium permeation reduction the development of such coatings on ferritic martensitic steels by hot-dip aluminising of F82H-mod. steel sheets was already performed successfully. An improvement of these coatings were achieved by subsequent HIP'ping at 1040 deg. C for 0.5 h at 250, 500 and 750 bar and subsequently tempered at 750 deg. C for 1 h at 1 bar. All samples were investigated by means of metallographical examination, EDX line scan analysis and Vickers micro hardness measurements. The high pressure produced two observed changes: firstly, with increasing pressure the thickness of the FeAl phase increases and the thickness of the {alpha}-Fe(Al) phase decreases, and secondly the formation of pores could be suppressed successfully. The Vickers micro hardness of the base material F82H-mod. is not influenced by the heat-treatment under pressure and is about 215 HV.

  10. Study on the cluster of floating dross before nucleating during hot-dipping process

    Institute of Scientific and Technical Information of China (English)

    WEI; Yunhe; ZHANG; Changqiao; QIN; Jingyu; LIU; Chengbu

    2005-01-01

    During hot-dipping in molten Zn-55Al, the forming of "floating" dross is closely related with the interaction between the Al and the Fe atoms. Utilizing the thita-thita X-ray diffraction and the Percus-Yevick hard sphere model, this paper investigates the structure of molten Al3Fe that is an approximant of partial melt in practical Zn-55Al alloy melt. It is found that in the melt there exist clusters that resemble the structure of intermetallic compound Al3Fe. The strong interaction between Al and Fe atoms is also indicated by the deficiency of the coordination number from 12 and the shrinkage of averaged atomic diameter. Based on such information, it is speculated that in the molten Zn-55Al, with the accumulation of Fe, Al3Fe-like clusters form with priority, then grow into dross. On the other hand, after deflating of the effective hard sphere diameter of pure Al atom and enlarging that of the pure Fe atom, the modified model can achieve reasonable fit to the experimental structure factor. Hard sphere modeling also gave a good estimation of the mass density 3.65 g/cm3 of liquid Al3Fe alloy at 1550℃. Compared with the density of 3.7 g/cm3 of Zn-55Al, the reason for dross floating is satisfactorily understood.

  11. Hot-Dip Aluminizing of Low Carbon Steel Using Al-7Si-2Cu Alloy Baths

    Directory of Open Access Journals (Sweden)

    Prashanth Huilgol

    2013-01-01

    Full Text Available Hot-dip aluminizing of low carbon steel was done in molten Al-7Si-2Cu bath at 690°C for dipping time ranging from 300 to 2400 seconds. Characterization of the intermetallics layer was done by using scanning electron microscope with energy dispersive spectroscopy. Four intermetallic phases, τ5-Al7Fe2Si, θ-FeAl3, η-Fe2Al5, and τ1-Al2Fe3Si3, were identified in the reaction layer. τ5- Al7Fe2Si phase was observed adjacent to aluminum-silicon topcoat, θ-FeAl3 between τ5 and η-Fe2Al5, η-Fe2Al5 adjacent to base material, and τ1-Al2Fe3Si3 precipitates within Fe2Al5 layer. The average thickness of Fe2Al5 layer increased linearly with square root of dipping time, while for the rest of the layers such relationship was not observed. The tongue-like morphology of Fe2Al5 layer was more pronounced at higher dipping time. Overall intermetallic layer thickness was following parabolic relationship with dipping time.

  12. High temperature corrosion of hot-dip aluminized steel in Ar/1%SO2 gas

    Science.gov (United States)

    Abro, Muhammad Ali; Lee, Dong Bok

    2017-01-01

    Carbon steels were hot-dip aluminized in Al or Al-1at%Si baths, and corroded in Ar/1%SO2 gas at 700-800 °C for up to 50 h. The aluminized layers consisted of not only an outer Al(Fe) topcoat that had interdispersed needle-like Al3Fe particles but also an inner Al-Fe alloy layer that consisted of an outer Al3Fe layer and an inner Al5Fe2 layer. The Si addition in the bath made the Al(Fe) topcoat thin and nonuniform, smoothened the tongue-like interface between the Al-Fe alloy layer and the substrate, and increased the microhardness of the aluminized layer. The aluminized steels exhibited good corrosion resistance by forming thin α-Al2O3 scales, along with a minor amount of iron oxides on the surface. The interdiffusion that occurred during heating made the aluminized layer thick and diffuse, resulting in the formation of Al5Fe2, AlFe and AlFe3 layers. It also smoothened the tongue-like interface, and decreased the microhardness of the aluminized layer. The non-aluminized steel formed thick, nonadherent, nonprotective (Fe3O4, FeS)-mixed scales.

  13. Performance and Application of Hot Dip Aluminized Steel%热浸镀铝钢的性能及用途

    Institute of Scientific and Technical Information of China (English)

    李华飞; 俞敦义; 等

    2001-01-01

    为了便于研究人员和用户了解、掌握热浸镀铝钢的性能及其用途,进一步推动我国在这方面的大力发展,作者综述了热浸镀铝钢镀层的机械性能、耐腐蚀性能、抗高温氧化性能和其他性能及其在各工程领域上的应用情况,列出了部分性能指标。%The mechanical performance,corrosion resistance and high temperature oxidation resistance of hot dip aluminized steel were summarized.The hot- dip aluminized steel could extensively be used in various engineering fields.

  14. Benchmarking of energy consumption of continuous galvanizing lines

    Science.gov (United States)

    Gopalakrishnan, B.; Chavan, R.

    2005-11-01

    A case study revealed that more than 13,500 MMBtu of energy is wasted annually when a single galvanizing line is off-production for hardware replacement for duration of a few hours every 2 weeks. This energy if utilized for production will yield about 13,000 tons of Galvanized Sheet Steel annually from a single galvanizing line. Thus for the 57 [1] hot dip galvanizing lines in US this figure results in a production loss of 741,000 tons/year. An attempt has been made to develop a spreadsheet that will take into account all the major energy consuming equipment in a typical hot dip continuous line. It maintains a track of the current production and energy consumption. It can simulate a scenario where either the number of shutdowns or the hours per shutdown will be reduced as a consequence of better material developed by the researchers. Different charts pertaining to energy consumed by different equipment group, total cost of energy spent on natural gas and electricity, MMBtu/Ton, Tons/Year and Production time before shutdowns assists the engineers decide the best operating stretch to suite their production rate and optimize energy consumption to some extent. Validation data gathered from the three well established galvanizing lines powers this spreadsheet to forecast annual increase in production and thus helps judge the performance of the new hardware.

  15. Outbursts formation on low carbon and trip steel grades during hot-dip galvanisation

    Science.gov (United States)

    Petit, E. J.; Lamm, L.; Gilles, M.

    2004-12-01

    Low carbon and TRIP grade steels have been hot dip galvanised in order to study outbursts formation. Microstructure and texture of intermetallic phases have been observed after selective electrochemical etching by scanning electron microscopy. Potential versus time (chronopotentiometric) characteristics were recorded in order to monitor surface modifications. This combination of techniques enable to quantify and observe intermetallic phase one by one. The overall thickness of coating on both substrates are similar. However, microstructures of Fe-Zn intermetallic phases are very different on both grades. In particular, the V phase is dense on standard steel but develops a highly branched filament structure on TRIP steel. The transformation of V phase to d and G1 are limited on TRIP steel. Differences of texture provide clues for understanding mechanisms of formation of outbursts. They can account for the differences of mechanical properties and corrosion resistance. Silicon from the substrate influences the reactivity of TRIP steels due to capping and local reactions. La formation des outbursts a été étudiée sur un acier bas carbone et sur un acier TRIP galvanisés. Les épaisseurs des revêtements sont similaires. Néanmoins, les observations microscopiques et les érosions électrochimiques montrent que la répartition des phases intermétalliques et leurs microstructures diffèrent sensiblement en fonction de la nature du substrat. Ces différences expliquent les propriétés mécaniques et anticorrosions. L’encapsulation de la surface par les oxydes de silicium freine la transformation de la phase dzêta en delta et gamma sur l’acier TRIP.

  16. Microstructural Changes of Al Hot-Dipped P91 Steel during High-Temperature Oxidation

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Abro

    2017-02-01

    Full Text Available The 9Cr-1Mo steel (ASTM P91 was hot-dip aluminized, and its microstructural changes during oxidation were studied. Before oxidation, the coating consisted of (Al-rich topcoat containing a small amount of Al5Fe2 and Al13Fe4/(Al13Fe4-rich, Al13Fe4-containing alloy layer/(Al5Fe2 alloy layer containing a small amount of Al9Cr4 precipitates, from the surface. During oxidation at 700–900 °C for 20–100 h, Al diffused inward and the substrate elements migrated outward to broaden and soften the coating, and also to transform (high Al-Fe intermetallics to (low Al-Fe intermetallics. The phases in the coating progressively transformed during oxidation as follows; (Al-rich topcoat/(Al5Fe2–rich, Al13Fe4-containing alloy layer/(Al5Fe2 alloy layer→(α-Al2O3 scale/(Al13Fe4–rich, Al5Fe2-containing layer/(Al5Fe2 layer/(AlFe interlayer→(α-Al2O3 scale/(AlFe–rich, Al5Fe2-containing layer/(AlFe layer/(AlFe3 layer→((α-Al2O3, Fe2O3-mixed scale/(AlFe3 layer/(Fe(Al layer from the surface. As the oxidation progressed, the scale changed from α-Al2O3 to the (α-Al2O3, Fe2O3-mixture, which provided the necessary oxidation resistance.

  17. Orientation Dependence of Cracking in Hot-Dip Zn-Al-Mg Alloy Coatings on a Sheet Steel

    Science.gov (United States)

    Park, Y. B.; Kim, I. G.; Kim, S. G.; Kim, W. T.; Kim, T. C.; Oh, M. S.; Kim, J. S.

    2017-03-01

    The present study was aimed at investigating a basic cause of cracking in hot-dip Zn-Al-Mg alloy coatings on an extra deep drawing quality sheet steel. The electron backscattering diffraction technique was employed to examine the crystallographic planes of the cracks generated before and after bending deformation of the coated steel sheets. It was clarified that the occurrence of cracking in the Zn-Al-Mg alloy coatings absolutely depends on the orientation of the primary Zn and eutectic Zn alloy phases. Finally, a cracking mechanism was proposed on the basis of the anisotropy of thermal expansion and the Young's modulus in the phases constituting the coatings.

  18. Life Improvement of Pot Hardware in Continuous Hot Dipping Processes Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Xingbo Liu

    2006-01-18

    The process of continuous galvanizing of rolled sheet steel includes immersion into a bath of molten zinc/aluminum alloy. The steel strip is dipped in the molten bath through a series of driving motors and rollers which control the speed and tension of the strip, with the ability to modify both the amount of coating applied to the steel as well as the thickness and width of the sheet being galvanized. There are three rolls used to guide the steel strip through the molten metal bath. The rolls that operate in the molten Zn/Al are subject to a severely corrosive environment and require frequent changing. The performance of this equipment, the metallic hardware submerged in the molten Zn/Al bath, is the focus of this research. The primary objective of this research is to extend the performance life of the metallic hardware components of molten Zn/Al pot hardware by an order of magnitude. Typical galvanizing operations experience downtimes on the order of every two weeks to change the metallic hardware submerged in the molten metal bath. This is an expensive process for industry which takes upwards of 3 days for a complete turn around to resume normal operation. Each roll bridle consists of a sink, stabilizer, and corrector roll with accompanying bearing components. The cost of the bridle rig with all components is as much as $25,000 dollars just for materials. These inefficiencies are of concern to the steel coating companies and serve as a potential market for many materials suppliers. This research effort served as a bridge between the market potential and industry need to provide an objective analytical and mechanistic approach to the problem of wear and corrosion of molten metal bath hardware in a continuous sheet galvanizing line. The approach of the investigators was to provide a means of testing and analysis that was both expeditious and cost effective. The consortium of researchers from West Virginia University and Oak Ridge National Laboratory developed

  19. Surface topography evolvement of galvanized steels in sheet metal forming

    Institute of Scientific and Technical Information of China (English)

    HOU Ying-ke; YU Zhong-qi; ZHANG Wei-gang; JIANG Hao-min; LIN Zhong-qin

    2009-01-01

    U-channel forming tests were performed to investigate the surface topography evolvement of hot-dip galvanized(GI) and galvannealed(GA) steels and the effects of die hardness on sheet metal forming(SMF). Experimental results indicate that the surface roughness values of the two galvanized steels increase with the number of forming, i.e., the surface topographies of galvanized steels are roughened in SMF. Moreover, GI steel has a better ability of damage-resistance than GA steel. The mechanisms of topography evolvement are different in the forming of GI and GA steels. Scratch is the main form of surface damage in the forming of GI steels. The severity of scratch can be decreased by increasing die hardness. GA steel results in exfoliating of the coating firstly and then severe scratching. The surface topography of galvannealed steels can be improved by increasing die hardness. However, the hardness should not be too high.

  20. Effect of Al Hot-Dipping on High-Temperature Corrosion of Carbon Steel in N2/0.1% H2S Gas

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Abro

    2016-02-01

    Full Text Available High-temperature corrosion of carbon steel in N2/0.1% H2S mixed gas at 600–800 °C for 50–100 h was studied after hot-dipping in the aluminum molten bath. Hot-dipping resulted in the formation of the Al topcoat and the Al-Fe alloy layer firmly adhered on the substrate. The Al-Fe alloy layer consisted primarily of a wide, tongue-like Al5Fe2 layer and narrow Al3Fe layer. When corroded at 800 °C for 100 h, the Al topcoat partially oxidized to the protective but non-adherent α-Al2O3 layer, and the interdiffusion converted the Al-Fe alloy layer to an (Al13Fe4, AlFe3-mixed layer. The interdiffusion also lowered the microhardness of the hot-dipped steel. The α-Al2O3 layer formed on the hot-dipped steel protected the carbon steel against corrosion. Without the Al hot-dipping, the carbon steel failed by forming a thick, fragile, and non-protective FeS scale.

  1. THE METHOD OF ROLL SURFACE QUALITY MEASUREMENT FOR CONTINUOUS HOT DIP ZINC COATED STEEL SHEET PRODUCTION LINE

    Directory of Open Access Journals (Sweden)

    Ki Yong Choi

    2015-01-01

    Full Text Available The present paper describes a developed analyzing system of roll surface during the process of continuous hot dip zinc coated steel sheet production line, in particular, adhering problem by transferred inclusions from roll to steel sheet surface during annealing process so called the pickup. The simulated test machine for coated roll surface in processing line has been designed and performed. The system makes it possible to analyze roll surface condition according to pickup phenomena from various roll coatings concerning operating conditions of hearth rolls in annealing furnace. The algorithm of fast pickup detection on surface is developed on the base of processing of several optical images of surface. The parameters for quality estimation of surface with pickups were developed. The optical system for images registration and image processing electronics may be used in real time and embed in processing line.

  2. Thickness measurement of Sn-Ag hot dip coatings on Large Hadron Collider Superconducting strands by coulometry

    CERN Document Server

    Arnau-Izquierdo, G; Oberli, L R; Scheuerlein, C; Taborelli, M; 10.1149/1.1715094

    2004-01-01

    Amperostatic coulometry is applied for the thickness measurement of Sn-Ag hot dip coatings, which comprise an extended Sn-Cu interdiffusion layer. Complementary measurements, notably weight loss, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence (XRF) and dynamic secondary ion mass spectroscopy (DSIMS) have been performed in order to obtain a better interpretation of the coulometry results. Based on the experimental results presented in this article the three potential changes that are observed during coulometry measurements are ascribed to (1) the entire dissolution of pure Sn, (2) the formation of a CuCl salt layer and (3) the surface passivation. The measurement of the pure Sn mass is well reproducible despite of strong coating thickness variations that are detected by XRF. Several experimental problems, in particular a coating undercutting, hamper the determination of the Sn mass in the intermetallic Sn-Cu layer.

  3. Thickness measurement of Sn-Ag hot dip coatings on Large Hadron Collider Superconducting strands by coulometry

    CERN Document Server

    Scheuerlein, C; Arnau-Izquierdo, G; Oberli, L R; Taborelli, M; 10.1149/1.1715094

    2004-01-01

    Amperostatic coulometry was applied for the thickness measurement of Sn-Ag hot dip coatings, which comprise an extended Sn-Cu interdiffusion layer. Complementary measurements, notably weight loss, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, X-ray fluorescence (XRF), and dynamic secondary ion mass spectroscopy were performed in order to obtain a better interpretation of the coulometry results. Based on the experimental results presented in this article, the three potential changes observed during coulometry measurements are ascribed to (i) the entire dissolution of pure Sn, (ii) the formation of a CuCl salt layer, and (iii) the surface passivation. The measurement of the pure Sn mass is well reproducible despite strong coating thickness variations detected by XRF. Several experimental problems, in particular, a coating undercutting, hamper the determination of the Sn mass in the intermetallic Sn-Cu layer. (19 refs).

  4. Berberine as an Environmental-Friendly Inhibitor for Hot-Dip Coated Steels in Diluted Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    Hong Ju; Yulin Ju; Yan Li

    2012-01-01

    The inhibition effect of an excellent environmental-friendly corrosion inhibitor--berberine on hot-dip coated steels in the diluted HCI has been investigated by using quantum chemistry analysis, mass-loss tests, elec- trochemical measurements and scanning electron microscopy (SEM) observation. Calculation results show that berberine has a nearly planar structure with a number of active centers. The value of Mulliken charge, and the distribution of the highest occupied molecular orbital (HOMO) and the lower unoccupied molecular orbital (LUMO) imply that berberine has a good ability of electron exchange with metal surface. The test results indicate that inhibition efficiency (IE%) increases with the inhibitor concentration and the highest IE can reach 99%. Adsorption of berberine on the coating surface follows Langmuir adsorption isotherm with a single molecular layer by chemisorption.

  5. Effect of Mg content on microstructure and corrosion behavior of hot dipped Zn–Al–Mg coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Caizhen; Lv, Haibing [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Zhu, Tianping [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand); Zheng, Wanguo [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Yuan, Xiaodong, E-mail: xdyuan@caep.cn [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Gao, Wei, E-mail: w.gao@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand)

    2016-06-15

    In this article, Zn–Al–Mg coatings were prepared by hot dipping method. The surface morphology, cross–section microstructure, microhardness, composition, corrosion behaviour of ZAM coatings were investigated by using X–ray diffraction (XRD), Optical microscope, Environmental scanning electron microscopy equipped with EDS (FESEM–EDS), Microhardness tester and Electrochemical analysis respectively. Corrosion test was also performed in a standard salt fog spray chamber. Microstructure studies indicates that Zn grain size was refined and eutectic areas at Zn grain boundary areas increased with increasing Mg content. ZA5M1.5 and ZA5M2 coatings have two distinct layers. Mg tends to exist in the outer layer while Al is in the inner layer. The inner layer is composed of Al{sub 5}Fe{sub 2}Zn{sub 0.4} intermetallic, which may to contribute to the microhardness. The outer layer is Zn grains surrounded by Zn–Mg etutectics, which may improve the corrosion resistance. The microhardness is more than 700 HV{sub 50g} for Al-rich layer and around 151 HV{sub 25g} for Mg-rich layer. The improved corrosion resistance of Zn–5%Al-1.5%Mg coating comes from the corrosion product of flocculent type simonkolleite, which prolongs the micro-path and impedes the movement of O{sub 2} and H{sub 2}O, ultimately retards the overall corrosion process. - Highlights: • Two-layer structured Zn–Al–Mg coatings were prepared by hot dipping method. • Mg exists in the outer layer while Al exists in the inner layer of Zn–Al–Mg coating. • Zn–Al–Mg coating has better protective ability than Zn and Zn–Al coatings. • The Mg-modified simonkolleite is the reason of the enhanced corrosion resistance.

  6. Studies into the Factors that Affects the Service Integrity of Galvanizing Kettle

    Directory of Open Access Journals (Sweden)

    Muhammed Olawale Hakeem AMUDA

    2008-12-01

    Full Text Available The finding of studies into the factors that affects optimal performance of galvanizing kettle is presented in this paper. The production schedule and history of a failed galvanizing kettle for 3-consecutively years in a hot-dip galvanizing industry was collated and analyzed. The analysis of the collated data revealed that average galvanizing temperatures for the 3-year under review were 483.9°C (2003, 482.25°C (2004 and 482°C (2005 respectively. The amount of flux, and dross produced in the corresponding years were 169.15kg and 31.6 tons, 56.31kg and 10.5 tons and 101.14 and 18.91 tonnes for 2003, 2004 and 2005 respectively. During these years, zinc consumed averaged 647, 334 and 446 tonnes respectively.Stochiometry evaluation of flux, and dross in a hot-dip galvanizing process determined flux required as 60 kg/year and dross produced as 90 slabs / month.The study revealed that the lifespan of galvanizing kettle is greatly reduced by temperature fluctuation, dross formation, excess flux additions and combinations of these factors.It is recommended that improved service integrity of galvanizing kettle is assured at galvanizing temperature of 460°C, flux consumption of 0.15 –0.20kg daily and constant removal of dross at 3-5 slabs per day. This reduces the formation of skim lines, which leads to pits on the walls of the kettle.

  7. Electrochemical Behavior and Microstructure of Recyclable Aluminium-magmesium Alloy Hot-dip Coating Deposited on Low Carbon Steel Substrates

    Institute of Scientific and Technical Information of China (English)

    Panomkorn KWAKHONG; Apichart ARTNASEAW; Chaiyaput KRUEHONG

    2015-01-01

    With the abundance and good corrosion resistance of aluminium, hot-dip technique was used to prepare the recycled Al with 8.2 mass% Mg alloy coating on low carbon steel substrates. Electrochemical behavior of this coating was investigated by an-odic polarization and open circuit potential measurement. Its microstructure and composition were observed by scanning electron microscope and energy-dispersive X-ray spectrometry, respectively. The long lasting corrosion performance of coated steels was in-vestigated under the salt fog spray test. From anodic polarization curves and open circuit potential, recycled Al with 8.2 mass% Mg coating performed adequate sacriifcial ability. At 0.40 V, current density of recycled Al with 8.2 mass% Mg alloy coating was about 200 000 times higher than that of pure recycled Al coating, and was about 0.5 times lower than that of Zn coating. The microstruc-ture of recycled Al with 8.2 mass% Mg alloy coating on the steel substrate consisted of Al3Mg2, Al-Fe intermetallic compound and Al matrix. The results from salt fog spray test showed that recycled Al with 8.2 mass% Mg alloy coated steel had similar corrosion resistance ability to Zn coated steel.

  8. Influence of silicon on hot-dip aluminizing process and subsequent oxidation for preparing hydrogen/tritium permeation barrier

    Energy Technology Data Exchange (ETDEWEB)

    Han, Shilei; Li, Hualing; Wang, Shumao; Jiang, Lijun; Liu, Xiaopeng [Energy Materials and Technology Research Institute, General Research Institute for Nonferrous Metals, Beijing 100088 (China)

    2010-04-15

    The development of the International Thermonuclear Experimental Reactor (ITER) requires the production of a material capable of acting as a hydrogen/tritium permeation barrier on low activation steel. It is well known that thin alumina layer can reduce the hydrogen permeation rate by several orders of magnitude. A technology is introduced here to form a ductile Fe/Al intermetallic layer on the steel with an alumina over-layer. This technology, consisting of two main steps, hot-dip aluminizing (HDA) and subsequent oxidation behavior, seems to be a promising coating method to fulfill the required goals. According to the experiments that have been done in pure Al, the coatings were inhomogeneous and too thick. Additionally, a large number of cracks and porous band could be observed. In order to solve these problems, the element silicon was added to the aluminum melt with a nominal composition. The influence of silicon on the aluminizing and following oxidation process was investigated. With the addition of silicon into the aluminum melt, the coating became thinner and more homogeneous. The effort of the silicon on the oxidation behavior was observed as well concerning the suppression of porous band and cracks. (author)

  9. Effect of Initial Iron Content in a Zinc Bath on the Dissolution Rate of Iron During a Hot Dip Galvanizing Process

    Science.gov (United States)

    Lee, Sang Myung; Lee, Suk Kyu; Paik, Doo-Jin; Park, Joo Hyun

    2017-01-01

    The mechanism of iron dissolution and the effect of initial Fe content in a Zn bath on the dissolution rate of iron were investigated using a finger rotating method (FRM). When the initial iron content, [Fe]°, in the zinc bath was less than the solubility limit, the iron content in the zinc bath showed a rapid increase, whereas a moderate increase was observed when [Fe]° was close to the solubility limit. Based on Eisenberg's kinetic model, the mass transfer coefficient of iron in the present experimental condition was calculated to be k M = 1.2 × 10-5 m/s, which was similar to the results derived by Giorgi et al. under industrial practice conditions. A dissolution of iron occurred even when the initial iron content in the zinc bath was greater than the solubility limit, which was explained by the interfacial thermodynamics in conjunction with the morphology of the surface coating layer. By analyzing the diffraction patterns using TEM, the outermost dendritic-structured coating layer was confirmed as FeZn13 (ζ). In order to satisfy the local equilibrium based on the Gibbs-Thomson equation, iron in the dendrite-structured phase spontaneously dissolved into the zinc bath, resulting in the enrichment of iron in front of the dendrite tip. Through the diffusion boundary layer in front of the dendritic-structured layer, dissolved Fe atoms diffused out and reacted with Zn and small amounts of Al, resulting in the formation of dross particles such as FeZn10Al x (δ). It was experimentally confirmed that the smaller the difference between the initial iron content in the zinc bath and the iron solubility limit at a given temperature, the lower the number of formed dross particles.

  10. Effect of Initial Iron Content in a Zinc Bath on the Dissolution Rate of Iron During a Hot Dip Galvanizing Process

    Science.gov (United States)

    Lee, Sang Myung; Lee, Suk Kyu; Paik, Doo-Jin; Park, Joo Hyun

    2017-04-01

    The mechanism of iron dissolution and the effect of initial Fe content in a Zn bath on the dissolution rate of iron were investigated using a finger rotating method (FRM). When the initial iron content, [Fe]°, in the zinc bath was less than the solubility limit, the iron content in the zinc bath showed a rapid increase, whereas a moderate increase was observed when [Fe]° was close to the solubility limit. Based on Eisenberg's kinetic model, the mass transfer coefficient of iron in the present experimental condition was calculated to be k M = 1.2 × 10-5 m/s, which was similar to the results derived by Giorgi et al. under industrial practice conditions. A dissolution of iron occurred even when the initial iron content in the zinc bath was greater than the solubility limit, which was explained by the interfacial thermodynamics in conjunction with the morphology of the surface coating layer. By analyzing the diffraction patterns using TEM, the outermost dendritic-structured coating layer was confirmed as FeZn13 ( ζ). In order to satisfy the local equilibrium based on the Gibbs-Thomson equation, iron in the dendrite-structured phase spontaneously dissolved into the zinc bath, resulting in the enrichment of iron in front of the dendrite tip. Through the diffusion boundary layer in front of the dendritic-structured layer, dissolved Fe atoms diffused out and reacted with Zn and small amounts of Al, resulting in the formation of dross particles such as FeZn10Al x ( δ). It was experimentally confirmed that the smaller the difference between the initial iron content in the zinc bath and the iron solubility limit at a given temperature, the lower the number of formed dross particles.

  11. Investigation of Surface Damage in Forming of High Strength and Galvanized Steel Sheets

    Institute of Scientific and Technical Information of China (English)

    Zhongqi Yu; Yingke Hou; Haomin Jiang; Xinping Chen; Weigang Zhang

    2009-01-01

    Powdering/exfoliating of coatings and scratching are the main forms of surface damage in the forming of galvanized steels and high strength steels (HSS), which result in increased die maintenance cost and scrap rate.In this study, a special rectangular box was developed to investigate the behavior and characteristics of surface damage in sheet metal forming (SMF) processes.U-channel forming tests were conducted to study the effect of tool hardness on surface damage in the forming of high strength steels and galvanized steels (hot-dip galvanized and galvannealed steels).Experimental results indicate that sheet deformation mode influences the severity of surface damage in SMF and surface damage occurs easily at the regions where sheet specimen deforms under the action of compressive stress.Die corner is the position where surface damage initiates.For HSS sheet, surface damage is of major interest due to high forming pressure.The HSS and hot-dip galvanized steels show improved ability of damage-resistance with increased hardness of the forming tool.However, for galvannealed steel it is not the forming tool with the highest hardness value that performs best.

  12. Galvanic Cells

    Science.gov (United States)

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  13. Galvanic Cells

    Science.gov (United States)

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  14. 钢板连续热浸镀铝生产工艺技术%Production technology for continuous hot-dip aluminized steel sheet

    Institute of Scientific and Technical Information of China (English)

    刘灿楼; 李远鹏; 俞钢强; 张启富

    2016-01-01

    Hot-dip aluminized steel sheets are widely used for automotives,appliances and new-energy fields due to its excellent corrosion resistance,high temperature heat resistance,and light and heat reflectivity.The production flow of continuous hot-dip aluminized steel sheet is similar with CGL,but its continuous and stable industrialized production face challenges from the higher bath temperature,poor coating active and strong corrosivity on steel plate and immersion pieces of Al melt.Furnace atmosphere,Aluminum pool management,coating control and cooling af-ter coating are the key techniques for the production of hot dip aluminized steel sheet.Technical difficulties and countermeasures of those key techniques were discussed in detail.%镀铝钢板以其优异的耐蚀性、良好的耐热性(耐高温氧化性)和对光、热的反射性,被广泛应用于汽车、家电和新能源等各个领域。钢板连续热镀铝的生产工艺流程与传统的连续热镀锌基本一样。但由于铝的熔点高、可镀性差以及对钢板和浸入件腐蚀性强等特点,使得钢板连续热镀铝的连续稳定生产面临诸多挑战。还原退火炉气氛控制、镀锅管理技术、镀层控制以及镀后冷却控制技术等是钢板连续热镀铝的关键生产工艺技术,对上述各关键工艺点的技术难点和对策进行详细分析。

  15. The Effect of the Thickness of Fe2 Al5 Phase Layer at Fe/Al Interface on the Mechanics Behavior of Hot Dip Aluminizing Coating

    Institute of Scientific and Technical Information of China (English)

    XIA Yuan; YU Sheng-xue; CHEN Ling; CUI Rui-yi; YAO Mei

    2004-01-01

    Hot Dip Aluminized Coatings with different thickness were prepared on Q235 steel in aluminum solutions with different temperature for certain time. Through tensile tests and in-situ SEM observations, the effect of the coating's microstructure on the tensile strength of the samples was studied. It was disclosed at certain aluminum solution temperature,transaction layers mainly composed of Fe2 Al5 phase got thicker with time prolonging, and this changed initial crack's extending direction from parallel with to vertical with stretching direction. The change in crack direction decreased tensile strength of samples, thus made the coating easy to break. It was concluded that the existence of thick Fe2 Al5 phase layer was the basic reason for the lowering of tensile strength of the coating.

  16. High-performance varistors simply by hot-dipping zinc oxide thin films in Pr6O11: Influence of temperature

    Science.gov (United States)

    Wang, Yang; Peng, Zhijian; Wang, Qi; Wang, Chengbiao; Fu, Xiuli

    2017-01-01

    High-performance ZnO-Pr6O11 thin-film varistors were fabricated simply by hot-dipping oxygen-deficient zinc oxide thin films in Pr6O11 powder. The films had a composition of ZnO0.81 and a thickness of about 200 nm, which were deposited by radio frequency magnetron sputtering a sintered zinc oxide ceramic target. Special attention was paid on the temperature dependence of the varistors. In 50 min with hot-dipping temperature increased from 300–700 °C, the nonlinear coefficient (α) of the varistors increased, but with higher temperature it decreased again. Correspondingly, the leakage current (IL) decreased first and then increased, owing mainly to the formation and destroying of complete zinc oxide/Pr6O11 grain boundaries. The breakdown field (E1mA) decreased monotonously from 0.02217 to 0.01623 V/nm with increasing temperature (300–800 °C), due to the decreased number of effective grain boundaries in the varistors. The varistors prepared at 700 °C exhibited the optimum nonlinear properties with the highest α = 39.29, lowest IL = 0.02736 mA/cm2, and E1mA = 0.01757 V/nm. And after charge-discharge at room temperature for 1000 times, heating at 100 or 250 °C for up to 100 h, or applying at up to 250 °C, the varistors still performed well. Such nanoscaled thin-film varistors will be very promising in electrical/electronic devices working at low voltage. PMID:28155890

  17. Influence of stripping and cooling atmospheres on surface properties and corrosion of zinc galvanizing coatings

    Science.gov (United States)

    Yasakau, K. A.; Giner, I.; Vree, C.; Ozcan, O.; Grothe, R.; Oliveira, A.; Grundmeier, G.; Ferreira, M. G. S.; Zheludkevich, M. L.

    2016-12-01

    In this work the influence of stripping/cooling atmospheres used after withdrawal of steel sheet from Zn or Zn-alloy melt on surface properties of Zn (Z) and Zn-Al-Mg (ZM) hot-dip galvanizing coatings has been studied. The aim was to understand how the atmosphere (composed by nitrogen (N2) or air) affects adhesion strength to model adhesive and corrosive behaviour of the galvanized substrates. It was shown that the surface chemical composition and Volta potential of the galvanizing coatings prepared under the air or nitrogen atmosphere are strongly influenced by the atmosphere. The surface chemistry Z and ZM surfaces prepared under N2 contained a higher content of metal atoms and a richer hydroxide density than the specimens prepared under air atmosphere as assessed by X-ray photoelectron spectroscopy (XPS). The induced differences on the microstructure of the galvanized coatings played a key role on the local corrosion induced defects as observed by means of in situ Atomic force microscopy (AFM). Peel force tests performed on the substrates coated by model adhesive films indicate a higher adhesive strength to the surfaces prepared under nitrogen atmosphere. The obtained results have been discussed in terms of the microstructure and surface chemical composition of the galvanizing coatings.

  18. Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

    Science.gov (United States)

    Delaunois, F; Tosar, F; Vitry, V

    2014-06-01

    Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Effect of zinc crystals size on galvanized steel deformation and electrochemical behavior

    Directory of Open Access Journals (Sweden)

    José Daniel Culcasi

    2009-09-01

    Full Text Available Hot-dip galvanized steel sheets with different spangle sizes were deformed by means of rolling and tension. The change of preferential crystallographic orientation and of superficial characteristics due to the deformation was analyzed by means of both X-rays diffraction and optical and scanning electronic microscopy. A correlation between such changes and the involving deformation modes was intended to be done and the spangle size influence on these modes was studied. Coating reactivity change due to the deformation was investigated by means of quasi-steady DC electrochemical tests. The results allow to infer that, in great spangle samples, the main deformation mechanism is twinning whereas in small spangle ones, pyramidal slip systems happen as well. The increase of the reactivity with the deformation is greater in tension than in rolling and it is more important in small than in great spangle samples.

  20. Post treatment of silane and cerium salt as chromate replacers on galvanized steel

    Institute of Scientific and Technical Information of China (English)

    KONG Gang; LU Jintang; WU Haijiang

    2009-01-01

    A complex film on hot-dip galvanized steel sheet (HDG) was prepared by immersing the sheet in 0.1wt.% Ce(NO3)3 solution and 5vol.% silane solution in turn. The corrosion protection of the complex film was evaluated by potentiodynamic linear polarization(LPR), electrochemical impendence spectra (EIS) and natural salt spray (NSS) tests and compared with that of single cerium film and silane film. The results showed that, the presence of these films on the zinc coating hindered corrosion reaction by reducing the rate of both anodic and cathodic reaction in the corrosion process, and the corrosion protection of the complex film was much better than that of single cerium film or silane film and closed to that of chromate film, because the polarization resistance Rp and electrochemical impendence were increased markedly. Microstructure and chemical composition of these pretreated films were also investigated by scanning electron microscopy (SEM) and AES.

  1. TEM analysis and wear resistance of the ceramic coatings on Q235 steel prepared by hybrid method of hot-dipping aluminum and plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lu Lihong [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Science and Research Department, Chinese People' s Armed Police Academy, Langfang 065000 (China); Zhang Jingwu [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Shen Dejiu, E-mail: sdj217@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Wu Lailei; Jiang Guirong [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Li Liang [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2012-01-25

    Highlights: Black-Right-Pointing-Pointer Transmission electron microscopy (TEM) was firstly used to analyze the phase composition of the ceramic coatings. Black-Right-Pointing-Pointer The phase composition of the ceramic coatings is mainly amorphous phase and crystal Al{sub 2}O{sub 3} oxides. Black-Right-Pointing-Pointer The cross-section micro-hardness of the treated samples was investigated, the hardness of the ceramic coatings is about HV1300. Black-Right-Pointing-Pointer The wear resistance of the PEO samples is about 3 times higher than that of the heat treated 45 steel. - Abstract: The hybrid method of PEO and hot-dipping aluminum (HDA) was employed to deposit composite ceramic coatings on the surface of Q235 steel. The composition of the composite coatings was investigated with X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The cross-section microstructure and micro-hardness of the treated specimens were investigated and analyzed with scanning electron microscopy (SEM) and microscopic hardness meter (MHM), respectively. The wear resistance of the ceramic coatings was investigated by a self-made rubbing wear testing machine. The results indicate that metallurgical bonding can be observed between the ceramic coatings and the steel substrate. There are many micro-pores and micro-cracks, which act as the discharge channels and result of quick and non-uniform cooling of melted sections in the plasma electrolytic oxidation ceramic coatings. The phase composition of the ceramic coatings is mainly composed of amorphous phase and crystal Al{sub 2}O{sub 3} oxides. The crystal Al{sub 2}O{sub 3} phase includes {kappa}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3} and {beta}-Al{sub 2}O{sub 3}. The grain size of the {kappa}-Al{sub 2}O{sub 3} crystal is quite non-uniform. The hardness of the ceramic coatings is about HV1300 and 10 times higher than that of the Q235 substrate, which was favorable to the better wear resistance of the ceramic

  2. Galvanized Pot Wall Detection System Research and Development%热镀锌锅壁板检测系统的研究与开发

    Institute of Scientific and Technical Information of China (English)

    刘双源; 王玉增; 韩婧茹; 李广亚

    2014-01-01

    In the hot-dip galvanizing pot for the domestic gaps siding detection, design the corresponding de-tection system. Detection system, based on serial communication between PC and PLC, can quickly and ac-curately complete the task of data acquisition, collecting corrosion on the hot-dip galvanizing pot wall, and, can analyze and calibrate the detector data, at last, output the corrosion statements and surface morphology of corrosion. Experiments show that the detection system safe, reliable, convenient, and has high accuracy, capable of field testing tasks.%针对国内在热镀锌锅壁板检测方面的空白,设计了相应的检测系统。检测系统基于上位机与PLC之间的串口通讯,能够快速精确的完成对热镀锌锅壁板腐蚀情况的数据采集,并能够对检测数据进行分析校准,最终生成输出腐蚀报表及腐蚀曲面形貌。实验表明,检测系统安全可靠、方便快捷,并且有较高的精度,能够胜任现场检测的任务。

  3. Research on High Temperature Oxidation Resistance of Hot-dip Aluminized Steel%热浸镀铝钢抗高温氧化腐蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    吴笛

    2012-01-01

    Considering high temperature oxidation resistance of hot-dip aluminized steel, the experimental study on it at 900℃ and for 100h and through weight gain was discontinuously implemented. The results show that the oxidation by weight per unit area of hot-dip aluminized steel is a quarter of general carbon steel, and the oxide film which making up this deposit together with matrix and diffusion zone has excellent high temperature oxidation resistance.%在实验室条件下通过900C、100h的不连续氧化增重试验研究了热浸镀铝钢的抗高温氧化腐蚀性能,结果表明,热浸镀铝钢单位面积氧化增重量为普通碳钢的1/4,其中浸镀层由表面的氧化膜、母体和扩散区组成,氧化膜具有优良的抗高温氧化性能.

  4. Coating Galvanized Steel

    Science.gov (United States)

    1989-06-01

    of special treatments other than weathering: "The "home cure" type of treatments such as washing the surface with vinegar , acetic acid, cider , copper...bonding of topcoats to smooth galvanizing have lead to such practices as washing with vinegar , washing with copper sulfate solution, or weathering before

  5. Cross-Beam Laser Joining of AA 6111 to Galvanized Steel in a Coach Peel Configuration

    Science.gov (United States)

    Yang, Guang; Mohammadpour, Masoud; Yazdian, Nima; Ma, Junjie; Carlson, Blair; Wang, Hui-Ping; Kovacevic, Radovan

    2017-06-01

    Cross-beam laser joining of aluminum alloy 6111 to hot-dip galvanized steel in the coach-peel configuration was investigated with the addition of AA 4047 filler wire. The filler material was not only brazed onto the galvanized steel but also partially fusion-welded with the aluminum panel. Through adjusting the laser power to 3.4 kW, a desirable wetting and spreading of filler wire on both panel surfaces could be achieved, and the thickness of intermetallic layer in the middle section of the interface between the weld bead and steel was less than 2 μm. To better understand the solid/liquid interfacial reaction at the brazing interface, two rotary Gaussian heat source models were introduced to simulate the temperature distribution in the molten pool by using the finite element method. Joint properties were examined in terms of microstructure and mechanical properties. During the tensile test, the fracture of coupons took place at the aluminum side rather than along the interface between the intermetallic layer and steel panel. No failure occurred during the three-point bending test.

  6. REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING

    Directory of Open Access Journals (Sweden)

    Mônica Marques Caetano de Lima

    2013-06-01

    Full Text Available Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat these scraps to remove zinc layer using a thermal treatment process. The samples were fed to a rotative furnace in an inert ambient. It was tested the hot dip galvanized and eletrogalvanized scraps, varying the zinc coating weight between 20g/m2 and 150g/m2, temperature between 700°C and 900°C and time between 3 minutes and 10 minutes. Considering these conditions, it is verified that more than 70% of the zinc layer is removed at 700°C, in 10 minutes. Dust captured is about 60% of metallic zinc and 40% as zinc oxide. Based on these results, the recycling of BOF sludge can be feasible to the ironmaking process.

  7. Microscopic analysis and simulation of check-mark stain on the galvanized steel strip

    Science.gov (United States)

    So, Hongyun; Yoon, Hyun Gi; Chung, Myung Kyoon

    2010-11-01

    When galvanized steel strip is produced through a continuous hot-dip galvanizing process, the thickness of adhered zinc film is controlled by plane impinging air gas jet referred to as "air-knife system". In such a gas-jet wiping process, stain of check-mark or sag line shape frequently appears. The check-mark defect is caused by non-uniform zinc coating and the oblique patterns such as "W", "V" or "X" on the coated surface. The present paper presents a cause and analysis of the check-mark formation and a numerical simulation of sag lines by using the numerical data produced by Large Eddy Simulation (LES) of the three-dimensional compressible turbulent flow field around the air-knife system. It was found that there is alternating plane-wise vortices near the impinging stagnation region and such alternating vortices move almost periodically to the right and to the left sides on the stagnation line due to the jet flow instability. Meanwhile, in order to simulate the check-mark formation, a novel perturbation model has been developed to predict the variation of coating thickness along the transverse direction. Finally, the three-dimensional zinc coating surface was obtained by the present perturbation model. It was found that the sag line formation is determined by the combination of the instantaneous coating thickness distribution along the transverse direction near the stagnation line and the feed speed of the steel strip.

  8. Development of Zn-Al-Cu coatings by hot dip coated technology: preparation and characterization; Obtencion y caracterizacion de recubrimientos Zn-Al-Cu por inmersion en caliente sobre aceros de bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, J.; Barba, A.; Hernandez, M. A.; Salas, J.; Espinoza, J. L.; Denova, C.; Torres-Villasenor, G.; Conde, A.; Covelo, A.; Valdez, R.

    2013-07-01

    In the present study, research concerning Zn-Al-Cu coatings on low carbon steels has been conducted in order to characterize different properties obtained by a hot-dip coated process. The results include preparation procedure as well as the processing parameters of the coatings. The obtained coatings were subjected to a cold rolling process followed by an anneal heat treatment at different temperatures and under different time conditions. The structural characteristics of coatings have been investigated by optical and electron microscopy. The mechanical properties were obtained by using micro-hardness testing, deep drawing and wear tests whereas chemical analyses were carried out using the SEM/EDAX microprobe. The corrosion properties were achieved by using a salt spray fog chamber and potentiodynamic tests in a saline solution. The coatings are resistant to corrosion and wear in the presence of sodium chloride, therefore, the coatings could be an attractive alternative for application in coastal areas, and adequate wear adhesive resistance. (Author)

  9. 低碳钢热浸镀铝微弧氧化陶瓷层厚度研究%Thickness of Micro- Arc Oxided Ceramic Layer on Hot Dip Aluminized Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    高殿奎; 沈德久; 王玉林

    2001-01-01

    研究了影响低碳钢热浸镀铝微弧氧化陶瓷层生长厚度的因素,指出了获得最大厚度的氧化时间并对其原因进行了分析。结果表明,影响陶瓷层厚度的主要因素是氧化时间,热浸镀最佳温度为720~730 ℃。%The factors affecting the thickness of micro- arc oxided ceramic layer on hot dip aluminized low carbon steel were discussed.The experimental results showed that the predominant affecting factor was time for oxidation.

  10. Coat Structure Analysis and Formation Mechanismof Deformation 12CrMoV Steel Hot-Dip Aluminizing%形变12CrMOV钢热浸铝的镀层组织及形成机制

    Institute of Scientific and Technical Information of China (English)

    高聿为

    2000-01-01

    The coat microstructures of deformation 12CrMoV steel hot-dip aluminizing were analyzed by optical mi-croscope, TEM and X-ray diffraction, and the formation mechanism was discussed in the paper%用金相显微镜、透射电子显微镜及X射线衍射仪对形变热浸镀铝的镀层微观组织进行了分析,并探讨了其形成机制。所得结果对完善形变钢热浸镀铝的镀层组织及形成机制提供一定的参考依据,对制定形变件的浸镀工艺也有一定的指导意义。

  11. Effect of Bi on Microstructure and Thickness of Hot-dip Aluminizing Coating on Magnesium Alloy%Bi对镁合金热浸镀铝镀层组织和厚度的影响

    Institute of Scientific and Technical Information of China (English)

    薛寒松; 陈祖权; 向军军

    2013-01-01

    采用热浸镀方法在AZ31镁合金表面镀覆一层铝合金层.利用光学显微镜和配有能谱分析的扫描电镜等对镀层微观组织、元素分布等进行了研究;测定了试样在不同浸镀条件下的镀层厚度.结果表明:镀液添加Bi后,在浸镀温度不变情况下,镀层厚度增加速度加快,过渡层厚度变大,镀层中粗大的树枝晶增多,但是Bi在镀层中含量极少.通过对试验结果分析得出:Bi元素对Mg、Al液态互扩散具有显著的促进作用,使得镀层形成速度加快,但是也造成镀层组织粗大.%The aluminum coating on AZ31 Mg alloy surface was prepared by hot dipping process. The microstructure of coating, distribution of element were studied by OM and SEM. The thickness of the coating was measured. The results show that after adding Bi into the hot-dipping solution, with the dipping temperature being constant, the increasing rate of the thickness of the coating becomes higher, the thickness of intermediate layer and the amount of coarse dendrite increases, but the amount of Bi in coating is extremely low. An analysis on the result of experiment shows that Bi can promote liquid mutual diffusion between Mg and Al, speed up the formation of coating, but also causes the formation of coarse structure.

  12. Imposed currents in galvanic cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current

  13. Imposed currents in galvanic cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current ag

  14. Research Progress of Hot-dip Zn-Al-X Alloy Coatings and Processes%热浸Zn-Al-X合金镀层及工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    刘继拓; 贺志荣; 何应; 解凯

    2013-01-01

    The effects of the alloy element Mg, Bi, Sn, RE, etc. on the microstructure and properties of Zn-Al alloy coatings are discussed. The microstructure, properties, application fields and process development of Zn-Al-RE, Zn-Al-Mg, Zn-Al-Si, Zn-Al-Mg-Si and Zn-Al-Sn-Bi alloy coatings are introduced. The existing problems at present and research directions in the future of the technology for the hot-dip Zn-Al based alloy coatings are pointed out.%论述了合金元素Mg、Bi、Sn、RE等对Zn-Al合金镀层组织性能的影响,介绍了Zn-Al-RE、Zn-Al-Mg、Zn-Al-Si、Zn-Al-Mg-Si和Zn-Al-Sn-Bi等合金镀层的组织结构、性能特点、应用场合和工艺发展,指出了热浸Zn-Al基合金镀层技术目前存在的问题和研究方向.

  15. Imposed currents in galvanic cells

    OpenAIRE

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M. Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current against an external load, but also operation in two modes which require a net input of electrical energy: (i) the electrolytic charging mode, where a negative current is imposed to generate a voltage...

  16. Effect of silicate pretreatment, post-sealing and additives on corrosion resistance of phosphated galvanized steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sodium silicate (water glass) pretreatment before phosphating, silicate post-sealing after phosphating and adding silicate to a traditional phosphating solution were respectively carried out to obtain the improved phosphate coatings with high corrosion resistance and coverage on hot-dip galvanized(HDG) steel. The corrosion resistance, morphology and chemical composition of the coatings were investigated using neutral salt spray(NSS) tests, scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS). The results show that pretreatment HDG steel with silicate solutions, phosphate coatings with finer crystals and higher coverage are formed and the corrosion resistance is enhanced. Adding silicate to a traditional phosphating solution, the surface morphology of the coatings is nearly unchanged. The corrosion resistance of the coatings is mainly dependent on phosphating time.Phosphating for a longer time (such as 5 min), the corrosion resistance, increasing with concentration of silicate, is improved significantly. Post-sealing the phosphated HDG steel with silicate solutions, the pores among the zinc phosphate crystals are sealed with the films containing Si, P, O and Zn and the continuous composite coatings are formed. The corrosion resistance of the composite coatings, related to the pH value, contents of hydrated gel of silica and Si2O52- and post-sealing time, is increased markedly. The improved coatings with optimal corrosion resistance are obtained for phosphating 5 min and post-sealing with 5 g/L silicate solution for 10 min.

  17. Hot dip aluminizing on 17-4PH stainless steel and its high-temperature oxidation resistance%17-4PH不锈钢热浸镀铝及其高温耐氧化性能

    Institute of Scientific and Technical Information of China (English)

    王院生; 熊计; 王均; 李海丰; 张太平; 石树坤

    2011-01-01

    Hot-dip aluminizing and diffusion annealing were carried out on 17-4PH stainless steel. The microstructure and microhardness of the coating and its high-temperature oxidation resistance were studied. The results showed that the coating consists of three layers including rich aluminum layer, alloy layer and substrate layer.The major phase of the alloy layer is Fe2Al5. After diffusion annealing treatment at 950 ℃ for 1 h, the rich aluminum layer transforms into the alloy layer completely with a thickness of ca. 100 μm. The alloy layer can divide into an inner diffusion layer and an outer diffusion layer. The inner diffusion layer is ca.40 μm thick and its main phase is Fe3Al.The outer diffusion layer is mainly composed of FeAl. The microhardness of alloy layer reduces gradually from the surface to the substrate and the maximum value is 714 HV. After hot dip aluminizing, the high-temperature oxidation resistance of 17-4PH stainless steel is greatly improved. The high-temperature oxidation resistance of 17-4PH stainless steel is approximately seven times that of the common one at 1 000 ℃. During the oxidation process, r-A12O3 in the surface layer and intermetallic compounds FeAl and Fe3Al play a role in the high-temperature oxidation resistance.%在17-4PH不锈钢上热浸镀铝,然后进行扩散退火处理.研究了热浸镀铝层的显微组织和显微硬度的变化,并考察了其高温耐氧化性能.结果表明:17-4PH不锈钢热浸镀铝后表面分为富铝层、合金层、基体层等3层,合金层主要相为Fe2Al5.经950℃.1 h的扩散处理后,富铝层全部转变为合金层,厚度约为100 μM,且分为内扩散层与外扩散层.内扩散层厚度约为40 μm,主要相为Fe3Al;外扩散层主要相为FeAl.合金层的显微硬度从表面到基体逐渐降低,表面显微硬度最高达到714 HV.17-4PH不锈钢经热浸镀铝后,其高温耐氧化性能显著提高.在1000℃,热浸镀铝件的高温耐氧化性能约是未镀铝件的7倍.

  18. 热浸镀铝锌硅镀层云纹缺陷的分析及抑制%Analysis and Control of Coating Ripple on the Hot-Dip Galvalume Coating

    Institute of Scientific and Technical Information of China (English)

    常崇民; 陈立章

    2012-01-01

    The defects of transverse coating ripple and longitude coating ripple on the hot-dip galvalume coating produced by thin slab continous casting-rolling process were analyzed by using OM and SEM-EDS. Comprehensively, air knife-pressure, gap of air knife, angle of air knife, the temperature of zinc liquid, the temperature of steel strip in zinc pot are the main reasons of coating ripple on the galvalume coating. Longitude coating ripple is caused by lower air knife pressure and higher temperature of zinc liquid. Higher air knife pressure and wider gap of air knife lead to transverse coating ripple. The homogeneity coating thickness, spangles and shine can be achieved by means of controlling the process parameters to ensure the shake of strip steel under 3 mm at certain temperatre.%对采用薄板坯连铸连轧工艺生产的热浸镀铝锌硅产品镀层横向云纹缺陷和纵向云纹缺陷进行了表面和截面结构的分析。结果表明,产生的云纹缺陷与气刀工作压力、气刀工作距离、气刀喷吹角度、锌液温度和钢板入锌锅温度有关;气刀工作压力过低及锌液温度过高时,易形成纵向云纹缺陷。气刀工作压力过大,气刀间距相应变大,形成镀层横向云纹缺陷;在一定温度下,调整各项参数将钢带抖动控制在3mm以下时,可以获得均匀的镀层厚度、表面锌花尺寸和色泽。

  19. Application of artificial neural network and adaptive neuro-fuzzy inference system to investigate corrosion rate of zirconium-based nano-ceramic layer on galvanized steel in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Mousavifard, S.M. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Attar, M.M., E-mail: attar@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ghanbari, A. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dadgar, M. [Textile Engineering Department, Neyshabur University, Neyshabur (Iran, Islamic Republic of)

    2015-08-05

    Highlights: • Film formation of Zr-based conversion coating under different conditions was investigated. • We study the effect of some parameters on anticorrosion performance of conversion coating. • Optimization of processing conditions for surface treatment of galvanized steel was obtained. • Modeling and predicting corrosion current density of treated surfaces was performed using ANN and ANFIS. - Abstract: A nano-ceramic Zr-based conversion solution was prepared and optimization of Zr concentration, pH, temperature and immersion time for the treatment of hot-dip galvanized steel (HDG) was performed. SEM microscopy was utilized to investigate the microstructure and film formation of the layer and the anticorrosion performance of conversion coating was studied using polarization test. Artificial intelligence systems (ANN and ANFIS) were applied on the data obtained from polarization test and the models for predicting corrosion current density values were attained. The outcome of these models showed proper predictability of the methods. The influence of input parameters was discussed and the optimized conditions for Zr-based conversion layer formation on the galvanized steel were obtained as follows: pH 3.8–4.5, Zr concentration of about 100 ppm, ambient temperature and immersion time of about 90 s.

  20. Al-5Ti-B-RE细化剂对热浸渗铝层的组织与性能的影响%The effect of Al-5Ti-B-RE refiner on the microstructure and property of the hot dip aluminized coatings

    Institute of Scientific and Technical Information of China (English)

    李安敏; 胡武; 王海超; 李松浩

    2013-01-01

    In order to study the effects of refiner on the microstructure and the high temperature oxi-dation resistance of the hot dip aluminized coatings , the hot dip aluminized coatings on the surface of Q235 steel were prepared by flux method , and Al-5Ti-B-RE refiner was added in the aluminum melt.The microstructure of aluminized coating was analyzed by X-ray diffractometer and scanning e-lectron microscope , and the resistance to high temperature oxidation of aluminized coating was tested by the oxidation weight increase method .The results showed that all the hot dip aluminized coatings were formed by surface layer and alloy layer;the thickness of the coating decreased when refiner was added , and the needles ( FeAl3 ) in the surface layer were refined and the dentate alloy layer became thiner, close and less bifurcation;with the increase of refiner , the high temperature oxidation resist-ance of the aluminized steel increased mitially and then decreased , and the hot dip aluminizing with 0.3%Al-5Ti-B-RE refiner was the best.%采用熔剂法在Q235钢表面热浸渗铝,并在铝熔体中添加Al-5Ti-B-RE中间合金细化剂,利用金相显微镜、X射线衍射仪、扫描电子显微镜等研究渗铝层的显微组织,运用氧化增重法测试渗铝钢的抗高温氧化性能,以研究细化剂对热浸渗铝层的显微组织和抗高温氧化性能的影响。结果表明:渗铝层都是由表面层和合金层组成;铝液中加入细化剂后,表面层和合金层的厚度都降低,表面层的针状物( FeAl3)细化,合金层的齿状整齐,齿峰分叉减少;随着细化剂含量的增加,渗铝钢的抗高温氧化性能先增加后降低,添加0.3%(质量百分比)细化剂的渗铝钢的抗高温氧化性能最好。

  1. Electrocatalysts Prepared by Galvanic Replacement

    OpenAIRE

    Athanasios Papaderakis; Ioanna Mintsouli; Jenia Georgieva; Sotiris Sotiropoulos

    2017-01-01

    Galvanic replacement is the spontaneous replacement of surface layers of a metal, M, by a more noble metal, Mnoble, when the former is treated with a solution containing the latter in ionic form, according to the general replacement reaction: nM + mMnoblen+ → nMm+ + mMnoble. The reaction is driven by the difference in the equilibrium potential of the two metal/metal ion redox couples and, to avoid parasitic cathodic processes such as oxygen reduction and (in some cases) hydrogen evolution too...

  2. Galvanic corrosion of selected dental alloys.

    Science.gov (United States)

    Karov, J; Hinberg, I

    2001-03-01

    Samples prepared from three different amalgam brands were coupled to two gold alloys and orthodontic brackets. In the resulting galvanic cells, the amalgam coupled to gold were anodic, exhibiting galvanic current densities about one order of magnitude higher than the uncoupled corrosion current densities of 0.2-0.5 microA. Coupling amalgams to orthodontic brackets resulted in galvanic current densities of the same magnitude as the uncoupled samples. Corrosion current densities at the anode were found to be up to six times higher than the measured galvanic current densities. Brushing caused transient increases in galvanic current densities that decayed within 100 s to the previous steady state levels. Brushing of amalgam/bracket couples, caused an anodic peak followed by brief polarization reversal during which the brackets were anodic.

  3. Electrocatalysts Prepared by Galvanic Replacement

    Directory of Open Access Journals (Sweden)

    Athanasios Papaderakis

    2017-03-01

    Full Text Available Galvanic replacement is the spontaneous replacement of surface layers of a metal, M, by a more noble metal, Mnoble, when the former is treated with a solution containing the latter in ionic form, according to the general replacement reaction: nM + mMnoblen+ → nMm+ + mMnoble. The reaction is driven by the difference in the equilibrium potential of the two metal/metal ion redox couples and, to avoid parasitic cathodic processes such as oxygen reduction and (in some cases hydrogen evolution too, both oxygen levels and the pH must be optimized. The resulting bimetallic material can in principle have a Mnoble-rich shell and M-rich core (denoted as Mnoble(M leading to a possible decrease in noble metal loading and the modification of its properties by the underlying metal M. This paper reviews a number of bimetallic or ternary electrocatalytic materials prepared by galvanic replacement for fuel cell, electrolysis and electrosynthesis reactions. These include oxygen reduction, methanol, formic acid and ethanol oxidation, hydrogen evolution and oxidation, oxygen evolution, borohydride oxidation, and halide reduction. Methods for depositing the precursor metal M on the support material (electrodeposition, electroless deposition, photodeposition as well as the various options for the support are also reviewed.

  4. Batch By Batch Longitudinal Emittance Blowup MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Jaussi, M; Molendijk, J

    2012-01-01

    The transverse bunch emittance increases significantly at 450 GeV from the time of injection till the ramp due to IBS. By selectively blowing up the longitudinal emittance of the incoming batch at each injection, it should be possible to reduce the transverse emittance growth rates due to IBS. An MD was conducted on April 22nd 2012 to test the feasibility and performance of the batch-by-batch longitudinal emittance blowup. There were three main goals during the MD. First, to test the developed hardware, firmware, and software for the batch-by-batch blowup. Then, to measure the transverse emittance growth rates of blown-up and "witness" batches to quantify any improvement, and finally to test the ALLInjectSequencer class, which deals with the complicated gymnastics of introducing or masking the new batch to various RF loops.

  5. Behavioral modeling and analysis of galvanic devices

    Science.gov (United States)

    Xia, Lei

    2000-10-01

    A new hybrid modeling approach was developed for galvanic devices including batteries and fuel cells. The new approach reduces the complexity of the First Principles method and adds a physical basis to the empirical methods. The resulting general model includes all the processes that affect the terminal behavior of the galvanic devices. The first step of the new model development was to build a physics-based structure or framework that reflects the important physiochemical processes and mechanisms of a galvanic device. Thermodynamics, electrode kinetics, mass transport and electrode interfacial structure of an electrochemical cell were considered and included in the model. Each process of the cell is represented by a clearly-defined and familiar electrical component, resulting in an equivalent circuit model for the galvanic device. The second step was to develop a parameter identification procedure that correlates the device response data to the parameters of the components in the model. This procedure eliminates the need for hard-to-find data on the electrochemical properties of the cell and specific device design parameters. Thus, the model is chemistry and structure independent. Implementation issues of the new modeling approach were presented. The validity of the new model over a wide range of operating conditions was verified with experimental data from actual devices. The new model was used in studying the characteristics of galvanic devices. Both the steady-state and dynamic behavior of batteries and fuel cells was studied using the impedance analysis techniques. The results were used to explain some experimental results of galvanic devices such as charging and pulsed discharge. The knowledge gained from the device analysis was also used in devising new solutions to application problems such as determining the state of charge of a battery or the maximum power output of a fuel cell. With the new model, a system can be designed that utilizes a galvanic device

  6. The influence of Si and P in steels on the galvanizing behavior; Zum Einfluss von Si und P auf das Verzinkungsverhalten von Baustaehlen

    Energy Technology Data Exchange (ETDEWEB)

    Katzung, W. [Inst. fuer Stahlbau, Leipzig (Germany); Rittig, R.

    1997-12-01

    The galvanizing behavior of 40 structural steels in current use was investigated in relation to the complex influence of the Si/P content under conditions that are usual in the hot dip galvanizing industry (440/450/460 C, 5/10/15 min immersion time). The effect of P on the increase of coating thickness on steels with 0.01 to 0.40% Si begins to be perceptible at > 0.020% P. The influence of P increases with decreasing Si content of the steels and decreasing temperature of the melt. In steels with {<=} 0.12% Si, an increased P content causes a shift of the thickness maxima in the temperature range from 440 to 450 C, such as is otherwise typical of steels of 0.12% to 0.28% Si with < 0.020% P. Zinc coatings on steels with the critical P/Si content (0 to 0.20% Si/> 0.020% P) as a rule are more unstable. With increased immersion time at the temperature stated above, floating away of the {zeta} phase into the zinc melt may occur. This could also be observed with Sandelin steels in the most critical Si range (0.07 to 0.10%) with < 0.020% P, with an immersion time of 15 min. It is possible to reduce the thickness of zinc coatings by adding small amounts of Al to the zinc melt (< 0.03%). This effect of Al at a concentration that is below what is required for the known inhibitory action by the formation of an thin Fe{sub 2}Al{sub 5}- or Al-containing {delta}{sub 1} film on the steel surface is attributed to the instability of the {zeta} phase, a proportion of which floats away into the zinc melt. (orig.)

  7. COMPLEX EVALUATION OF WORKING CONDITIONS IN GALVANIC WORKSHOPS

    OpenAIRE

    A. M. Lazarenkov; S. A. Khoreva; V. V. Melnichenko

    2013-01-01

    The results of complex evaluation of working conditions in galvanic workshops, and based on research of industrial environmental factors jobs are given. The hygienic overview of working conditions classification in working stations of galvanic workshops is given.

  8. Epitaxial growth by monolayer restricted galvanic displacement

    Directory of Open Access Journals (Sweden)

    Vasilić Rastko

    2012-01-01

    Full Text Available The development of a new method for epitaxial growth of metals in solution by galvanic displacement of layers pre-deposited by underpotential deposition (UPD was discussed and experimentally illustrated throughout the lecture. Cyclic voltammetry (CV and scanning tunneling microscopy (STM are employed to carry out and monitor a “quasi-perfect”, two-dimensional growth of Ag on Au(111, Cu on Ag(111, and Cu on Au(111 by repetitive galvanic displacement of underpotentially deposited monolayers. A comparative study emphasizes the displacement stoichiometry as an efficient tool for thickness control during the deposition process and as a key parameter that affects the deposit morphology. The excellent quality of layers deposited by monolayer-restricted galvanic displacement is manifested by a steady UPD voltammetry and ascertained by a flat and uniform surface morphology maintained during the entire growth process.

  9. 77 FR 28404 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2012-05-14

    ... COMMISSION Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1... retarded, by reason of imports from Mexico of galvanized steel wire, provided for in subheadings 7217.20.30... galvanized steel wire from China and Mexico were sold at LTFV within the meaning of 733(b) of the Act (19...

  10. 76 FR 29266 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-05-20

    ... COMMISSION Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1... injured by reason of imports from China and Mexico of galvanized steel wire, provided for in subheading... subsidized imports of galvanized steel wire from China and Mexico. Accordingly, effective March 31, 2011,...

  11. Wire beam electrode technique for investigating galvanic corrosion behavior of galvanized steel-spot defect%丝束电极研究镀锌层存在点缺陷的锌/钢电偶腐蚀行为

    Institute of Scientific and Technical Information of China (English)

    张大磊; 王伟; 金有海; 唐晓; 李焰

    2011-01-01

    采用3种不同配置比例的锌/碳钢异材质丝束电极,模拟镀锌层存在不同大小点缺陷时的热浸镀钢,研究锌/钢电偶在不同腐蚀阶段的电位和电流密度分布.结果表明,在钢丝与锌丝面积比为1:120、9:112和25:96的3种情况下,锌丝均能给钢丝提供足够的阴极保护,且锌丝之间存在明显的电位、电流分布不均现象,主要阳极区先随机地在邻近钢丝的锌丝区域内转移,而后逐渐向远端锌丝扩展;钢丝之间也存在电化学参数分布不均一现象,钢丝在受到保护的同时表面会有氢原子析出,且随着阴、阳极面积比的增大,析氢电流密度逐渐减小.%Three kinds of wire beam electrodes(WBE) composed of zinc and mild steel wires were developed, which were used to simulate hot-dip galvanized steel with spot coating defect at different dimensions, to obtain the spatial distributions of potential and current density and their variations with time during the galvanic corrosion. The results show that the zinc wires within WBEs can provide enough cathodic protection to steel wires after immersed in seawater, with surface area ratio of zinc wires to steel wires as 1:120, 9:112, and 25:96, respectively. The potential and current density distributions are found to be inhomogeneous among zinc wires; firstly, the main anodic areas shift randomly among the zinc wires adjacent to steel wires, then transfer to the direction away from steel wires, and finally occur on the zinc wires farther. The similar heterogeneous phenomenon also appears on steel wires surface on which hydrogen evolution may take part in the cathodic process occurred. Meanwhile, the current density of water molecule reduction reaction decreases with the ratio of the surface area of steel wires to zinc wires increasing.

  12. Galvanic cells including cobalt-chromium alloys.

    Science.gov (United States)

    Gjerdet, N R

    1980-01-01

    Galvanic cells may be created when dentures made of cobalt-chromium alloys are placed on teeth with metallic restorations. The power of such cells was evaluated in an in vitro galvanic using amalgams, gold alloy, and nickel-chromium alloys. The amalgams and one of the nickel-chromium alloys revealed high corrosion currents when placed in contact with cobalt-chromium alloy, the conventional amalgam showing the highest values. The gold alloy and another nickel-chromium alloy exhibited low corrosion currents and they were noble with respect to cobalt-chromium.

  13. Alternativas para o tratamento de efluentes da indústria galvânica Alternatives for the galvanic wastewater treatment

    Directory of Open Access Journals (Sweden)

    Artur Pereira Neto

    2008-09-01

    Full Text Available Os métodos de precipitação química, cristalização e extração líquido-líquido foram aplicados visando propor alternativas para o tratamento de efluentes líquidos gerados pela indústria de galvanoplastia. Efluentes de diversas empresas do setor, localizadas no estado de Minas Gerais (Brasil, foram coletados e caracterizados. O efluente estudado, proveniente de empresa de galvanização de zinco a quente, continha cerca de 90 g/L de ferro total, 35 g/L de zinco e menores quantidades de Al, Ni e Cu, em meio ácido clorídrico (pH = 0,6. A separação seletiva entre ferro e zinco não se mostrou eficiente por precipitação, sendo a técnica adequada somente no tratamento do efluente, ao contrário da cristalização e extração líquido-líquido utilizando-se TBP como agente extratante. A integração destas técnicas ainda requer estudos mais detalhados visando à otimização de custos e das condições operacionais.Separation methods such as chemical precipitation, crystallization and liquid-liquid extraction have been investigated aiming to treat effluents generated by the galvanic industry. Effluent samples generated by several companies located in the state of Minas Gerais (Brazil were collected and chemically characterized. For this work, a typical zinc hot-dip galvanizing effluent containing about 90 g/L of total iron, 35 g/L of zinc and minor amounts of Al, Ni, Cu, in HCl medium (pH = 0.6 was treated. A selective separation between metals zinc and iron was not achieved by chemical precipitation, which was found adequate to threat water only. On contrary, zinc and iron was separated very efficiently by crystallization and liquid-liquid extraction using TBP as extractant agent. The integration of these methods to recover zinc and iron from effluent still requires more detailed studies.

  14. Pro Spring Batch

    CERN Document Server

    Minella, Michael T

    2011-01-01

    Since its release, Spring Framework has transformed virtually every aspect of Java development including web applications, security, aspect-oriented programming, persistence, and messaging. Spring Batch, one of its newer additions, now brings the same familiar Spring idioms to batch processing. Spring Batch addresses the needs of any batch process, from the complex calculations performed in the biggest financial institutions to simple data migrations that occur with many software development projects. Pro Spring Batch is intended to answer three questions: *What? What is batch processing? What

  15. Galvanic Cells: Anodes, Cathodes, Signs and Charges

    Science.gov (United States)

    Goodwin, Alan

    2011-01-01

    Electrochemistry is a difficult subject for students at school and beyond and even for their teachers. This article explores the difficult "truth" that, when a current flows from a galvanic cell, positive ions within the cell electrolyte move towards the electrode labelled positive. This seems to contravene the basic rule that like charges repel…

  16. Galvanic Cells: Anodes, Cathodes, Signs and Charges

    Science.gov (United States)

    Goodwin, Alan

    2011-01-01

    Electrochemistry is a difficult subject for students at school and beyond and even for their teachers. This article explores the difficult "truth" that, when a current flows from a galvanic cell, positive ions within the cell electrolyte move towards the electrode labelled positive. This seems to contravene the basic rule that like charges repel…

  17. Cr(VI) reduction in wastewater using a bimetallic galvanic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lugo-Lugo, Violeta [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Universidad Autonoma del Estado de Mexico, Facultad de Quimica. Paseo Colon interseccion Paseo Tollocan S/N. C.P. 50120, Toluca (Mexico); Barrera-Diaz, Carlos, E-mail: cbarrera@uaemex.mx [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Universidad Autonoma del Estado de Mexico, Facultad de Quimica. Paseo Colon interseccion Paseo Tollocan S/N. C.P. 50120, Toluca (Mexico); Bilyeu, Bryan [Xavier University of Louisiana, Department of Chemistry, 1 Drexel Drive, New Orleans, LA 70125 (United States); Balderas-Hernandez, Patricia [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Universidad Autonoma del Estado de Mexico, Facultad de Quimica. Paseo Colon interseccion Paseo Tollocan S/N. C.P. 50120, Toluca (Mexico); Urena-Nunez, Fernando [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandon, Delegacion Miguel Hidalgo, C.P. 11801, Mexico, D.F. (Mexico); Sanchez-Mendieta, Victor [Centro Conjunto de Investigacion en Quimica Sustentable UAEM-UNAM, Universidad Autonoma del Estado de Mexico, Facultad de Quimica. Paseo Colon interseccion Paseo Tollocan S/N. C.P. 50120, Toluca (Mexico)

    2010-04-15

    The electrochemical reduction of Cr(VI)-Cr(III) in wastewater by iron and copper-iron bimetallic plates was evaluated and optimized. Iron has been used as a reducing agent, but in this work a copper-iron galvanic system in the form of bimetallic plates is applied to reducing hexavalent chromium. The optimal pH (2) and ratio of copper to iron surface areas (3.5:1) were determined in batch studies, achieving a 100% reduction in about 25 min. The Cr(VI) reduction kinetics for the bimetallic system fit a first order mechanism with a correlation of 0.9935. Thermodynamic analysis shows that the Cr(VI) reduction is possible at any pH value. However, at pH values above 3.0 for iron and 5.5 for chromium insoluble species appear, indicating that the reaction will be hindered. Continuous column studies indicate that the bimetallic copper-iron galvanic system has a reduction capacity of 9.5890 mg Cr(VI) cm{sup -2} iron, whereas iron alone only has a capacity of 0.1269 mg Cr(VI) cm{sup -2}. The bimetallic copper-iron galvanic system is much more effective in reducing hexavalent chromium than iron alone. The exhausted plates were analyzed by SEM, EDS, and XRD to determine the mechanism and the surface effects, especially surface fouling.

  18. Oxygen analyzers: failure rates and life spans of galvanic cells.

    Science.gov (United States)

    Meyer, R M

    1990-07-01

    Competing technologies exist for measuring oxygen concentrations in breathing circuits. Over a 4-year period, two types of oxygen analyzers were studied prospectively in routine clinical use to determine the incidence and nature of malfunctions. Newer AC-powered galvanic analyzers (North American Dräger O2med) were compared with older, battery-powered polarographic analyzers (Ohmeda 201) by recording all failures and necessary repairs. The AC-powered galvanic analyzer had a significantly lower incidence of failures (0.12 +/- 0.04 failures per machine-month) than the battery-powered polarographic analyzer (4.0 +/- 0.3 failures per machine-month). Disposable capsules containing the active galvanic cells lasted 12 +/- 7 months. Although the galvanic analyzers tended to remain out of service longer, awaiting the arrival of costly parts, the polarographic analyzers were more expensive to keep operating when calculations included the cost of time spent on repairs. Stocking galvanic capsules would have decreased the amount of time the galvanic analyzers were out of service, while increasing costs. In conclusion, galvanic oxygen analyzers appear capable of delivering more reliable service at a lower overall cost. By keeping the galvanic capsules exposed to room air during periods of storage, it should be possible to prolong their life span, further decreasing the cost of using them. In addition, recognizing the aberrations in their performance that warn of the exhaustion of the galvanic cells should permit timely recording and minimize downtime.

  19. 热浸锌

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Composition. Testing, and Control of Hot Dip Galvanizing Flux;Corrosion behavior of steel ropes;Current process and equipment developments in the field of hot dip galvanizing; Development of a new hypereutectoid steel for high-strength wire; Effect of the substrate compositions on the growth of Fe-AI interracial layer formed during hot dip galvanizing;

  20. Spring batch essentials

    CERN Document Server

    Rao, P Raja Malleswara

    2015-01-01

    If you are a Java developer with basic knowledge of Spring and some experience in the development of enterprise applications, and want to learn about batch application development in detail, then this book is ideal for you. This book will be perfect as your next step towards building simple yet powerful batch applications on a Java-based platform.

  1. Characterization of Sludge from the Process of Steel Tubes Chemical Treatment for Hot Galvanizing

    Directory of Open Access Journals (Sweden)

    Sofilić, U.

    2009-10-01

    Full Text Available Inadequate industrial waste management in Croatia is reflected in the non-sanitary waste disposal, low recycling levels, negligible share of waste processing technologies, insufficient control of its flows, etc.Generated industrial wastes are most frequently disposed of at producers’ own, mostly illegal landfills. There are many such landfills on the Croatian territory, and the disposed types of waste often include those that can be hazardous and represent a considerable source of environmental pollution.Past waste management in all industrial branches can be characterized in this way, which at the same time may result in the harmful impact on human health and the environment. It also represents economic loss due to low utilisation of material and energy potential of some industrial wastes. The metallurgical industry collects its production waste separately. Only a part of the generated waste is returned to the production process and some waste is occasionally used by other industries as secondary raw materials, but the largest part of it ends at producers' own landfills on site. Hazardous wastes (dust containing heavy metals, waste oils etc. are mostly disposed of in a controlled and lawful manner. Past handling of metallurgical waste was unacceptable both from the environmental and economic point of view. Therefore a systematic resolving of this important issue was initiated at the beginning of this decade. Sisak Steelworks galvanized steel pipes in the hot-dip galvanizing procedure by immersing in molten zinc. Between 1970 and 2000 Sisak Steelworks produced approximately 900 000 tonnes of galvanized pipes this way and generated around 70 000 m3 of neutralisation sludge, which was subsequently disposed of in the landfill on site. The paper presents the results of examination of physical-chemical properties of neutralisation sludge generated as waste material in the process of neutralisation of waste sulphate acid bath used in Sisak

  2. Galvanic displacement of metals on semiconductor nanocrystals

    Science.gov (United States)

    Johnson, Melanie; Kelly, Joel A.; Henderson, Eric J.; Veinot, Jonathan G. C.

    2009-11-01

    We report the galvanic displacement (GD) of germanium from germanium nanocrystals (Ge-NCs) with silver. The Ge-NCs are synthesized by reductive thermal processing of germanium suboxide sol-gel prepolymers. Thermal processing yields size-controlled oxide-embedded Ge-NCs, which are liberated by dissolution of the germanium oxide matrix in water. Subsequent exposure of the freestanding Ge-NCs to aqueous solutions of AgNO3 leads to deposition of silver nanostructures by GD. The resulting metal structures were analyzed by XRD, XPS, TEM and EDX, confirming deposition of elemental silver in a variety of shapes and sizes.

  3. Galvanic displacement of metals on semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Melanie; Kelly, Joel A; Henderson, Eric J; Veinot, Jonathan G C, E-mail: jveinot@ualberta.ca [University of Alberta, Department of Chemistry, Edmonton, AB, T6G 2G2 (Canada)

    2009-11-15

    We report the galvanic displacement (GD) of germanium from germanium nanocrystals (Ge-NCs) with silver. The Ge-NCs are synthesized by reductive thermal processing of germanium suboxide sol-gel prepolymers. Thermal processing yields size-controlled oxide-embedded Ge-NCs, which are liberated by dissolution of the germanium oxide matrix in water. Subsequent exposure of the freestanding Ge-NCs to aqueous solutions of AgNO{sub 3} leads to deposition of silver nanostructures by GD. The resulting metal structures were analyzed by XRD, XPS, TEM and EDX, confirming deposition of elemental silver in a variety of shapes and sizes.

  4. 76 FR 19382 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-04-07

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission... Mexico of galvanized steel wire, provided for in subheading 7217.20.30 and 7217.20.45 of the...

  5. Tropical Weather Resistant Galvanized Steel Coated and Uncoated

    Directory of Open Access Journals (Sweden)

    Suárez-Corrales Xenia Isbel

    2014-01-01

    Full Text Available The corrosion behavior of coated and uncoated galvanized steel products is determined by exposing them to accelerated and natural climatic test. Accelerated tests were carried out in climatic chambers and natural atmospheric test in a marine-coastal station (Cojimar. The influence of tropical humid climate on these products is determined. Adhesion is an important property for a good performance, from the decorative point of view or as an additional protection. The evaluation indicates that 95% of the galvanized steel products show a good corrosion resistance; although 71% of coated galvanized products and 100% of painted galvanized products do not cover the requirements with respect to the mechanical and corrosion protection aspects. For a good efficiency and economic performance of metal mechanical industry, a correct surface treatment and coating application is required. A key point is to increase the quality by improving a better corrosion protective performance respecting uncoated galvanized steel.

  6. Structure and properties of composite ceramic coatings on H13 steel by hot dipping aluminum and plasma electrolytic oxidation%H13热作模具钢微弧氧化复合陶瓷层的组织和性能

    Institute of Scientific and Technical Information of China (English)

    赵建华; 赵国华; 李涛; 刘鑫; 李佳丽; 韩二静

    2012-01-01

    通过热浸镀铝/微弧氧化复合工艺对H13模具钢进行表面改性以提高模具表面质量。在热浸镀铝过程中,将H13钢基体浸入710℃纯铝液6 min,得到了以Fe2Al5为主中间合金层,使得镀层与基体紧密结合。经过微弧氧化处理后,镀铝试样表面铝层转化为氧化铝陶瓷,主要由α-Al2O3和γ-Al2O3相组成。用带有能谱分析装置(EDX)的扫描电镜(SEM)、X射线衍射(XRD)分析了膜层的形貌、成分和相组成。微弧氧化陶瓷层主要由Al、O、Si元素组成,其中O、Si主要来源于硅酸盐电解液。%Hot dipping pure aluminum on a H13 steel followed by plasma electrolytic oxidation(PEO) was performed to prepare composite ceramic coating on the H13 steel surface.H13 steel bars were first dipped in pure aluminum melts(710 ℃) for 6 min,and a Fe2Al5 intermetallic layer was obtained at the interface between the melt and the steel substrate.The intermetallic layer significantly improved the adhesion strength between Al layer and substrate.After PEO processing,uniform Al2O3 ceramic coatings were deposited on the surface of aluminized steel.The composition,phases and morphology of the aluminized layer and the ceramic coatings were characterized by SEM/EDX and XRD.The PEO layers mainly consist of α-Al2O3 and γ-Al2O3.The element O and Si in the ceramic layers came from the alkaline electrolytle.

  7. Galvanic cell for processing of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2017-02-07

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  8. Galvanic gold plating for fixed dental prosthesis.

    Science.gov (United States)

    Ozcelik, Tuncer Burak; Yilmaz, Burak

    2013-07-01

    Metal ceramic partial fixed dental prostheses have been commonly used for the replacement of missing teeth for many years. Because of an increase in the price of gold, base metal alloys have been the choice of alloy for the fabrication of metal ceramic restorations in many dental clinics. Some major disadvantages of base metals are their corrosion and the dark coloration they may cause at the crown margins. This article describes a galvanic gold-plating technique, which is used to minimize corrosion and improve the esthetics of metal ceramic restorations fabricated with Cr-Co base metal alloys. This technique involves the deposition of a 6 μm to 8 μm 24 K gold layer directly onto the Cr-Co cast prosthesis framework. The technique improves metal surface properties, making them more biocompatible and usable, however, requires additional equipment and experienced laboratory technicians. Clinical studies should be performed to corroborate the long term success of this technique.

  9. Rechargeable galvanic cell. Wiederaufladbare galvanische Batterie

    Energy Technology Data Exchange (ETDEWEB)

    Knoedler, R.; Mennicke, S.

    1982-11-11

    Rechargeable galvanic batteries using liquid sodium as negative electro-chemical material and liquid sulphur absorbed in graphite as the positive one as well as sodium-ion-conducting solid electrolytes which, in the battery housing, are designed as containers open to one side and filled with either sulphur or sodium and which have one collector each, are developed further by using the advantages of 'normal cells' and 'inverted cells' while reducing their disadvantages at the same time. This is obtained by designing the battery to consist in at least two parallelly arranged single cells connected in series via the housing and showing an inverted arrangement of sodium and sulphur relative to each other.

  10. Hybrid Batch Bayesian Optimization

    CERN Document Server

    Azimi, Javad; Fern, Xiaoli

    2012-01-01

    Bayesian Optimization aims at optimizing an unknown non-convex/concave function that is costly to evaluate. We are interested in application scenarios where concurrent function evaluations are possible. Under such a setting, BO could choose to either sequentially evaluate the function, one input at a time and wait for the output of the function before making the next selection, or evaluate the function at a batch of multiple inputs at once. These two different settings are commonly referred to as the sequential and batch settings of Bayesian Optimization. In general, the sequential setting leads to better optimization performance as each function evaluation is selected with more information, whereas the batch setting has an advantage in terms of the total experimental time (the number of iterations). In this work, our goal is to combine the strength of both settings. Specifically, we systematically analyze Bayesian optimization using Gaussian process as the posterior estimator and provide a hybrid algorithm t...

  11. Heuristics for batching and sequencing in batch processing machines

    Directory of Open Access Journals (Sweden)

    Chuda Basnet

    2016-12-01

    Full Text Available In this paper, we discuss the “batch processing” problem, where there are multiple jobs to be processed in flow shops. These jobs can however be formed into batches and the number of jobs in a batch is limited by the capacity of the processing machines to accommodate the jobs. The processing time required by a batch in a machine is determined by the greatest processing time of the jobs included in the batch. Thus, the batch processing problem is a mix of batching and sequencing – the jobs need to be grouped into distinct batches, the batches then need to be sequenced through the flow shop. We apply certain newly developed heuristics to the problem and present computational results. The contributions of this paper are deriving a lower bound, and the heuristics developed and tested in this paper.

  12. Iron serves as diffusion barrier in thermally regenerative galvanic cell

    Science.gov (United States)

    Crouthamel, C. E.

    1967-01-01

    Pure iron or iron-coated diaphragm provides a hydrogen diffusion electrode for a thermally regenerative galvanic cell. It allows the gas to diffuse through its interatomic spaces and resists the corrosive action of the cell environment.

  13. Technical report on galvanic cells with fused-salt electrolytes

    Science.gov (United States)

    Cairns, E. J.; Crouthamel, C. E.; Fischer, A. K.; Foster, M. S.; Hesson, J. C.; Johnson, C. E.; Shimotake, H.; Tevebaugh, A. D.

    1969-01-01

    Technical report is presented on sodium and lithium cells using fused salt electrolytes. It includes a discussion of the thermally regenerative galvanic cell and the secondary bimetallic cell for storage of electricity.

  14. 76 FR 21914 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-04-19

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject antidumping and countervailing duty investigations....

  15. Behavior of galvanized steel tube subjected to web crippling

    Institute of Scientific and Technical Information of China (English)

    黄淑琼; 陈誉; 王潮阳; 杜国锋

    2016-01-01

    The details of a research study of galvanized steel tube under web crippling were presented. A total of 48 galvanized steel square hollow sections with different boundary conditions, loading conditions, bearing lengths and web slenderness were tested. The experimental scheme, failure modes, load−displacement curves and strain intensity distribution curves were also presented. The investigation was focused on the effects of loading condition, bearing length and slenderness on web crippling ultimate capacity, initial compressive stiffness and ductility of galvanized steel tube. The results show that web crippling ultimate capacity increases linearly with the increase of the bearing lengthunder EOF and IOF loading condition. In the end-flange and ITF loading conditions, strain intensity of the centerline of web reaches the peak and decreases progressively from central web to flanges. Finite element models were developed to numerically simulate the tests in terms of failure modes and ultimate capacity. Web crippling strength of galvanized steel tube increases linearly with the increase of the ratio of the bearing length to web thickness and decrease of web slenderness. The effect of ratio of galvanized layer thickness to web thickness on web crippling strength is small. Based on the results of the parametric study, a number of calculation formulas proposed in this work can be successfully employed as a design rule for predicting web crippling ultimate capacity of galvanized steel tube under four loading and boundary conditions.

  16. 热浸锌

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    SY509-3-148 [篇名] Fatigue design of welded very thin-walled tube-to-plate joints using the classification method;SY509-3-149 [篇名] Fatigue test on Large-scale Welded Girder Specimens with Hot Dip Galvanizing - Fatigue Strength of Welded Joints by Hot Dip Galvanizing (Report 2) -……

  17. Dynamic Batch Bayesian Optimization

    CERN Document Server

    Azimi, Javad; Fern, Xiaoli

    2011-01-01

    Bayesian optimization (BO) algorithms try to optimize an unknown function that is expensive to evaluate using minimum number of evaluations/experiments. Most of the proposed algorithms in BO are sequential, where only one experiment is selected at each iteration. This method can be time inefficient when each experiment takes a long time and more than one experiment can be ran concurrently. On the other hand, requesting a fix-sized batch of experiments at each iteration causes performance inefficiency in BO compared to the sequential policies. In this paper, we present an algorithm that asks a batch of experiments at each time step t where the batch size p_t is dynamically determined in each step. Our algorithm is based on the observation that the sequence of experiments selected by the sequential policy can sometimes be almost independent from each other. Our algorithm identifies such scenarios and request those experiments at the same time without degrading the performance. We evaluate our proposed method us...

  18. Modelling of Batch Process Operations

    DEFF Research Database (Denmark)

    2011-01-01

    Here a batch cooling crystalliser is modelled and simulated as is a batch distillation system. In the batch crystalliser four operational modes of the crystalliser are considered, namely: initial cooling, nucleation, crystal growth and product removal. A model generation procedure is shown that s...

  19. Galvanic sludge metals recovery by pyrometallurgical and hydrometallurgical treatment.

    Science.gov (United States)

    Rossini, Gustavo; Bernardes, Andréa Moura

    2006-04-17

    This paper reports a study, on laboratory scale, of sulphating roasting to perform a treatment for a selective recovery of valuable metals from galvanic sludge. The target metals were copper, zinc and nickel and the sulphating agent used was pyrite, from coal wastes. The particularity of this treatment is the use of two hazardous wastes as raw material. They are generated in large quantities at coal extraction sites (coal wastes) and at plating shops (galvanic sludge). The wastes were characterized by X-ray fluorescence (XRF), particle size distribution and water contents. The chemical characterization showed sludges with high copper concentration, with more than 14% (dry base). In the roasting step, the galvanic sludge was mixed with pyritic waste and the parameters evaluated were galvanic sludge/pyrite ratio, roasting temperature and roasting time. After roasting, the product of reaction was leached with water in room temperature for 15 min. Considering that other studies have already demonstrated that the pyrometallurgical step determines the process efficiency, this paper only reports the influence of pyrometallurgical parameters. Hydrometallurgical processes will be better evaluated in further studies. The conditions that best reflect a compromise between the valuable metal recover and the economical viability of the process were achieved for 1:0.4 galvanic sludge/pyrite ratio, 90 min of roasting time and 550 degrees C of roasting temperature. These conditions lead to a recovery of 60% zinc, 43% nickel and 50% copper.

  20. The Galvanic Corrosion of Graphite Epoxy Composite Materials Coupled with Alloys

    Science.gov (United States)

    1975-12-01

    32 vi GAE/MC/75-8 Figure Page t 17 Circuit Diagram of Potentiostat ZRA Used to Measure Galvanic Current with the Galvanic Cell Represented...requirements for a galvanic cell can exist on the surface of any metal or alloy regardless of its noble nature; namely, a cathode, anode, metallic conductor... galvanic cell is short- circuited, and net oxidation and reduction processes take place at the electrode interfaces, the potentials of the anode and

  1. A microfluidic galvanic cell on a single layer of paper

    Science.gov (United States)

    Purohit, Krutarth H.; Emrani, Saina; Rodriguez, Sandra; Liaw, Shi-Shen; Pham, Linda; Galvan, Vicente; Domalaon, Kryls; Gomez, Frank A.; Haan, John L.

    2016-06-01

    Paper microfluidics is used to produce single layer galvanic and hybrid cells to produce energy that could power paper-based analytical sensors. When two aqueous streams are absorbed onto paper to establish co-laminar flow, the streams stay in contact with each other with limited mixing. The interface at which mixing occurs acts as a charge-transfer region, eliminating the need for a salt bridge. We designed a Cusbnd Zn galvanic cell that powers an LED when two are placed in series. We also used more powerful redox couples (formate and silver, formate and permanganate) to produce higher power density (18 and 3.1 mW mg-1 Pd). These power densities are greater than previously reported paper microfluidic fuel cells using formate or methanol. The single layer design is much more simplified than previous reports of multi-layer galvanic cells on paper.

  2. Hydrogen embrittlement and galvanic corrosion of titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Soh, Jeong Ryong; Jeong, Y. H.; Choi, B. K.; Baek, J. H.; Hwang, D. Y.; Choi, B. S.; Lee, D. J

    2000-06-01

    The material properties including the fracture behavior of titanium alloys used as a steam generator tube in SMART can be degraded de to the hydrogen embrittlement and the galvanic corrosion occurring as a result of other materials in contact with titanium alloys in a conducting corrosive environment. In this report the general concepts and trends of hydrogen embrittlement are qualitatively described to adequately understand and expect the fracture behavior from hydrogen within the bulk of materials and under hydrogen containing environments because hydrogen embrittlement may be very complicated process. And the characteristics of galvanic corrosion closely related to hydrogen embrittlement is qualitatively based on wimple electrochemical theory.

  3. Galvanic corrosion of nitinol under deaerated and aerated conditions.

    Science.gov (United States)

    Pound, Bruce G

    2016-10-01

    Various studies have examined the corrosion rate of nitinol generally under deaerated conditions. Likewise, galvanic corrosion studies have typically involved deaerated solutions. This work addressed the effect of galvanic coupling on the corrosion current of electropolished nitinol in phosphate buffered saline and 0.9% sodium chloride under dearated and aerated conditions for times up to 24 h. Tests were performed on nitinol alone and coupled with MP35N in both the mechanically polished and passivated conditions. Aeration and galvanic coupling were found to have relatively little effect, indicating that the corrosion current is controlled by the anodic reaction. The current can be attributed entirely to Ni(2+) dissolution, which appears to be governed by solid-state mass transport of Ni(2+) through the passive oxide film. Because corrosion of EP nitinol is controlled by the anodic reaction, contact between EP nitinol and MP35N or other biomedical Co-Cr alloys is unlikely to result in significant galvanic effects in vivo. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1322-1327, 2016. © 2015 Wiley Periodicals, Inc.

  4. Galvanic Cells and the Determination of Equilibrium Constants

    Science.gov (United States)

    Brosmer, Jonathan L.; Peters, Dennis G.

    2012-01-01

    Readily assembled mini-galvanic cells can be employed to compare their observed voltages with those predicted from the Nernst equation and to determine solubility products for silver halides and overall formation constants for metal-ammonia complexes. Results obtained by students in both an honors-level first-year course in general chemistry and…

  5. Galvanic interaction between galena and pyrite in an open system

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li; LI Heping; XU Liping

    2006-01-01

    Galvanic interactions between sulfide minerals have very important influences on hydrometallurgical processes, the supergene enrichment of sulfides and the formation of acid mine drainage. By changing the concentrations of Fe3 + , the pH values, status of the flowing of the solution and the solution salinity ( e. g. the concentrations of Na2 SO4 ) and monitoring the galvanic currents and potentials, studies were conducted in this work on the galvanic interaction between pyrite acting as the anode and galena acting as the cathode. The results indicated that the concentrations of Fe3 + , pH values and the flowing of the solution exhibit a great effect on the galvanic interaction of galena-pyrite couple, while the salinity of the solution has only a slight influence on the interaction. The experiments also revealed that in case cracks exist on the surface of pyrite electrode, the potential of pyrite will decrease so sharply as to be lower than that of galena under the same experimental condition. The experimental results were explained in terms of the Butler-Volume equation and the theory of mixed potential.

  6. Developing Gold Nanowires by Galvanic Replication of Ion Track Templates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Scientists at the CAS Institute of Modern Physics (IMP) in Lanzhou, capital of northwest China's Gansu Province, recently made an essential advance in production and investigation of single- and polycrystalline gold nanowires by galvanic replication of ion track templates. Their work was published by the Nanotechnology (Vol. 17, 1922-1926, 2006).

  7. An Easy-to-Assemble Three-Part Galvanic Cell

    Science.gov (United States)

    Eggen, Per-Odd; Skaugrud, Brit

    2015-01-01

    The galvanic cell presented in this article is made of only three parts, is easy to assemble, and can light a red light emitting diode (LED). The three cell components consist of a piece of paper with copper sulfate, a piece of paper with sodium sulfate, and a piece of magnesium ribbon. Within less than 1 h, students have time to discuss the…

  8. Galvanic Cells and the Determination of Equilibrium Constants

    Science.gov (United States)

    Brosmer, Jonathan L.; Peters, Dennis G.

    2012-01-01

    Readily assembled mini-galvanic cells can be employed to compare their observed voltages with those predicted from the Nernst equation and to determine solubility products for silver halides and overall formation constants for metal-ammonia complexes. Results obtained by students in both an honors-level first-year course in general chemistry and…

  9. Common Student Misconceptions in Electrochemistry: Galvanic, Electrolytic, and Concentration Cells.

    Science.gov (United States)

    Sanger, Michael J.; Greenbowe, Thomas J.

    1997-01-01

    Investigates student (N=16) misconceptions concerning electrochemistry related to galvanic, electrolytic, and concentration cells. Findings indicate that most students demonstrating misconceptions were still able to calculate cell potentials correctly. Discusses common misconceptions and possible sources of these. Contains 33 references.…

  10. Sensors based on galvanic cell generated electrochemiluminescence and its application.

    Science.gov (United States)

    Luo, Lirong; Zhang, Zhujun

    2006-10-27

    In this paper, a novel electrochemiluminescence (ECL) imaging sensor array was developed for determination of hydrogen peroxide (H2O2), which was based on Cu/Zn alloy galvanic cell generated ECL. In alkaline solution, Cu/Zn galvanic cell was formed because of corrosion effect, the galvanic cell could supply stable potential for ECL generation of luminol, and the weak ECL emission could be enhanced by H(2)O(2). The galvanic cell sensor array was designed by putting Cu/Zn alloy in 96-well microtiter plates separately. The relative ECL intensity was proportional with the concentration of hydrogen peroxide in the range of 1.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and the detection limit was 3.0 x 10(-7) mol l(-1) (3sigma), the relative standard deviation (R.S.D.) for 11 parallel measurements of 1.0 x 10(-5)mol l(-1) H2O2 was 4.0%.

  11. An Easy-to-Assemble Three-Part Galvanic Cell

    Science.gov (United States)

    Eggen, Per-Odd; Skaugrud, Brit

    2015-01-01

    The galvanic cell presented in this article is made of only three parts, is easy to assemble, and can light a red light emitting diode (LED). The three cell components consist of a piece of paper with copper sulfate, a piece of paper with sodium sulfate, and a piece of magnesium ribbon. Within less than 1 h, students have time to discuss the…

  12. Note: Galvanic isolated voltage source using a single photodiode.

    Science.gov (United States)

    Stoican, O S

    2010-04-01

    A galvanic isolated voltage source able to provide several volts by using a single photodiode is described. A pulse-modulated laser beam is sent to a photodiode. By using a step-up transformer the amplitude of the variable voltage generated by the photodiode is increased. Adding a rectifier cell the variable voltage is converted back into a dc voltage.

  13. Common Student Misconceptions in Electrochemistry: Galvanic, Electrolytic, and Concentration Cells.

    Science.gov (United States)

    Sanger, Michael J.; Greenbowe, Thomas J.

    1997-01-01

    Investigates student (N=16) misconceptions concerning electrochemistry related to galvanic, electrolytic, and concentration cells. Findings indicate that most students demonstrating misconceptions were still able to calculate cell potentials correctly. Discusses common misconceptions and possible sources of these. Contains 33 references.…

  14. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    Microgravity exposure results in an adaptive central reinterpretation of information from multiple sensory sources to produce a sensorimotor state appropriate for motor actions in this unique environment, but this new adaptive state is no longer appropriate for the 1-g gravitational environment on Earth. During these gravitational transitions, astronauts experience deficits in both perceptual and motor functions including impaired postural control, disruption in spatial orientation, impaired control of locomotion that include alterations in muscle activation variability, modified lower limb kinematics, alterations in head-trunk coordination as well as reduced dynamic visual acuity. Post-flight changes in postural and locomotor control might have adverse consequences if a rapid egress was required following a long-duration mission, where support personnel may not be available to aid crewmembers. The act of emergency egress includes, but is not limited to standing, walking, climbing a ladder, jumping down, monitoring displays, actuating discrete controls, operating auxiliary equipment, and communicating with Mission Control and recovery teams while maintaining spatial orientation, mobility and postural stability in order to escape safely. The average time to recover impaired postural control and functional mobility to preflight levels of performance has been shown to be approximately two weeks after long-duration spaceflight. The postflight alterations are due in part to central reinterpretation of vestibular information caused by exposure to microgravity. In this study we will use a commonly used technique of transcutaneous electrical stimulation applied across the vestibular end organs (galvanic vestibular stimulation, GVS) to disrupt vestibular function as a simulation of post-flight disturbances. The goal of this project is an engineering human-in-the-loop evaluation of a device that can degrade performance of functional tasks (e.g. to maintain upright balance

  15. From Galvanic to Anti-Galvanic Synthesis of Bimetallic Nanoparticles and Applications in Catalysis, Sensing, and Materials Science.

    Science.gov (United States)

    Liu, Xiang; Astruc, Didier

    2017-04-01

    The properties of two alloyed metals have been known since the Bronze Age to outperform those of a single metal. How alloying and mixing metals applies to the nanoworld is now attracting considerable attention. The galvanic process, which is more than two centuries old and involves the reduction of a noble-metal cation by a less noble metal, has not only been used in technological processes, but also in the design of nanomaterials for the synthesis of bimetallic transition-metal nanoparticles. The background and nanoscience applications of the galvanic reactions (GRs) are reviewed here, in particular with emphasis on recent progress in bimetallic catalysis. Very recently, new reactions have been discovered with nanomaterials that contradict the galvanic principle, and these reactions, called anti-galvanic reactions (AGRs), are now attracting much interest for their mechanistic, synthetic, catalytic, and sensor aspects. The second part of the review deals with these AGRs and compares GRs and AGRs, including the intriguing AGRs mechanism and the first applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Surface cellular salient defects of galvanized steel sheets%镀锌板表面胞状凸起缺陷

    Institute of Scientific and Technical Information of China (English)

    陈连生; 胡宝佳; 宋进英; 田亚强; 郑小平; 邸光明

    2016-01-01

    Scanning electron microscopy along with energy dispersive spectroscopy and sample-electrolysing method was employed to investigate the causes for the formation of cellular salient defects on the surface of galvanized steel sheets. Results show that the skin defect of cold rolled steel sheet is the direct cause of the surface cellular salient defects of galvanized sheets. The strip of silicate inclusions larger than 300μm located at the subsurface area of the cold rolled steel sheet,and massive iron oxide lied among silicate inclusions. Mechanical grinding was conducted to remove the subsurface area of the pickling plate with the same defect batch,and the subsequent cold rolling test showed that the main reason of the surface defects of the galvanized sheet was not caused by massive iron oxide inclusions. The inclu-sion content in the casting billet of galvanized steel sheets with defects was 100.32 mg/10 kg which was composed of in-clusions larger than 140μm,while the normal value was 20.98 mg/10 kg for the casting billet of galvanized steel sheets without defects. The results proved that the fundamental cause of the surface cellular salient defects of galvanized steel sheets was the large silicate inclusions.%采用SEM、EDS和大样电解法研究了某种镀锌板表面胞状凸起缺陷的形成原因。结果表明:冷轧板表面起皮缺陷是造成镀锌板表面胞状凸起缺陷的直接原因。冷轧原料板近表层分布着尺寸大于300μm的长条状硅酸盐夹杂带,且夹杂带中分布着块状氧化铁夹杂。与缺陷镀锌板同批次酸洗板机械研磨去掉近表层,随后冷轧试验表明,块状氧化铁夹杂不是造成镀锌板表面胞状凸起缺陷的主要原因。缺陷镀锌板铸坯中夹杂物含量为100.32 mg/10 kg,夹杂物主要由尺寸大于140μm大型夹杂物组成,而正常镀锌板铸坯中夹杂物含量为20.98 mg/10 kg,证实钢中大型硅酸盐类夹杂是导致镀锌板表面凸起缺陷的根本原因。

  17. Galvanic apparent internal impedance: an intrinsic tissue property.

    Science.gov (United States)

    Golberg, Alex; Rabinowitch, Haim D; Rubinsky, Boris

    2009-11-01

    Using basic galvanic cell principles, the ability of tissues to generate electrical current through electrolysis was characterized. Studying Zn/Cu electrolysis in animal organs revealed a fundamental and measurable tissue-specific property - the galvanic apparent internal impedance (GAII), that is most likely related to the salt bridge function of tissues delineated by electrodes. Further to the fundamental knowledge acquired, GAII enables a new diagnostic method to distinguish between tissue types and to determine their health status without a need for expensive calibration, as often required when external power source is used. We demonstrated the GAII sensitivity in detecting tissue ablation with microwave heating or irreversible electroporation. The results open the way for a novel, inexpensive self-powered tissue diagnostic system for a wide range of applications such as minimally invasive tissue health status, ischemia, hydration, real time intra-operative control of minimally invasive surgery, medical imaging, virtual biopsy and many others.

  18. Galvanic cell without liquid junction for potentiometric determination of copper.

    Science.gov (United States)

    Migdalski, Jan; Błaz, Teresa; Zrałka, Barbara; Lewenstam, Andrzej

    2007-07-01

    This paper describes potentiometric measurements in an integrated galvanic cell with both indicator and reference electrodes. Both electrodes are conducting polymer-based. The copper-sensitive indicator electrode is made by using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with 2-(o-arsenophenylazo)-1,8-dihydroxynaphthalene-3,6-disulphonic sodium salt (Arsenazo-I) as the electroactive substance in the film, while the reference electrode is based on PEDOT doped by 2-morpholineoethanesulfonic acid (MES). It is shown that the galvanic cell can be used for determination of copper both in non-aqueous media (where all PVC-based membranes failed) and in the presence of chloride ions, which disturb the signal of conventional copper ion-selective electrodes with solid-state membranes. It is further shown that the titration of copper ions can be successfully monitored using the described electrochemical cell.

  19. Resistance Spot Weldability of Galvanize Coated and Uncoated TRIP Steels

    Directory of Open Access Journals (Sweden)

    Hayriye Ertek Emre

    2016-11-01

    Full Text Available In this study, the resistance spot weldabilty of zinc galvanize-coated and uncoated TRIP800 steels was investigated in detail. Depending on the welding parameters such as welding current and welding time, the effects of zinc coating on the weld nugget geometry, the tensile shear strength, the failure modes, the hardness, and the microstructure of the resistance spot-welded sample were studied, and the results are compared with that of uncoated weldment. The coating on the surface of the TRIP steel causes a decrease in the weld nugget size and tensile shear strength of the weldment, and it changes to failure mode of the test sample from pullout to interfacial or partial interfacial fracture. As compared with the uncoated sample, the galvanized TRIP800 steel weldment has required a larger critical nugget size for achieving the desired pullout fracture mode and acceptable tensile shear strength.

  20. Effect of natural marine biofilms on galvanic corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, S.C.; LaFontaine, J.P. [Univ. of Delaware, Lewes, DE (United States)

    1998-11-01

    Galvanic corrosion of copper (UNS C11000), 1018 carbon steel (CS, UNS G10180), aluminum alloy 3003 (UNS A93003), and zinc (UNS Z32121) coupled to cathodes of UNS N08367 was tested with and without natural marine biofilms on the cathode surface. Weight losses were significantly higher, and corrosion currents were up to 2 decades higher with a biofilm on the cathode surface for anodes of copper, steel, and aluminum. There was no difference for zinc. Results showed an increase in consumption of the anodic material should be expected in any case where biofilms on the cathodic member of a galvanic couple result in a systematic and significant increase in reduction current at the mixed potential of the couple. Cathodic reduction currents (versus control with no biofilm) were increased at all potentials down to {approximately}{minus}900 mV{sub SCE}, resulting in an elevated current capacity capable of increasing the weight loss of anodic materials over a sustained period of at least 2 months. Biofilms, however, did not increase consumption of zinc anodes. Potentiodynamic polarization curves taken from the corroded samples were used successfully to predict the effect of biofilms on galvanic corrosion rates for the materials tested. Weight-loss values calculated by Faraday`s law using corrosion currents from the polarization curves agreed well with actual measured values for anodes of steel, aluminum, and zinc, although there were some discrepancies for copper.

  1. A Galvanic Coupling Method for Assessing Hydration Rates

    Directory of Open Access Journals (Sweden)

    Clement Ogugua Asogwa

    2016-07-01

    Full Text Available Recent advances in biomedical sensors, data acquisition techniques, microelectronics and wireless communication systems opened up the use of wearable technology for ehealth monitoring. We introduce a galvanic coupled intrabody communication for monitoring human body hydration. Studies in hydration provide the information necessary for understanding the desired fluid levels for optimal performance of the body’s physiological and metabolic processes during exercise and activities of daily living. Current measurement techniques are mostly suitable for laboratory purposes due to their complexity and technical requirements. Less technical methods such as urine color observation and skin turgor testing are subjective and cannot be integrated into a wearable device. Bioelectrical impedance methods are popular but mostly used for estimating total body water with limited accuracy and sensitive to 800 mL–1000 mL change in body fluid levels. We introduce a non-intrusive and simple method of tracking hydration rates that can detect up to 1.30 dB reduction in attenuation when as little as 100 mL of water is consumed. Our results show that galvanic coupled intrabody signal propagation can provide qualitative hydration and dehydration rates in line with changes in an individual’s urine specific gravity and body mass. The real-time changes in galvanic coupled intrabody signal attenuation can be integrated into wearable electronic devices to evaluate body fluid levels on a particular area of interest and can aid diagnosis and treatment of fluid disorders such as lymphoedema.

  2. Gold recovery by galvanic stripping of an anionic organic extractant

    Directory of Open Access Journals (Sweden)

    Lacerda D.F.C.

    2001-01-01

    Full Text Available The galvanic stripping technique for metal recovery uses commercial organic extractants containing a metal to be recovered. The organic phase is placed in contact with a solid metal reducer that allows electrochemical reactions to occur. One product of these reactions is a metal layer deposited on the surface of the reducer consisting of reduced species desorbed from the organic phase. Another product is metal ions from the reducer adsorbed onto the organic phase. This work presents results for gold recovery by galvanic stripping of strong-base anionic extractants of a quaternary amine salt, ALIQUAT336®, in xylene using solid zinc as the metal reducer. The parameters studied were contact time for the organic phase containing gold and the samples of the reducing zinc metal, temperature of the system, gold concentration in the organic phase and type of stirring used in the galvanic stripping system. Experiments showed results higher than 28% of gold recovery and an adherent film of gold on the zinc surface. The Arrhenius plot for gold recovery from the organic extractant suggests a change in the rate- controlling step from mixed control to diffusion control with increasing temperature in the range of 20 to 50ºC.

  3. Galvanic manufacturing in the cities of Russia: potential source of ambient nanoparticles.

    Directory of Open Access Journals (Sweden)

    Kirill S Golokhvast

    Full Text Available Galvanic manufacturing is widely employed and can be found in nearly every average city in Russia. The release and accumulation of different metals (Me, depending on the technology used can be found in the vicinities of galvanic plants. Under the environmental protection act in Russia, the regulations for galvanic manufacturing do not include the regulations and safety standards for ambient ultrafine and nanosized particulate matter (PM. To assess whether Me nanoparticles (NP are among environmental pollutants caused by galvanic manufacturing, the level of Me NP were tested in urban snow samples collected around galvanic enterprises in two cities. Employing transmission electronic microscopy, energy-dispersive X-ray spectroscopy, and a laser diffraction particle size analyzer, we found that the size distribution of tested Me NP was within 10-120 nm range. This is the first study to report that Me NP of Fe, Cr, Pb, Al, Ni, Cu, and Zn were detected around galvanic shop settings.

  4. Data-driven batch schuduling

    Energy Technology Data Exchange (ETDEWEB)

    Bent, John [Los Alamos National Laboratory; Denehy, Tim [GOOGLE; Arpaci - Dusseau, Remzi [UNIV OF WISCONSIN; Livny, Miron [UNIV OF WISCONSIN; Arpaci - Dusseau, Andrea C [NON LANL

    2009-01-01

    In this paper, we develop data-driven strategies for batch computing schedulers. Current CPU-centric batch schedulers ignore the data needs within workloads and execute them by linking them transparently and directly to their needed data. When scheduled on remote computational resources, this elegant solution of direct data access can incur an order of magnitude performance penalty for data-intensive workloads. Adding data-awareness to batch schedulers allows a careful coordination of data and CPU allocation thereby reducing the cost of remote execution. We offer here new techniques by which batch schedulers can become data-driven. Such systems can use our analytical predictive models to select one of the four data-driven scheduling policies that we have created. Through simulation, we demonstrate the accuracy of our predictive models and show how they can reduce time to completion for some workloads by as much as 80%.

  5. On the distribution of batch shelf lives.

    Science.gov (United States)

    Quinlan, Michelle; Stroup, Walter; Christopher, David; Schwenke, James

    2013-01-01

    Implicit in ICH Q1E (International Conference on Harmonization [ICH], 2003b ) are definitions of batch shelf life (the time the batch mean crosses the acceptance limit) and product shelf life (the minimum batch shelf life). The distribution of batch means over time projects to a distribution of batch shelf lives on the x-axis. Assuming multivariate normality, shelf life is the ratio of correlated Gaussian variables. Using Hinkley ( 1969 ), we describe the relationship between quantiles of the distributions of batch shelf lives and batch means. Exploiting this relationship, a linear mixed model is used to estimate a target quantile of batch shelf lives to address the ICH objective.

  6. Practical Impacts of Galvanic Corrosion in Water Service Lines and Premise Plumbing

    OpenAIRE

    StClair, Justin Monroe

    2013-01-01

    There is emerging concern about the potential for elevated lead in water after water utilities conduct EPA mandated (or voluntary) partial replacements of existing lead service lines. Connections between dissimilar metals results in the accelerated corrosion of the less noble metal via galvanic attack, increasing metal concentrations in water and posing potential public health risks. Many practical problems associated with stopping galvanic attack between copper:galvanized iron and copper:lea...

  7. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 1: formative years, naturphilosophie, and galvanism.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    During the 1790s, Alexander von Humboldt (1769-1859), who showed an early interest in many facets of natural philosophy and natural history, delved into the controversial subject of galvanism and animal electricity, hoping to shed light on the basic nature of the nerve force. He was motivated by his broad worldview, the experiments of Luigi Galvani, who favored animal electricity in more than a few specialized fishes, and the thinking of Alessandro Volta, who accepted specialized fish electricity but was not willing to generalize to other animals, thinking Galvani's frog experiments flawed by his use of metals. Differing from many German Naturphilosophen, who shunned "violent" experiments, the newest instruments, and detailed measurement, Humboldt conducted thousands of galvanic experiments on animals and animal parts, as well as many on his own body, some of which caused him great pain. He interpreted his results as supporting some but not all of the claims made by both Galvani and Volta. Notably, because of certain negative findings and phenomenological differences, he remained skeptical about the intrinsic animal force being qualitatively identical to true electricity. Hence, he referred to a "galvanic force," not animal electricity, in his letters and publications, a theoretical position he would abandon with Volta's help early in the new century.

  8. 热浸锌

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    [篇名 ] A new dimension in discontinuous galvanizing, [篇名 ] A novel application of electrorefining in a membrane cell to reclaim zinc from the bottom dross of hot dip galvanization, [ 篇名 ] About the effect of melted zinc mass additives on the formation of layers during hot galvanizing, [篇名 ] Addition of an acrylic roll coatcr to the No.4 hot dip galvanizing line, [篇名 ] Case histories: Galvanized Steel in marine structures, [篇名] Comparison of the properties of galvanized welded Joints produced by diffcrent methods, [篇名 ] Complete edge testing of rolled material with improved inspection technique.

  9. BatchJobs and BatchExperiments: Abstraction Mechanisms for Using R in Batch Environments

    Directory of Open Access Journals (Sweden)

    Bernd Bischl

    2015-03-01

    Full Text Available Empirical analysis of statistical algorithms often demands time-consuming experiments. We present two R packages which greatly simplify working in batch computing environments. The package BatchJobs implements the basic objects and procedures to control any batch cluster from within R. It is structured around cluster versions of the well-known higher order functions Map, Reduce and Filter from functional programming. Computations are performed asynchronously and all job states are persistently stored in a database, which can be queried at any point in time. The second package, BatchExperiments, is tailored for the still very general scenario of analyzing arbitrary algorithms on problem instances. It extends package BatchJobs by letting the user define an array of jobs of the kind apply algorithm A to problem instance P and store results. It is possible to associate statistical designs with parameters of problems and algorithms and therefore to systematically study their influence on the results. The packages main features are: (a Convenient usage: All relevant batch system operations are either handled internally or mapped to simple R functions. (b Portability: Both packages use a clear and well-defined interface to the batch system which makes them applicable in most high-performance computing environments. (c Reproducibility: Every computational part has an associated seed to ensure reproducibility even when the underlying batch system changes. (d Abstraction and good software design: The code layers for algorithms, experiment definitions and execution are cleanly separated and enable the writing of readable and maintainable code.

  10. BatchJS: Implementing Batches in JavaScript

    NARCIS (Netherlands)

    Kasemier, D.

    2014-01-01

    None of our popular programming languages know how to handle distribution well. Yet our programs interact more and more with each other and our data resorts in databases and web services. Batches are a new addition to languages that can finally bring native support for distribution to our favourite

  11. Galvanic Vestibular Stimulation in Hemi-Spatial Neglect

    Directory of Open Access Journals (Sweden)

    David eWilkinson

    2014-01-01

    Full Text Available Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. However, it remains unclear whether this reduction persists after stimulation is stopped. To estimate longevity of effect, we therefore conducted a double-blind, randomized, dose-response trial involving a group of stroke patients suffering from left-sided neglect (n=52, mean age=66 years. To determine whether repeated sessions of galvanic vestibular stimulation more effectively induce lasting relief than a single session, participants received 1, 5, or 10 sessions, each lasting 25mins, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude=1mA. Ninety five percent confidence intervals indicated that all three treatment arms showed a statistically significant improvement between the pre-stimulation baseline and the final day of stimulation on the primary outcome measure, the conventional tests of the Behavioural Inattention Test. More remarkably, this change (mean change=28%, SD=18 was still evident 1month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index score, a measure of functional capacity, in the absence of any adverse events or instances of participant non-compliance. Together these data suggest that galvanic vestibular stimulation, a simple, cheap technique suitable for home-based administration, may produce lasting reductions in neglect that are clinically important. Further protocol optimization is now needed ahead of a larger effectiveness study.

  12. Analysis of Adiabatic Batch Reactor

    Directory of Open Access Journals (Sweden)

    Erald Gjonaj

    2016-05-01

    Full Text Available A mixture of acetic anhydride is reacted with excess water in an adiabatic batch reactor to form an exothermic reaction. The concentration of acetic anhydride and the temperature inside the adiabatic batch reactor are calculated with an initial temperature of 20°C, an initial temperature of 30°C, and with a cooling jacket maintaining the temperature at a constant of 20°C. The graphs of the three different scenarios show that the highest temperatures will cause the reaction to occur faster.

  13. Development of a highly sensitive galvanic cell oxygen sensor.

    Science.gov (United States)

    Ogino, H; Asakura, K

    1995-02-01

    A highly sensitive galvanic cell oxygen sensor was successfully developed for determining parts per billion of oxygen in high purity gases such as nitrogen, argon, etc. The response of this improved sensor was proportional in the range of oxygen concentrations from 10.0 ppm to the detection limit. The response speed in this study was improved to within 90 sec for a 90% response. The detection limit was tentatively found to be less than 0.4 ppb corresponding to S N = 2 .

  14. Effect of pellicle on galvanic corrosion of amalgam.

    Science.gov (United States)

    Holland, R I

    1984-02-01

    Galvanic corrosion of amalgam, induced by contact with a type IV dental casting gold alloy, was determined under simulated oral conditions in an electrochemical cell. The effect of a pellicle layer formed by 1 h exposure to saliva in the oral cavity was determined. Pellicle on the amalgam had no effect on the maximum corrosion rate or the 2 h corrosion charge, whereas pellicle on the gold alloy substantially reduced both these parameters of the conventional low-copper amalgam; the corrosion of the high-copper amalgam was less and was not influenced by pellicle formation.

  15. Finishes for Metals. Paintability of Galvanized Steel, Corrosion Resistance of Metallized Coatings.

    Science.gov (United States)

    Building Research Inst., Inc., Washington, DC.

    Two papers are presented. The first, "Report of the AISI Research Project on the Paintability of Galvanized Steel," was a project aimed at determining optimum procedures for painting bright-spangled galvanized sheet steel products using three classes of trade sales paints--metallic zinc-dust, portland cement-in-oil, and water base emulsion paints.…

  16. Galvanic corrosion behavior of die cast AZ91D magnesium alloy in chloride solution

    Institute of Scientific and Technical Information of China (English)

    Zhensong Tong; Wei Zhang; Jiuqing Li; Jin Gao; Jiquan He; Ji Zhou

    2004-01-01

    The galvanic corrosion behavior of die cast AZ91D magnesium alloy coupled with H62 brass, 316L stainless steel, A3steel and LY12 aluminum alloy of different areas in 3.5% NaC1 solution was studied. The free corrosion potentials, galvanic potentials and currents of these galvanic couples were measured. The galvanic effects were determined by the mass loss and regression method using three points. The results show that: (1) In these four kinds of couples AZ91D acts as the anode, whose galvanic corrosion behavior is mainly controlled by the cathodic polarization; (2) The free corrosion potentials of these four kinds of couples change a liffle with time and cathodic/anodic area ratio (CAAR); (3) The galvanic potential of AZ91D/LY12 moves positively with the increase of time and CAAR; (4) The galvanic currents increase with CAAR, but there is difference in the current change between different couples; (5) The anodic dissolution rate of the magnesium alloy increases by 2-3 orders after being coupled with these four kinds of metals and the galvanic effects of these couples have such a relation as γH62>γ316LS.S>γLY12 >γA3.

  17. Blistering of Graphite/Polymer Composites Galvanically Coupled with Metals in Sea Water

    Science.gov (United States)

    1991-01-01

    the formation of a galvanic cell . The steel C-clamps severely corroded and the composite blistered. Subsequently, research was instigated to determine...and quickly closes a galvanic cell . These blisters, as a result, seem to break open as soon as 11 (6a 6b Fiue a b Po eseIr~s’O avnc bitr Iabnga~/iy

  18. 7 CFR 1755.370 - RUS specification for seven wire galvanized steel strand.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false RUS specification for seven wire galvanized steel... steel strand. (a) RUS incorporates by reference ASTM A475-78, Standard Specification for Zinc-Coated Steel Wire Strand, issued May 1978. All seven wire galvanized steel strand purchased after April 1,...

  19. 76 FR 72721 - Galvanized Steel Wire From China and Mexico; Scheduling of the Final Phase of Countervailing Duty...

    Science.gov (United States)

    2011-11-25

    ... COMMISSION Galvanized Steel Wire From China and Mexico; Scheduling of the Final Phase of Countervailing Duty... Mexico of galvanized steel wire, provided for in subheading 7217.20 of the Harmonized Tariff Schedule of... the subject merchandise as galvanized steel wire which is a cold- drawn carbon quality steel...

  20. Galvanic coupling and its effect on origin potential flotation system of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    顾帼华; 戴晶平; 王晖; 邱冠周

    2004-01-01

    The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided into three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples,several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena (or sphalerite) and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe(OH)3 formed covers on the cathodic mineral surface, affecting its floatability.

  1. Corrosive microenvironments at lead solder surfaces arising from galvanic corrosion with copper pipe.

    Science.gov (United States)

    Nguyen, Caroline K; Stone, Kendall R; Dudi, Abhijeet; Edwards, Marc A

    2010-09-15

    As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and the copper. If the resulting galvanic current exceeds about 2 μA/cm(2), a highly corrosive microenvironment can form at the solder surface, with pH galvanic currents, preventing passivation of the solder surface, and contributing to lead contamination of potable water supplies. The total mass of lead corroded was consistent with predictions based on the galvanic current, and lead leaching to water was correlated with galvanic current. If the concentration of sulfate in the water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced, and solder surfaces were readily passivated.

  2. Physicochemical Characteristics of Transferon™ Batches

    Directory of Open Access Journals (Sweden)

    Emilio Medina-Rivero

    2016-01-01

    Full Text Available Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

  3. Physicochemical Characteristics of Transferon™ Batches

    Science.gov (United States)

    Pérez-Sánchez, Gilberto; Favari, Liliana; Estrada-Parra, Sergio

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes. PMID:27525277

  4. Physicochemical Characteristics of Transferon™ Batches.

    Science.gov (United States)

    Medina-Rivero, Emilio; Vallejo-Castillo, Luis; Vázquez-Leyva, Said; Pérez-Sánchez, Gilberto; Favari, Liliana; Velasco-Velázquez, Marco; Estrada-Parra, Sergio; Pavón, Lenin; Pérez-Tapia, Sonia Mayra

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

  5. Keeping Quality of Strawberry Batches

    NARCIS (Netherlands)

    Schouten, R.E.; Kooten, van O.

    2001-01-01

    Post-harvest life of strawberries is largely limited by Botrytis cinerea infection. It is assumed that there are two factors influencing the batch keeping quality: the botrytis pressure and the resistance of the strawberry against infection. The latter factor will be discussed here. A model is

  6. Batching System for Superior Service

    Science.gov (United States)

    2001-01-01

    Veridian's Portable Batch System (PBS) was the recipient of the 1997 NASA Space Act Award for outstanding software. A batch system is a set of processes for managing queues and jobs. Without a batch system, it is difficult to manage the workload of a computer system. By bundling the enterprise's computing resources, the PBS technology offers users a single coherent interface, resulting in efficient management of the batch services. Users choose which information to package into "containers" for system-wide use. PBS also provides detailed system usage data, a procedure not easily executed without this software. PBS operates on networked, multi-platform UNIX environments. Veridian's new version, PBS Pro,TM has additional features and enhancements, including support for additional operating systems. Veridian distributes the original version of PBS as Open Source software via the PBS website. Customers can register and download the software at no cost. PBS Pro is also available via the web and offers additional features such as increased stability, reliability, and fault tolerance.A company using PBS can expect a significant increase in the effective management of its computing resources. Tangible benefits include increased utilization of costly resources and enhanced understanding of computational requirements and user needs.

  7. NDA BATCH 2002-02

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Livermore National Laboratory

    2009-12-09

    QC sample results (daily background checks, 20-gram and 100-gram SGS drum checks) were within acceptable criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on 5 drums with IDs LL85101099TRU, LL85801147TRU, LL85801109TRU, LL85300999TRU and LL85500979TRU. All replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. Note that the batch covered 5 weeks of SGS measurements from 23-Jan-2002 through 22-Feb-2002. Data packet for SGS Batch 2002-02 generated using gamma spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with established control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable. An Expert Review was performed on the data packet between 28-Feb-02 and 09-Jul-02 to check for potential U-235, Np-237 and Am-241 interferences and address drum cases where specific scan segments showed Se gamma ray transmissions for the 136-keV gamma to be below 0.1 %. Two drums in the batch showed Pu-238 at a relative mass ratio more than 2% of all the Pu isotopes.

  8. Temperature Controlled Laser Joining of Aluminum to Galvanized Steel

    Science.gov (United States)

    Weller, Daniel; Simon, Jörg; Stritt, Peter; Weber, Rudolf; Graf, Thomas; Bezençon, Cyrille; Bassi, Corrado

    Reliable joining of 6000 series aluminum alloy to galvanized steel is a challenge for current manufacturing technologies. To control and limit the formation of brittle intermetallic phases, mixing of both metals in liquid state has to be avoided. It has been shown that laser weld-brazing is a possible process. Thereby the aluminum and zinc layer of the galvanized steel are molten and the steel remains solid during the process. In addition, to avoid zinc degassing, the aluminum melt bath temperature has to be below zinc boiling temperature of 907°C. To meet these requirements a temperature controlled laser process was developed, allowing to join the two materials without flux and filler material. The thickness of the intermetallic layer shows a dependency on the set temperature used to control the process. At optimum set temperature the thickness of intermetallic phases can be limited to about 5 μm. Tensile strengths of the joints of up to 75% of the aluminum base material were achieved.

  9. Vertical Soil Profiling Using a Galvanic Contact Resistivity Scanning Approach

    Directory of Open Access Journals (Sweden)

    Luan Pan

    2014-07-01

    Full Text Available Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument.

  10. Bending moment of galvanized iron glass fiber sandwich panel

    Directory of Open Access Journals (Sweden)

    Gurustal Somnath Swamy

    2016-05-01

    Full Text Available The main objective of this project is to prepare a laminated with Galvanized iron thickness fractions, fiber volume fractions and orientation in the layers of GF were fabricated by hand lay-up method and evaluated for their bending moment properties of the sandwich panel using universal testing machine. This paper theoretically calculates the bending behavior of sandwich panel. The recent need to develop a new range of materials has resulted in the development of high performance lightweight composites with excellent properties. Metal– composite systems consist of alternating layers of metal and fiber-reinforced polymer composites which are bonded by an adhesive. Sandwich beams were tested under Air Bending. Stress-strain and stress-displacement were recorded by using AIMIL UTM. The beam face sheets exhibited a softening non-linearity on the bending side. Experimental results were in good agreement with predictions from simple models. On an overall basis, the sandwich panel exhibited better bending moment performance than the monolithic galvanized iron

  11. Galvanizing industry: evaluation of exposure levels using biomonitors

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Maria Angela de B.C.; Sabino, Claudia de V.S.; Amaral, Angela Maria [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Mattos, Silvania V. de M. [FUNED, Belo Horizonte, MG (Brazil). Div. de Bromatologia e Toxicologia; S. Filho, Serafim [Secretaria Municipal de Saude de Belo Horizonte, MG (Brazil). Coordenacao de Saude do Trabalhador; Maia, Elene Cristina P. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    1999-11-01

    In Brazil, statistical surveys concerning occupational diseases refer to accidents and damages. The surveys do not refer to the occupational diseases developed through long exposures to hazardous work conditions, involving physical risk and toxic chemical substances. The Program of Medical Control of Occupational Health determines the Maximum Biological Levels Allowed and the Values of Normality References. But concerning metal and toxic inorganic, values of only few elements are established. In Belo Horizonte and surroundings areas, which is an important industrial centre in the country, there are different industries distributed over various areas. There are about 80 galvanizing industries which are responsible for the majority of the metal contamination hospitalities. A preliminary sampling was performed in order to conduct a survey of the exposures to elements related to occupational diseases in galvanizing industry. The preliminary results for toxic and non-toxic elements obtained using hair and fingernails as biomonitors are shown. The K{sub 0} parametric neutron activation analysis method was applied and the elements determined were: Ag, Al, Au, Cl, Co, Cr, Cu, Fe, I, Mn, Na, Ti, V, Ta, and Zn. (author) 8 refs., 3 figs., 2 tabs.; e-mail: menezes at urano.cdtn.br

  12. Vertical soil profiling using a galvanic contact resistivity scanning approach.

    Science.gov (United States)

    Pan, Luan; Adamchuk, Viacheslav I; Prasher, Shiv; Gebbers, Robin; Taylor, Richard S; Dabas, Michel

    2014-07-23

    Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep) soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument.

  13. Electrochemical properties of suprastructures galvanically coupled to a titanium implant.

    Science.gov (United States)

    Oh, Keun-Taek; Kim, Kyoung-Nam

    2004-08-15

    In recent years, dental implants have been widely used for the aesthetic and functional restoration of edentulous patients. Dental implants and restorative alloys are required with high corrosion resistance. Suprastructures and implants of different compositions in electrical contact may develop galvanic or coupled corrosion problems. In addition to galvanic corrosion, crevice and pitting corrosion may occur in the marginal gap between dental implant assemblies. In this study, gold, silver-palladium, cobalt-chromium, and nickel-chromium suprastructures were used to investigate their galvanic and crevice corrosion characteristics in combination with titanium (Ti) implants. Potentiodynamic and potentiostatic testing were performed in artificial saliva at 37 degrees C. Potentiodynamic testing was carried out at the potential scan rate of 1 mV/s in the range of -600-1600 mV (SCE). Potentiostatic testing was performed with an open-circuit potential and current densities at -250, 0, and 250 mV (SCE) in artificial saliva. After electrochemical testing, surface morphologies and cross-sections were examined using micrographs of the samples. Potentiodynamic test results indicated that suprastructure/Ti implant couples produced passive current densities in the range of 0.5-12 microA/cm(2); Ti abutment/Ti implant and gold/Ti implant couples exhibited relatively low passive current densities; Co-Cr/Ti implant couples the highest. Co-Cr and Ni-Cr/Ti implant couples showed breakdown potentials of 700 and 570 mV (SCE), respectively. The open-circuit potentials of silver, Ti abutment, gold, Ni-Cr, and Co-Cr/Ti implant couples were -93.2 +/- 93.9, -123.7 +/- 58.8, -140.0 +/- 80.6, -223.5 +/- 35.1, and -312.7 +/- 29.8 mV (SCE), respectively, and did not change with immersion time. The couples exhibited cathodic current densities at -250 mV (SCE); in particular, gold and silver alloys showed high cathodic current densities of -3.18 and -6.63 microA/cm(2), respectively. At 250 mV (SCE

  14. NGBAuth - Next Generation Batch Authentication for long running batch jobs.

    CERN Document Server

    Juto, Zakarias

    2015-01-01

    This document describes the prototyping of a new solution for the CERN batch authentication of long running jobs. While the job submission requires valid user credentials, these have to be renewed due to long queuing and execution times. Described within is a new system which will guarantee a similar level of security as the old LSFAuth while simplifying the implementation and the overall architecture. The new system is being built on solid, streamlined and tested components (notably OpenSSL) and a priority has been to make it more generic in order to facilitate the evolution of the current system such as for the expected migration from LSF to Condor as backend batch system.

  15. Efeito do tipo de revestimento na soldagem a ponto de aços galvanizados Effect of coating type on spot welding of galvanized steel

    Directory of Open Access Journals (Sweden)

    Tarcélio Anício da Silva

    2010-09-01

    -Cu (brass. Spot welding tests were carried out in IF steels coated in an industrial hot-dip galvanizing line with pure zinc (GI and a Zn-Fe alloy (GA. Three welding joints were evaluated: GA/GA, GI/GI and GA/GI. Dynamic weldability diagrams and electrode life were determined for each kind of joint. The results indicated that welding current increased more quickly with the number of welds for the GI/ GI joints. This result was associated with the fastest contamination of the electrode by zinc. For the GA/GI joints, welding current levels for adequate welding increased faster than for GA/GA joints but slower than for GI/GI joints. In general, the spot welding tests with GA/GI joints presented results closer to that of the GA/GA joints than to the spot welding tests with GI/GI joints. Such results showed the positive influence of the GA coating, even for joints including both coatings to improve the spot weldability of zinc coated steels.

  16. Impact of Music on College Students: Analysis of Galvanic Skin Responses

    Directory of Open Access Journals (Sweden)

    Atefeh GOSHVARPOUR

    2014-12-01

    Full Text Available Purpose: The impact of music on the human body is an important trend in music research. Different kinds of music have direct and indirect effects on physiological functions and parameters in normal and pathological conditions. Among various physiological measurements, the galvanic skin response is a noninvasive, useful, simple and reproducible method of capturing the autonomic nerve response. The aim of this study is to evaluate the effect of Persian music on galvanic skin response. Basic methods: Galvanic skin response signals of 25 college students (10 women and 15 men were collected. Mean, amplitude, rise time and Lyapunov exponents of the signals were calculated. Main results: The results show that not only the galvanic skin response amplitude is higher in men subjects during rest, but it also increased to the higher values during music than that of women. In addition, the fluctuations of it increased during music in men group; while it decreased in women group. The positive values of Lyapunov exponents suggest that all galvanic skin responses have low dimensional chaos. In addition, the complexity of galvanic skin responses is decreased during music. Conclusions: Our study has shown that the same music protocol has different reflections on the galvanic skin response of women and men. Furthermore, the proposed method may serve as a quantitative measure for emotional states such as listening to the music.

  17. Galvanic effects on cavitation damage for 1Cr13 stainless steel

    Institute of Scientific and Technical Information of China (English)

    Dongbai Sun; Xia Bai; Hongying Yu; Huimin Meng; Huiqing Li

    2003-01-01

    Based on the electric-spark principle, a new kind of cavitation damage testing apparatus was designed, which could produce the bubble. Bubbles collapsed and acted on a small surface area of the alloy surface, so an intensive electrochemical inhomoge nous state would be induced and lead to the existence of surface galvanic effect on the alloy. The galvanic effect of 1Cr13 SS during cavitation damage has been quantitatively investigated in NaCl solution. The results show that intensive galvanic effect of 1Crl3 SS during cavitation damage appears the potential of the damaged area shifting negatively with the bubble collapse and simultaneously the galvanic current generates. The mass loss of alloy due to cavitation increases with the bubble quantity, and increases with the in creasing of Cl- content. And both the total mass loss and the mass loss due to galvanic corrosion increase linearly with the area ratio of cavitation damaged to undamaged area. Such surface galvanic effects speed up the dissolution rate of the alloy, which, in turn, accelerates the mechanical damage, and aggravates the mass loss of the alloy. It has been further confirmed that the mass loss due to the surface galvanic effect can be decreased by catholic protection.

  18. Immune markers in oral discomfort patients before and after elimination of oral galvanism.

    Science.gov (United States)

    Podzimek, Stepan; Tomka, Milan; Sommerova, Pavla; Lyuya-Mi, Yelena; Bartova, Jirina; Prochazkova, Jarmila

    2013-01-01

    An enhanced release of metals in the mouth due to galvanic cell formation is considered to be one of the causes of oral discomfort. The aim of this study was to investigate the influence of galvanic cell on salivary immune defense factors. The levels of IgA1, IgA2, sIgA, lysozyme and antiIgA/HSP60 were evaluated in representative samples from 159 patients with galvanism, from 177 patients without galvanism and in two control groups. All the participants underwent personal history taking, clinical examination, galvanic currents measurement and saliva collection. Electro active dental materials were removed in 30 patients. There was a significant increase in IgA2 level, a significant decrease in antiIgA/HSP60 levels and an increase in IgA1, sIgA and lysozyme levels found after the removal of electro active restorations. Morphological symptoms disappeared in 70% of the treated patients. The study confirmed that pathologic galvanic phenomena influences the immune defense reactions in the oral cavity and thus may cause the symptoms of oral discomfort. A measurement of the galvanism and a subsequent removal of electro active restorations should become a common therapeutic procedure in the patients with oral discomfort.

  19. Galvanic zinc-copper microparticles inhibit melanogenesis via multiple pigmentary pathways.

    Science.gov (United States)

    Won, Yen-Kim; Lin, Connie B; Seiberg, Miri; Chen, Nannan; Hu, Yaping; Rossetti, Dianne; Saliou, Claude; Loy, Chong-Jin

    2014-01-01

    The endogenous electrical field of human skin plays an important role in many skin functions. However, the biological effects and mechanism of action of externally applied electrical stimulation on skin remain unclear. Recent study showed that galvanic zinc-copper microparticles produce electrical stimulation and reduce inflammatory and immune responses in intact skin, suggesting the important role of electrical stimulation in non-wounded skin. The objective of this study is to investigate the biological effect of galvanic zinc-copper microparticles on skin pigmentation. Our findings showed that galvanic zinc-copper microparticles inhibited melanogenesis in a human melanoma cell line (MNT-1), human keratinocytes and melanoma cells co-cultures, and in pigmented epidermal equivalents. Treatment of galvanic zinc-copper microparticles inhibited melanogenesis by reducing the promoter transactivation of tyrosinase and tyrosinase-related protein-1 in human melanoma cells. In a co-culture Transwell system of keratinocytes and melanoma cells, galvanic zinc-copper microparticles reduced melanin production via downregulation of endothelin-1 secretion from keratinocytes and reduced tyrosinase gene expression in melanoma cells. In addition, exposure of pigmented epidermal equivalents to galvanic zinc-copper microparticles resulted in reduced melanin deposition. In conclusion, our data demonstrated for the first time that galvanic zinc-copper microparticles reduced melanogenesis in melanoma cells and melanin deposition in pigmented epidermal equivalents by affecting multiple pigmentary pathways.

  20. 77 FR 17029 - Certain Steel Nails From the United Arab Emirates: Final Determination of Sales at Less Than Fair...

    Science.gov (United States)

    2012-03-23

    ... in vinyl, zinc (galvanized, whether by electroplating or hot-dipping one or more times), phosphate... materials or conversion to judicial protective order is hereby requested. Failure to comply with...

  1. 76 FR 16379 - Certain Steel Nails From the People's Republic of China: Final Results of the First Antidumping...

    Science.gov (United States)

    2011-03-23

    ... vinyl, zinc (galvanized, whether by electroplating or hot-dipping one or more times), phosphate cement.... Timely written notification of the return/destruction of APO materials or conversion to...

  2. Batch-oriented software appliances

    CERN Document Server

    Murri, Riccardo

    2012-01-01

    This paper presents AppPot, a system for creating Linux software appliances. AppPot can be run as a regular batch or grid job and executed in user space, and requires no special virtualization support in the infrastructure. The main design goal of AppPot is to bring the benefits of a virtualization-based IaaS cloud to existing batch-oriented computing infrastructures. In particular, AppPot addresses the application deployment and configuration on large heterogeneous computing infrastructures: users are enabled to prepare their own customized virtual appliance for providing a safe execution environment for their applications. These appliances can then be executed on virtually any computing infrastructure being in a private or public cloud as well as any batch-controlled computing clusters the user may have access to. We give an overview of AppPot and its features, the technology that makes it possible, and report on experiences running it in production use within the Swiss National Grid infrastructure SMSCG.

  3. NDA Batch 2002-13

    Energy Technology Data Exchange (ETDEWEB)

    Hollister, R

    2009-09-17

    QC sample results (daily background check drum and 100-gram SGS check drum) were within acceptance criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on drum LL85501243TRU. Replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. HWM NCAR No. 02-1000168 issued on 17-Oct-2002 regarding a partially dislodged Cd sheet filter on the HPGe coaxial detector. This physical geometry occurred on 01-Oct-2002 and was not corrected until 10-Oct-2002, during which period is inclusive of the present batch run of drums. Per discussions among the Independent Technical Reviewer, Expert Reviewer and the Technical QA Supervisor, as well as in consultation with John Fleissner, Technical Point of Contact from Canberra, the analytical results are technically reliable. All QC standard runs during this period were in control. Data packet for SGS Batch 2002-13 generated using passive gamma-ray spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with establiShed control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable.

  4. 间歇结晶过程的分批优化%Batch-to-batch Optimization of Batch Crystallization Processes

    Institute of Scientific and Technical Information of China (English)

    Woranee Paengjuntuek; Paisan Kittisupakorn; Amornchai Arpornwichanop

    2008-01-01

    It is the fact that several process parameters are either unknown or uncertain. Therefore, an optimal control profile calculated with developed process models with respect to such process parameters may not give an optimal performance when implemented to real processes. This study proposes a batch-to-batch optimization strat-egy for the estimation of uncertain kinetic parameters in a batch crystallization process of potassium sulfate produc-tion. The knowledge of a crystal size distribution of the product at the end of batch operation is used in the proposedmethodology. The updated kinetic parameters are applied for determining an optimal operating temperature policy for the next batch run.

  5. Some relationships between punishment, stuttering, and galvanic skin responses.

    Science.gov (United States)

    Reed, C G; Lingwall, J B

    1976-06-01

    The simultaneous effects of response-contingent punishment on stuttering behaviors and the frequency of galvanic skin response (GSR) deflections for 10 subjects were investigated. GSR's and stuttering responses were recorded during base rate, treatment, and extinction conditions. The subjects demonstrated a 50% or greater decrease in stuttering frequency during the treatment condition. Combined data for all subjects indicated that the mean frequency of GSR deflections remained stable or declined across conditions of the study. Analysis of individual data revealed that GSR deflections during treatment as compared with base rate increased for four subjects, remained essentially the same in two subjects, and decreased for four subjects. These results suggest that experimental procedures which result in functional punishment effects on stuttering frequency may not be associated with any predictable pattern on concomitant autonomic arousal.

  6. Corrosion of bare and galvanized steel in gypsum

    Directory of Open Access Journals (Sweden)

    Gómez, Mercedes

    1988-12-01

    Full Text Available Gypsum is a relatively low-cost building material much abounding in our country. When it is put in contact with steel, it may produce high corrosion rates due to its pH value (close to 7. This work reports the results obtained in studying the corrosion rates of bare and galvanized steel in contact with gypsum and plaster, as well as the influence curing thermal treatment applied to gypsum, enviromental relative humidity and addition of compounds with different natures and purposes may have in such process. In-situ observations, as well as the measurement of the Polarization Resistance and the weight loss have been used as measurement technics. From the results obtained it has been possible to deduce that galvanized steel has better behaviour in dry enviroments than bare steel in the same conditions and moist atmosphere induces proportionally more corrosion in galvanized steel than in bare one. Additions to gypsum do not modified these conclusions, though it may be pointed out that addition of nitrites or lime improves the behaviour of bare steel, while galvanized behaviour is not modified. The addition of lime is not recommended because phenomena of dilated along time expansion may take place.

    El yeso es un material de construcción de relativo bajo coste y que, además, es muy abundante en nuestro país. Debido a su pH cercano a la neutralidad, cuando entra en contacto con el acero, este puede corroerse a elevadas velocidades. En esta comunicación se presentan los resultados de un estudio sobre la velocidad de corrosión del acero desnudo y galvanizado en contacto con yeso y escayola y la influencia que tienen: el tratamiento térmico del curado del yeso, la humedad relativa ambiental y la adición de aditivos de diversa naturaleza y finalidad. Como técnicas de medida se han utilizado la medida de la Resistencia de Polarización y de la pérdida de peso, así como observaciones visuales. De los resultados se puede deducir que en

  7. Electrode Architecture in Galvanic and Electrolytic Energy Cells.

    Science.gov (United States)

    Jeong, Beomgyun; Ocon, Joey D; Lee, Jaeyoung

    2016-04-11

    Electrodes in galvanic and electrolytic energy cells are complicated structures comprising redox-active materials, ionic/electronic conductors, and porous pathways for mass transfer of reactants. In contrast to breakthroughs in component development, methods of optimizing whole-system architectural design to draw maximum output have not been well explored. In this Minireview, we introduce generalized types of electrode architecture, discuss fabrication strategies, and characterize already built structures. Systematic efforts to discover optimal electrode configurations will resolve long-standing discrepancies that arise between whole systems and the sums of their parts for a number of electrochemical reactions and technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Fatigue Properties of Galvanized Higher-Strength Steel Sheets

    Directory of Open Access Journals (Sweden)

    Buršák, M.

    2007-01-01

    Full Text Available The paper analyzes the fatigues properties of galvanized microalloyed steel sheets H220LAD and H380LAD. Under flat bending conditions and the symmetrical cycle, the fatigue limit of the H220LAD sheet is σCo = ± 152 MPa and that of the H380LAD sheet is σCo = ±188 MPa, and the fatigue limit to tensile strength ratio is 0,41 and 0,37, respectively. During fatigue tests with an increasing number of cycles or an increasing stress value, the degradation of the zinc coating increases (relief formation, damage of integrity. As a result, local corrosion, but also continuation of fatigue damage after 107 cycles, and hence corrosion fatigue, can take place during operation.

  9. Laser brazing with filler wire for galvanized steel sheets

    Institute of Scientific and Technical Information of China (English)

    Feng Xiaosong; Li Liqun; Chen Yanbin; Zhou Shanbao

    2005-01-01

    The process properties and interface behavior of CO2 laser brazing with automatic wire feed for galvanized steel sheets were investigated , in which the brazing filler metal was CuSi3 and no flux was used. As to the appearance quality of the brazing seams, the roles of the processing parameters, such as brazing speed, wire feeding rate, inclination and feeding direction of the wire, laser power, spot diameter and heating position, were assessed. The further investigation indicates that the behavior of the active elements Si, Mn and Zn are significantly influenced by energy input. At the interface, the microstructure of the base metal was composed of columnar crystals and the acicalar α solid solution was found on the filler metal side.

  10. Liquid Galvanic Coatings for Protection of Imbedded Metals

    Science.gov (United States)

    MacDowell, Louis G. (Inventor); Curran, Joseph J. (Inventor)

    2003-01-01

    Coating compositions and methods of their use are described herein for the reduction of corrosion in imbedded metal structures. The coatings are applied as liquids to an external surface of a substrate in which the metal structures are imbedded. The coatings are subsequently allowed to dry. The liquid applied coatings provide galvanic protection to the imbedded metal structures. Continued protection can be maintained with periodic reapplication of the coating compositions, as necessary, to maintain electrical continuity. Because the coatings may be applied using methods similar to standard paints, and because the coatings are applied to external surfaces of the substrates in which the metal structures are imbedded, the corresponding corrosion protection may be easily maintained. The coating compositions are particularly useful in the protection of metal-reinforced concrete.

  11. Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires

    National Research Council Canada - National Science Library

    Marcello Gelfi; Luigi Solazzi; Sandro Poli

    2017-01-01

    This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process...

  12. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  13. GALVANIC CORROSION AND PROTECTION OF GECM/LY12CZ COUPLES UNDER DIFFERENT ATMOSPHERIC EXPOSURE CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    F. Lu; Q.P. Zhong; C.X. Cao

    2003-01-01

    Galvanic compatibility between graphite epoxy composite materials (GECM) andLY12CZ aluminum alloy was evaluated in different atmospheric corrosion environ-ments and by laboratory electrochemical measurements. Open circuit potential elec-trochemical measurements showed a relatively large potential difference about 1 voltbetween the GECM and LY12CZ aluminum alloy, and this difference provided thedriving force for galvanic corrosion of the LY12CZ aluminum alloy as an anode.Having been exposed for 1, 3 or 5 years in Beijing, Tuandao and Wanning station,GECM/L Y12CZ couples showed significant losses of strength and elongation. Protec-tive coatings and non-conductive barriers breaking the galvanic corrosion circuit wereevaluated under the same atmospheric corrosive conditions. Epoxy primer paint, glasscloth barriers and LY12CZ anodizing were effective in galvanic corrosion control forGECM/L Y12CZ couples.

  14. BATCH SETTLING IN VERTICAL SETTLERS

    OpenAIRE

    Lama Ramirez, R.; Universidad Nacional Mayor De San Marcos Facultad de Química e Ingeniería Química Departamento de Operaciones Unitarias Av. Venezuela cdra. 34 sin, Lima - Perú; Condorhuamán Ccorimanya, C.; Universidad Nacional Mayor De San Marcos Facultad de Química e Ingeniería Química Departamento de Operaciones Unitarias Av. Venezuela cdra. 34 sin, Lima - Perú

    2014-01-01

    lt has been studied the batch sedimentation of aqueous suspensions of precipitated calcium carbonate, barium sulphate and lead oxide , in vertical thickeners of rectangular and circular cross sectional area. Suspensions vary in concentration between 19.4 and 617.9 g/I and the rate of sedimentation obtained between 0.008 and 7.70 cm/min. The effect of the specific gravity of the solid on the rate of sedimentation is the same for all the suspensions, that is, the greater the value of the specif...

  15. Polyfibroblast Phase 4: A Self-Healing and Galvanic Protection Additive

    Science.gov (United States)

    2014-11-26

    8/98) Prescribed by ANSI Std. Z39.18 REDD-2014-387 POLYFIBROBLAST PHASE IV: A SELF- HEALING AND GALVANIC PROTECTION ADDITIVE Progress Report #10...Performance/Technical Report (Monthly) 4. TITLE AND SUBTITLE Polyfibroblast: A Self- Healing and Galvanic Protection Additive 6. AUTHOR{S) Benkoski, Jason...14. ABSTRACT The goal of this project is to develop a primer additive that mimics the self- healing ability of skin by forming a polymer scar across

  16. [Effect of retroauricular galvanic stimulation on the central vestibular system--immunohistochemical evaluation of GABA].

    Science.gov (United States)

    Okami, K; Sekitani, T

    1990-03-01

    The changes of the neurotransmitter (GABA) distribution in the brain stem of the rats by retroauricular galvanic stimulation were investigated using immunohistochemical method. Twenty-one rats were divided into two groups: the control group which received no galvanic stimulation, and the galvanically stimulated group which received anodal galvanic stimulation (unipolar monoauricular, 5 mA in intensity, 500 msec of duration, 1 Hz in frequency) for 30 minutes. The specimens obtained as usual strict procedure for histological investigation were stained immunohistochemically using antisera against GABA. The results were as follows: 1. In the control group, GABA-like immunoreactivity was observed in all four main vestibular nuclei. In the superior, medial, and descending vestibular nuclei GABA-like immunoreactivity was found in the small cells and the terminals. Giant cells in the lateral vestibular nucleus were surrounded by GABA immunoreactive terminals. 2. In the galvanically stimulated group GABA-like immunoreactivity showed recognizable laterality in the lateral vestibular nucleus where GABA-like immunoreactivity surrounding giant cells showed more intensive on the side ipsilateral to the stimulation compared with the opposite side. On the other hand GABA-like immunoreactivity showed no laterality in the superior, medial, and descending vestibular nuclei. 3. It can be concluded that the retroauricular galvanic stimulation cause some changes in the inhibitory activity of the lateral vestibulo-spinal tract and of the spinal motor neuron.

  17. Understanding the nature of the manganese hot dip phosphatizing process of steel

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado M, G.; Fuentes A, J. C.; Salinas R, A.; Rodriguez V, F. J., E-mail: juan.fuentes@cinvestav.edu.mx [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Saltillo, Av. Industria Metalurgica No. 1062, Parque Industrial Ramos Arizpe, 25900 Saltillo, Coahuila (Mexico)

    2013-07-01

    In this work, the phosphatizing process of steel is investigated using open circuit potential and Tafel curves as well as scanning electron microscopy and energy dispersive X-ray spectroscopy. The results reveal that a ph of 2.57 in the phosphatizing solution promotes the dissociation of phosphoric acid which assist the formation of the manganese tertiary salt (Mn{sub 3}(PO{sub 4}){sub 2}), which is deposited on the substrate. It was also observed that an increase in the temperature from 25 to 90 C and the presence of HNO{sub 3} as catalysts enhances the manganese phosphatizing kinetics. On the other hand, the generation of iron phosphates and oxides is predominant at a ph of 1 and 90 C. These observations are supported by species distribution and Pourbaix thermodynamic diagrams. (Author)

  18. Complex Boronized Layer on the Hot-dip Aluminized Steels and Its Surface Performances

    Institute of Scientific and Technical Information of China (English)

    LUOXin-min; LIDian-kai; WANGLan; CHENKang-min

    2004-01-01

    Plain carbon steels were dipped in molten aluminum bath at 720℃±5℃ and diffused for 1.2.5 and 6 hours respectively and then horonized at 950℃ for 6 hours. The oxidation, hot-corrosion and abrasion resistance behavior were examined. The experimental results showed the compounds of the aluminized layer, from the surface to the matrix, were composed of Fe2Al5(η-phase/.Fe3Al(β1-phase)and α phase. The microstructure of aluminized plus complex boronized were similar to that simplex boronized. The XRD analysis results indicated that there existed Fe.B. Fe2AlB2 and Fe2Al5 in this kind of layer, The simplex aluminized layers still remained bright gray appearance when oxidized at 950℃, but complex horonized layer was not able to resist oxidization at the temperature. Both the layers of complex botanized and aluminized had the same anti-oxidizatian level in the circulative oxidization tesfs, and also good anti-corrosion abilily in molten salt medium. Under dry abrasive conditions, wear resistance of complex botanized layer was superior to the aluminized layer.

  19. Complex Boronized Layer on the Hot-dip Aluminized Steels and Its Surface Performances

    Institute of Scientific and Technical Information of China (English)

    LUO Xin-min; LI Dian-kai; WANG Lan; CHEN Kang-min

    2004-01-01

    Plain carbon steels were dipped in molten aluminum bath at 720℃±5℃ and diffused for 1, 2.5 and 6 hours respectively and then boronized at 950℃ for 6 hours. The oxidation, hot-corrosion and abrasion resistance behavior were examined. The experimental results showed the compounds of the aluminized layer, from the surface to the matrix, were composed of Fe2Al5 ( η -phase )、 Fe3Al ( β 1-phase ) and α phase. The microstructure of aluminized plus complex boronized were similar to that simplex boronized. The XRD analysis results indicated that there existed Fe2B、 Fe2AlB2 and Fe2Al5 in this kind of layer. The simplex aluminized layers still remained bright gray appearance when oxidized at 950℃, but complex boronized layer was not able to resist oxidization at the temperature. Both the layers of complex boronized and aluminized had the same anti-oxidization level in the circulative oxidization tests, and also good anti-corrosion ability in molten salt medium. Under dry abrasive conditions, wear resistance of complex boronized layer was superior to the aluminized layer.

  20. Galvanic corrosion of Mg-Zr fuel cladding and steel immobilized in Portland cement and geopolymer at early ages

    Science.gov (United States)

    Rooses, Adrien; Lambertin, David; Chartier, David; Frizon, Fabien

    2013-04-01

    Galvanic corrosion behaviour of Mg-Zr alloy fuel cladding and steel has been studied in Ordinary Portland cement and Na-geopolymer. Portland cements implied the worse magnesium corrosion performances due to the negative effects of cement hydrates, grinding agents and gypsum on the galvanic corrosion. Galvanic corrosion in Na-geopolymer paste remains very low. Silicates and fluoride from the geopolymer activation solution significantly improve the corrosion resistance of the magnesium alloy while coupling with a cathode.

  1. In situ liquid-cell electron microscopy of silver-palladium galvanic replacement reactions on silver nanoparticles

    National Research Council Canada - National Science Library

    Sutter, E; Jungjohann, K; Bliznakov, S; Courty, A; Maisonhaute, E; Tenney, S; Sutter, P

    2014-01-01

    .... In situ observations by liquid-cell electron microscopy can provide insight into mechanisms, rates and possible modifications of galvanic replacement reactions in the native solution environment...

  2. Galvanic Cell Type Sensor for Soil Moisture Analysis.

    Science.gov (United States)

    Gaikwad, Pramod; Devendrachari, Mruthyunjayachari Chattanahalli; Thimmappa, Ravikumar; Paswan, Bhuneshwar; Raja Kottaichamy, Alagar; Makri Nimbegondi Kotresh, Harish; Thotiyl, Musthafa Ottakam

    2015-07-21

    Here we report the first potentiometric sensor for soil moisture analysis by bringing in the concept of Galvanic cells wherein the redox energies of Al and conducting polyaniline are exploited to design a battery type sensor. The sensor consists of only simple architectural components, and as such they are inexpensive and lightweight, making it suitable for on-site analysis. The sensing mechanism is proved to be identical to a battery type discharge reaction wherein polyaniline redox energy changes from the conducting to the nonconducting state with a resulting voltage shift in the presence of soil moisture. Unlike the state of the art soil moisture sensors, a signal derived from the proposed moisture sensor is probe size independent, as it is potentiometric in nature and, hence, can be fabricated in any shape or size and can provide a consistent output signal under the strong aberration conditions often encountered in soil moisture analysis. The sensor is regenerable by treating with 1 M HCl and can be used for multiple analysis with little read out hysteresis. Further, a portable sensor is fabricated which can provide warning signals to the end user when the moisture levels in the soil go below critically low levels, thereby functioning as a smart device. As the sensor is inexpensive, portable, and potentiometric, it opens up avenues for developing effective and energy efficient irrigation strategies, understanding the heat and water transfer at the atmosphere-land interface, understanding soil mechanics, forecasting the risk of natural calamities, and so on.

  3. Methanol oxidation at platinized copper particles prepared by galvanic replacement

    Directory of Open Access Journals (Sweden)

    Ioanna Mintsouli

    2016-04-01

    Full Text Available Bimetallic Pt-Cu particles have been prepared by galvanic replacement of Cu precursor nanoparticles, upon the treatment of the latter with a chloro-platinate acidic solution. The resulting particles, typically a few tens of nm large, were supported on high surface area carbon (Vulcan® XC–72R, Cabot and tested as electrodes. Surface electrochemistry in deaerated acid solutions was similar to that of pure Pt, indicating the existence of a Pt shell (hence the particles are denoted as Pt(Cu. Pt(Cu/C supported catalysts exhibit superior carbon monoxide and methanol oxidation activity with respect to their Pt/C analogues when compared on a per electroactive surface area basis, due to the modification of Pt activity by Cu residing in the particle core. However, as a result of large particle size and agglomeration phenomena, Pt(Cu/C are still inferior to Pt/C when compared on a mass specific activity basis.

  4. Counteracting Muscle Atrophy using Galvanic Stimulation of the Vestibular System

    Science.gov (United States)

    Fox, Robert A.; Polyakov, Igor

    1999-01-01

    The unloading of weight bearing from antigravity muscles during space flight produces significant muscle atrophy and is one of the most serious health problems facing the space program. Various exercise regimens have been developed and used either alone or in combination with pharmacological techniques to ameliorate this atrophy, but no effective countermeasure exists for this problem. The research in this project was conducted to evaluate the potential use of vestibular galvanic stimulation (VGS) to prevent muscle atrophy resulting from unloading of weight bearing from antigravity muscles. This approach was developed based on two concepts related to the process of maintaining the status of the anti-gravity neuromuscular system. These two premises are: (1) The "tone," or bias on spinal motorneurons is affected by vestibular projections that contribute importantly to maintaining muscle health and status. (2) VGS can be used to modify the excitability, or 'tone' of motorneuron of antigravity muscles. Thus, the strategy is to use VGS to modify the gain of vestibular projections to antigravity muscles and thereby change the general status of these muscles.

  5. Properties of Si Nanowires Synthesized by Galvanic Cell Reaction

    Science.gov (United States)

    Yasushi Kobayashi,; Sadao Adachi,

    2010-07-01

    A galvanic cell reaction is used to synthesize Si nanowires (SiNWs) in AgNO3/HF solution at 30 °C for 60 min. The AgNO3 concentration ise varied from M=0.0001 to 0.6 mol/L in aqueous HF solution (5 mol/L). Vertically well-aligned SiNW arrays are found to be formed in the limited AgNO3 concentration range of M˜ 0.02--0.08 mol/L. The maximum nanowire length is ˜35 μm (M˜ 0.05 mol/L). The photoluminescence (PL) spectra of the SiNWs exhibit a broad peak centered at ˜1.8 eV. Below M˜ 0.02 or above ˜0.08 mol/L, the solutions produce only roughened surfaces. No PL emission is observed from such surfaces. Passive HF etching of the SiNWs leads to the removal of the surface oxide overlayer and changes the wettability from highly hydrophilic (˜5°) to superhydrophobic (˜135°). Optical absorption and Fourier-transform infrared spectroscopy show that the SiNWs have an extremely large optical absorbability not only in the interband-transition region but also in the far-infrared spectral region.

  6. Counteracting Muscle Atrophy using Galvanic Stimulation of the Vestibular System

    Science.gov (United States)

    Fox, Robert A.; Polyakov, Igor

    1999-01-01

    The unloading of weight bearing from antigravity muscles during space flight produces significant muscle atrophy and is one of the most serious health problems facing the space program. Various exercise regimens have been developed and used either alone or in combination with pharmacological techniques to ameliorate this atrophy, but no effective countermeasure exists for this problem. The research in this project was conducted to evaluate the potential use of vestibular galvanic stimulation (VGS) to prevent muscle atrophy resulting from unloading of weight bearing from antigravity muscles. This approach was developed based on two concepts related to the process of maintaining the status of the anti-gravity neuromuscular system. These two premises are: (1) The "tone," or bias on spinal motorneurons is affected by vestibular projections that contribute importantly to maintaining muscle health and status. (2) VGS can be used to modify the excitability, or 'tone' of motorneuron of antigravity muscles. Thus, the strategy is to use VGS to modify the gain of vestibular projections to antigravity muscles and thereby change the general status of these muscles.

  7. Galvanic corrosion behavior of titanium implants coupled to dental alloys.

    Science.gov (United States)

    Cortada, M; Giner, L; Costa, S; Gil, F J; Rodríguez, D; Planell, J A

    2000-05-01

    The corrosion of five materials for implant suprastructures (cast-titanium, machined-titanium, gold alloy, silver-palladium alloy and chromium-nickel alloy), was investigated in vitro, the materials being galvanically coupled to a titanium implant. Various electrochemical parameters E(CORR), i(CORR) Evans diagrams, polarization resistance and Tafel slopes) were analyzed. The microstructure of the different dental materials was observed before and after corrosion processes by optical and electron microscopy. Besides, the metallic ions released in the saliva environment were quantified during the corrosion process by means of inductively coupled plasma-mass spectrometry technique (ICP-MS). The cast and machined titanium had the most passive current density at a given potential and chromium-nickel alloy had the most active critical current density values. The high gold content alloys have excellent resistance corrosion, although this decreases when the gold content is lower in the alloy. The palladium alloy had a low critical current density due to the presence of gallium in this composition but a selective dissolution of copper-rich phases was observed through energy dispersive X-ray analysis.

  8. A Galvanic Sensor for Monitoring the Corrosion Condition of the Concrete Reinforcing Steel: Relationship Between the Galvanic and the Corrosion Currents

    Directory of Open Access Journals (Sweden)

    Elsa Vaz Pereira

    2009-10-01

    Full Text Available This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. Sensors have been tested in saturated Ca(OH2 aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O2. For all the conditions, the influence of temperature (20 to 55 ºC has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the Rp values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the Igal, indicative of the state condition of the reinforcing steel for the designed sensor, were established.

  9. A galvanic sensor for monitoring the corrosion condition of the concrete reinforcing steel: relationship between the galvanic and the corrosion currents.

    Science.gov (United States)

    Pereira, Elsa Vaz; Figueira, Rita Bacelar; Salta, Maria Manuela Lemos; da Fonseca, Inês Teodora Elias

    2009-01-01

    This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, I(gal), and the corrosion currents, I(corr), estimated from the polarization resistance, R(p). Sensors have been tested in saturated Ca(OH)(2) aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O(2). For all the conditions, the influence of temperature (20 to 55 °C) has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the R(p) values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the I(gal), indicative of the state condition of the reinforcing steel for the designed sensor, were established.

  10. DFT study on the galvanic interaction between pyrite (100) and galena (100) surfaces

    Science.gov (United States)

    Ke, Baolin; Li, Yuqiong; Chen, Jianhua; Zhao, Cuihua; Chen, Ye

    2016-03-01

    The galvanic interaction between pyrite and galena surface has been investigated using density functional theory (DFT) method. The calculated results show that galvanic interactions between pyrite and galena surface are decreased with the increase of contact distance. The galvanic interactions still occurs even the distance larger than the sum of two atoms radius (≈2.8 Å), and the limit distance of galvanic interaction between galena and pyrite surface is about 10 Å, which is consistent with the quantum tunneling effect. Through Mulliken charge population calculation, it is found that electrons transfer from galena to pyrite. For galena surface, Pb 6s and 6p states lose electrons and S 3p state loses a small amount of electrons, which causes the electron loss of galena. For pyrite surface, Fe 4p state obtains large numbers of electrons, resulting in the decrease of positive charge of Fe atom. However, the 3p state of S atom loses a small numbers of electrons. The reactivity of mineral surface has also been studied by calculating the frontier orbitals of minerals. Results suggest that the highest occupied molecular orbital (HOMO) coefficients of galena are increased whereas those of pyrite are decreased with the enhancing galvanic interaction, indicating that the oxidation of galena surface would be enhanced due to the galvanic interaction. The Fukui indices and dual descriptor values of surface atoms suggest that the nucleophilicity of the galena surface increases, meanwhile, the electrophilicity of pyrite surface increases with the decrease of the contact distance. In addition, the density of states (DOS) of atoms results show that the activity of electrons in Pb 6s and 6p orbitals enhances while the activity of electrons in Fe 3d orbitals weaken due to the galvanic contact between minerals.

  11. Following an Optimal Batch Bioreactor Operations Model

    DEFF Research Database (Denmark)

    Ibarra-Junquera, V.; Jørgensen, Sten Bay; Virgen-Ortíz, J.J.;

    2012-01-01

    The problem of following an optimal batch operation model for a bioreactor in the presence of uncertainties is studied. The optimal batch bioreactor operation model (OBBOM) refers to the bioreactor trajectory for nominal cultivation to be optimal. A multiple-variable dynamic optimization of fed-b...

  12. Family based dispatching with batch availability

    NARCIS (Netherlands)

    van der Zee, D.J.

    2013-01-01

    Family based dispatching rules seek to lower set-up frequencies by grouping (batching) similar types of jobs for joint processing. Hence shop flow times may be improved, as less time is spent on set-ups. Motivated by an industrial project we study the control of machines with batch availability, i.e

  13. Supervision of Fed-Batch Fermentations

    DEFF Research Database (Denmark)

    Gregersen, Lars; Jørgensen, Sten Bay

    1999-01-01

    Process faults may be detected on-line using existing measurements based upon modelling that is entirely data driven. A multivariate statistical model is developed and used for fault diagnosis of an industrial fed-batch fermentation process. Data from several (25) batches are used to develop a mo...

  14. Automatic Endpoint Determination for Batch Tea Dryers

    NARCIS (Netherlands)

    Temple, S.J.; Boxtel, van A.J.B.

    2000-01-01

    Agricultural Engineering and Physics, Wageningen University, Bomenweg 4, Wageningen, 6703 HD, The Netherlands Abstract: A laboratory batch fluid-bed dryer was developed for handling small samples of tea for experimental batch manufacture, and this dryer required a means of stopping drying when the p

  15. Automatic endpoint determination for batch tea dryers

    NARCIS (Netherlands)

    Temple, S.J.; Boxtel, van A.J.B.

    2001-01-01

    A laboratory batch fluid-bed dryer was developed for handling small samples of tea for experimental batch manufacture, and this dryer required a means of stopping drying when the process was complete. A control system was devised which requires only the initial weight of the sample to be entered

  16. Norton's theorem for batch routing queueing networks

    NARCIS (Netherlands)

    Bause, Falko; Boucherie, Richard J.; Buchholz, Peter

    2001-01-01

    This paper shows that the aggregation and decomposition result known as Norton’s theorem for queueing networks can be extended to a general class of batch routing queueing networks with product-form solution that allows for multiple components to simultaneously release and receive (batches of) custo

  17. A Noble Approach of Process Automation in Galvanized Nut, Bolt Manufacturing Industry

    Directory of Open Access Journals (Sweden)

    Akash Samanta

    2012-05-01

    Full Text Available Corrosion costs money”, The Columbus battle institute estimates that corrosion costs Americans more than $ 220 billion annually, about 4.3% of the gross natural product [1].Now a days due to increase of pollution, the rate of corrosion is also increasing day-by-day mainly in India, so, to save the steel structures, galvanizing is the best and the simplest solution. Due to this reason galvanizing industries are increasing day-by-day since mid of 1700s.Galvanizing is a controlled metallurgical combination of zinc and steel that can provide a corrosion resistance in a wide variety of environment. In fact, the galvanized metal corrosion resistance factor can be some 70 to 80 times greater that the base metal material. Keeping in mind the importance of this industry, a noble approach of process automation in galvanized nut-bolt  manufacturing plant is presented here as nuts and bolts are the prime ingredient of any structure. In this paper the main objectives of any industry like survival, profit maximization, profit satisfying and sales growth are fulfilled. Furthermore the environmental aspects i.e. pollution control and energy saving are also considered in this paper. The whole automation process is done using programmable logic controller (PLC which has number of unique advantages like being faster, reliable, requires less maintenance and reprogrammable. The whole system has been designed and tested using GE, FANUC PLC.

  18. Examination of Galvanic Action between Fe-Based Bulk Metallic Glass and Crystalline Alloys

    Science.gov (United States)

    Ha, Hung M.; Payer, Joe H.

    2009-06-01

    Fe-based bulk metallic glasses (amorphous metals) have been developed, and several compositions are shown to have excellent corrosion resistance in chloride solutions. Further, thermal-spray amorphous metals are being developed for use as a barrier coating layer, to protect substrate materials from corrosion. Galvanic action between dissimilar metals and the coating/substrate for the amorphous-alloy coatings is of practical interest for a number of applications. The mixed-potential theory provides a useful approach for examining the corrosion behavior of the component materials in the galvanic couple and is applied in this study. Galvanic action was studied for an Fe-based structurally amorphous metal (SAM) 1651 and several crystalline alloys that included 1018 C-steel, stainless steel (SS) 316L, and alloy 22. Anodic and cathodic polarization curves of each of the metals were measured by potentiodynamic polarization. Based on the mixed-potential theory, the behavior of the component materials in a galvanic cell was predicted. The predictions are compared to the measured behavior of galvanic couples with the crystalline alloys.

  19. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

    Science.gov (United States)

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-01-01

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

  20. Operation of a Batch Stripping Distillation Column

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of somecontrol tuning parameters on the column performance are discussed.

  1. Consequence Identification for Maloperation in Batch Process

    Institute of Scientific and Technical Information of China (English)

    张玉良; 张贝克; 马昕; 曹柳林; 吴重光

    2013-01-01

    Batch processes are important in chemical industry, in which operators usually play a major role and hazards may arise by their inadvertent acts. In this paper, based on hazard and operability study and concept of qualitative simulation, an automatic method for adverse consequence identification for potential maloperation is proposed. The qualitative model for production process is expressed by a novel directed graph. Possible operation deviations from normal operating procedure are identified systematically by using a group of guidewords. The pro-posed algorithm is used for qualitative simulation of batch processes to identify the effects of maloperations. The method is illustrated with a simple batch process and a batch reaction process. The results show that batch processes can be simulated qualitatively and hazards can be identified for operating procedures including maloperations. After analysis for possible plant maloperations, some measures can be taken to avoid maloperations or reduce losses re-sulted from maloperations.

  2. Batch Scheduling a Fresh Approach

    Science.gov (United States)

    Cardo, Nicholas P.; Woodrow, Thomas (Technical Monitor)

    1994-01-01

    The Network Queueing System (NQS) was designed to schedule jobs based on limits within queues. As systems obtain more memory, the number of queues increased to take advantage of the added memory resource. The problem now becomes too many queues. Having a large number of queues provides users with the capability to gain an unfair advantage over other users by tailoring their job to fit in an empty queue. Additionally, the large number of queues becomes confusing to the user community. The High Speed Processors group at the Numerical Aerodynamics Simulation (NAS) Facility at NASA Ames Research Center developed a new approach to batch job scheduling. This new method reduces the number of queues required by eliminating the need for queues based on resource limits. The scheduler examines each request for necessary resources before initiating the job. Also additional user limits at the complex level were added to provide a fairness to all users. Additional tools which include user job reordering are under development to work with the new scheduler. This paper discusses the objectives, design and implementation results of this new scheduler

  3. Batch and Fed-Batch Fermentation System on Ethanol Production from Whey using Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2013-10-01

    Full Text Available Nowadays reserve of fossil fuel has gradually depleted. This condition forces many researchers to  find energy alternatives which is renewable and sustainable in the future. Ethanol derived from cheese industrial waste (whey using fermentation process can be a new perspective in order to secure both energy and environment. The aim of this study was  to compare the operation modes (batch and fed-batch of fermentation system on ethanol production from whey using Kluyveromyces marxianus. The result showed that the fermentation process for ethanol production by fed-batch system was higher at some point of parameters compared with batch system. Growth rate and ethanol yield (YP/S of fed-batch fermentation were 0.122/h and 0.21 gP/gS respectively; growth rate and ethanol yield (YP/S of batch fermentation were 0.107/h, and 0.12 g ethanol/g substrate, respectively. Based on the data of biomass and ethanol concentrations, the fermentation process for ethanol production by fed-batch system were higher at some point of parameters compared to batch system. Periodic substrate addition performed on fed-batch system leads the yeast growth in low substrate concentrations and consequently  increasing their activity and ethanol productivity. Keywords: batch; ethanol; fed-batch; fermentation;Kluyveromyces marxianus, whey

  4. Uneven batch data alignment with application to the control of batch end-product quality.

    Science.gov (United States)

    Wan, Jian; Marjanovic, Ognjen; Lennox, Barry

    2014-03-01

    Batch processes are commonly characterized by uneven trajectories due to the existence of batch-to-batch variations. The batch end-product quality is usually measured at the end of these uneven trajectories. It is necessary to align the time differences for both the measured trajectories and the batch end-product quality in order to implement statistical process monitoring and control schemes. Apart from synchronizing trajectories with variable lengths using an indicator variable or dynamic time warping, this paper proposes a novel approach to align uneven batch data by identifying short-window PCA&PLS models at first and then applying these identified models to extend shorter trajectories and predict future batch end-product quality. Furthermore, uneven batch data can also be aligned to be a specified batch length using moving window estimation. The proposed approach and its application to the control of batch end-product quality are demonstrated with a simulated example of fed-batch fermentation for penicillin production. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Batch process. Changes and problems of a batch process; Bacchi prosesu no hensen to kadai

    Energy Technology Data Exchange (ETDEWEB)

    Niwa, T. [Asahi Engineering (Japan)

    1997-09-05

    One of the characteristics of the manufacture of fine chemical products is multikind production. The life cycles of chemical industrial products have become shorter, and the difference between these life cycles and those of the manufacturing facility has become larger. The use of an FMS (Flexible Manufacturing System) has been demanded as the measure for solving the problems, and the advantages of a batch process have begun to be reconsidered. This paper describes the history of the development of a batch process, and then explains the problems of a batch process. The paper mentions the process control techniques, production information control systems, production support systems, training systems and process simulation systems as the main techniques supporting the development of a batch process. The paper mentions the modeling and standardizing of a batch process, systematic batch process designing methods and the modeling of a production control information system as the problems of a batch process. 8 refs., 5 figs., 2 tabs.

  6. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  7. GALVANIC CORROSION AND PROTECTION OF GECM/LY12CZ COUPLES UNDER DIFFERENT ATMOSPHERIC EXPOSURE CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    F.Lu; Q.P.Zhong; 等

    2003-01-01

    Galvanic compatibility between graphite epoxy composite materials (GECM) and LY12CZ aluminum alloy was evaluated in different atmospheric corrosion environ-ments and by laboratory electrochemical measurements.Open circuit potential elec-trochemical measurements showed a relatively large potemtial difference about 1 volt between the GECM and LY12CZ aluminum alloy,and this difference provided the driving force for galvanic corrosion of the LY12CZ aluminum alloy as an anode. Having been exposed for 1,3or 5years in Beijing,Tuandao and Wanning station,GECM/LY12CZ couples showed significant losses of strength and elongation.Protec-tive coatings and non-conductive barriers breaking the galvanic corrosion circuit were evaluated under the same atmospheric corrosive conditions.Epoxy primer paint,glass cloth barriers and LY12CZ anodizing were effective in glvanic corrosion control for GECM/LY12CZ couples.

  8. Thunderbolt in biogeochemistry: galvanic effects of lightning as another source for metal remobilization.

    Science.gov (United States)

    Schaller, Jörg; Weiske, Arndt; Berger, Frank

    2013-11-04

    Iron and manganese are relevant constituents of the earth's crust and both show increasing mobility when reduced by free electrons. This reduction is known to be controlled by microbial dissimilation processes. Alternative sources of free electrons in nature are cloud-to-ground lightning events with thermal and galvanic effects. Where thermal effects of lightning events are well described, less is known about the impact of galvanic lightning effects on metal mobilization. Here we show that a significant mobilization of manganese occurs due to galvanic effects of both positive and negative lightning, where iron seems to be unaffected with manganese being abundant in oxic forms in soils/sediments. A mean of 0.025 mmol manganese (negative lightning) or 0.08 mmol manganese (positive lightning) mobilization may occur. We suggest that lightning possibly influences biogeochemical cycles of redox sensitive elements in continental parts of the tropics/subtropics on a regional/local scale.

  9. Pure metal extraction from molten oxide slag by short-circuit galvanic cell

    Institute of Scientific and Technical Information of China (English)

    Yunming Gao; Xingmin Guo; Kuochih Chou

    2004-01-01

    The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]Fe+C saturation|ZrO2(MgO)|(FeO)(siag) |Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.

  10. Geochemical investigation of the galvanic effects during oxidation of pyrite and base-metals sulfides.

    Science.gov (United States)

    Chopard, Aurélie; Plante, Benoît; Benzaazoua, Mostafa; Bouzahzah, Hassan; Marion, Philippe

    2017-01-01

    Predicting the water quality at mine sites is of significant importance for developing mines with respect for the environment. Acid mine drainage (AMD) occurs when sulfides are in contact with oxygen and water, and several parameters and mechanisms influence final drainage quality. Galvanic interactions influence the reactivity of sulfide minerals, which act as semi-conductors. These galvanic interactions have been insufficiently studied in the context of AMD generation. In this study, the influence of pyrite on the reactivity of sphalerite and chalcopyrite was investigated. Five blends, comprised of free grains of quartz/pyrite, quartz/chalcopyrite, quartz/sphalerite, quartz/pyrite/chalcopyrite, and quartz/pyrite/sphalerite, were subjected to geochemical testing. Five weathering cells were monitored over a 200-day period during which they were leached twice weekly. Leachates were analyzed for pH, Eh, electrical conductivity, and sulfate and metal concentrations. The results of these analyses showed that galvanic interactions occurred between free sulfide grains. Pyrite was galvanically protected over the full testing period in the quartz/pyrite/chalcopyrite blend, and partially protected in the quartz/pyrite/sphalerite blend. Moreover, the release of Cu from chalcopyrite and Zn, Mn, and Cd from sphalerite was accelerated in the presence of pyrite. This work provides a better understanding of the influence of pyrite on chalcopyrite and sphalerite reactivity by highlighting the galvanic effects. In the future, to improve the reliability of AMD prediction tests, galvanic interactions should be considered in both the prediction of the acid generation potential and the estimation of metal and metalloid release rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Wear resistance of WC/Co HVOF-coatings and galvanic Cr coatings modified by diamond nanoparticles

    Science.gov (United States)

    Kandeva, M.; Grozdanova, T.; Karastoyanov, D.; Assenova, E.

    2017-02-01

    The efforts in the recent 20 years are related to search of ecological solutions in the tribotechnologies for the replacement of galvanic Cr coatings in the contact systems operating under extreme conditions: abrasion, erosion, cavitation, corrosion, shock and vibration loads. One of the solutions is in the composite coatings deposited by high velocity gas-flame process (HVOF). The present paper presents comparative study results for mechanical and tribological characteristics of galvanic Cr coatings without nanoparticles, galvanic Cr coatings modified by diamond nanoparticles NDDS of various concentration 0.6; 10; 15 и 20% obtained under three technological regimes, and composite WC-12Co coating. Comparative results about hardness, wear, wear resistance and friction coefficient are obtained for galvanic Cr-NDDS and WC-12Co coatings operating at equal friction conditions of dry friction on abrasive surface. The WC-12Co coating shows 5.4 to 7 times higher wear resistance compared to the galvanic Cr-NDDS coatings.

  12. Effects of surface treatments of galvanized steels on projection welding procedure

    Institute of Scientific and Technical Information of China (English)

    王敏; 王宸煜

    2003-01-01

    A group of projection welding experiments and joints tension-shear tests are carried out for cold-rolled steel sheets, galvanized steel sheets (GSS) without treatment, GSS with phosphating and GSS with surface greasing, respectively. The experimental results are regressively analyzed on the computers, then the projection welded joint tension-shear strength curve and the perfect welding currents range of each material are obtained. The results show that surface treatments of galvanized steels have effects on their spot weldabilities. Among the four kinds of materials, GSS with surface greasing have the worst spot weldability, for they need higher welding current and have a narrow welding current range.

  13. QUANTITATIVE STUDY ON GALVANIC EFFECTS DURING CAVITATION DAMAGE OF 1Cr13 STAINLESS STEEL

    Institute of Scientific and Technical Information of China (English)

    X.Bai; D.B.Sun; 等

    2003-01-01

    The influence of the surface galvanic effects of 1Cr13 SS during cavitation damage has been investigated in NaCl soutions.The results show that the solution concentration and area ratio of bubble unacted surface to the bubble-acted surface greatly influence the cavitation damage of the alloy.The surace galvanic effects can speed up the dissolution rate of the alloy,and the mass loss per area of the alloy increases linearly with the area ratio of bubble unacted surface to the bubble acted surface of the alloy.

  14. QUANTITATIVE STUDY ON GALVANIC EFFECTS DURING CAVITATION DAMAGE OF 1Cr13 STAINLESS STEEL

    Institute of Scientific and Technical Information of China (English)

    X.Bai; D.B.Sun; H.Y.Yu; X.L.Zhang

    2003-01-01

    The influence of the surface galvanic effects of 1Cr13 SS during cavitation damage hasbeen investigated in NaCl solutions. The results show that the solution concentrationand area ratio of bubble unacted surface to the bubble-acted surface greatly influencethe cavitation damage of the alloy. The surface galvanic effects can speed up thedissolution rate of the alloy, and the mass loss per area of the alloy increases linearlywith the area ratio of bubble unacted surface to the bubble acted surface of the alloy.

  15. 核电厂的电偶腐蚀%Galvanic Corrosion of Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    姜媛媛; 费克勋

    2014-01-01

    By researching corrosion failure cases of galvanic corrosion in nuclear power plant, the corrosion failure of galvanic corrosion were analyzed.And effective measures were adopted. It also provided some control methods and measures on anti-corrosion.%通过对国内某核电站设备发生的电偶腐蚀失效案例,分析引起电偶腐蚀发生的原因,以及采取的有效措施,最后对核电站电偶腐蚀提出腐蚀控制方法。

  16. Chemically modified thermal-spray zinc anodes for galvanic cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S. Jr.; Bullard, S.J.; Holcomb, G.R.; Russell, J.H.; Cramer, S.D.; Bennett, J.E.; Laylor, H.M.

    1999-12-01

    Humectants, substances that promote the retention of moisture, were applied to new and previously aged thermal-sprayed Zn anodes to improve the performance of galvanic cathodic protection systems. Anodes on steel-reinforced concrete were treated with aqueous solutions of the humectants lithium nitrate (LiNO{sub 3}) and lithium bromide (LiBr). LiBr was the most beneficial humectant, increasing the average galvanic current density of new thermal-sprayed Zn anodes by as much as a factor of six.

  17. Galvanic and stress corrosion of copper canisters in repository environment. A short review

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Koenig, M. [Studsvik Nuclear AB, Nykoeping (Sweden)

    2001-02-01

    The Swedish Nuclear Power Inspectorate, SKI, has studied different aspects of canister and copper corrosion as part of the general improvement of the knowledge base within the area. General and local corrosion has earlier been treated by experiments as well as by thermodynamic calculations. For completeness also galvanic and stress corrosion should be treated. The present work is a short review, intended to indicate areas needing further focus. The work consists of two parts, the first of which contains a judgement of statements concerning risk of galvanic corrosion of copper in the repository. The second part concerns threshold values for the stress intensity factor of stress corrosion in copper. A suggestion is given on how such values possibly could be measured for copper at repository conditions. In early investigations by SKB, galvanic corrosion is not mentioned or at least not treated. In later works it is treated but often in a theoretical way without indications of any further treatment or investigation. Several pieces of work indicate that further investigations are required to ensure that different types of corrosion, like galvanic, cannot occur in the repository environment. There are for example effects of grain size, grain boundary conditions, impurities and other factors that could influence the appearance of galvanic corrosion that are not treated. Those factors have to be considered to be completely sure that galvanic corrosion and related effects does not occur for the actual canister in the specific environment of the repository. The circumstances are so specific, that a rather general discussion indicating that galvanic corrosion is not probable just is not enough. Experiments should also be performed for verification. It is concluded that the following specific areas, amongst others, could benefit from further consideration. Galvanic corrosion of unbreached copper by inhomogeneities in the environment and in the copper metal should be addressed

  18. Comparison of galvanic displacement and electroless methods for deposition of gold nanoparticles on synthetic calcite

    Indian Academy of Sciences (India)

    Chamarthi K Srikanth; P Jeevanandam

    2012-11-01

    Gold nanoparticles have been deposited on synthetic calcite substrate by galvanic displacement reaction and electroless deposition methods. A comparative study has shown that electroless deposition is superior compared to galvanic displacement reaction for uniform deposition of gold nanoparticles on calcite. Characterization of the samples, prepared by two different deposition methods, was carried out by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy (FE–SEM) and diffuse reflectance spectroscopy (DRS) measurements. FE–SEM studies prove that smaller nanoparticles of gold are deposited uniformly on calcite if electroless deposition method was employed and DRS measurements show the characteristic surface plasmon resonance of gold nanoparticles.

  19. LSF usage for batch at CERN

    CERN Multimedia

    Schwickerath, Ulrich

    2007-01-01

    Contributed poster to the CHEP07. Original abstract: LSF 7, the latest version of Platform's batch workload management system, addresses many issues which limited the ability of LSF 6.1 to support large scale batch farms, such as the lxbatch service at CERN. In this paper we will present the status of the evaluation and deployment of LSF 7 at CERN, including issues concerning the integration of LSF 7 with the gLite grid middleware suite and, in particular, the steps taken to endure an efficient reporting of the local batch system status and usage to the Grid Information System

  20. Master-Batch Sector Develops Rapidly

    Institute of Scientific and Technical Information of China (English)

    Wu Lifeng

    2007-01-01

    @@ Plastic industry promotes the development of the master-batch sector The plastic processing industry in China has developed rapidly. The output is increasing rapidly and the quality is improving constantly.

  1. Batch process. Application of CAE technique to a batch process; Bacchi purosesu eno CAE gijutsu no tenkai

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Nakai, K.; Oba, S. [Aspentic Japan Co. Ltd. (Japan)

    1997-09-05

    This paper introduces recent topics of the application of the CAE technique to a batch process. A batch distillation modeling tool (BATCHFRAC) is aimed at modeling a distillation tower and a batch reactor for a batch process for fine chemical products, and is provided as an expanded additional function for ASPEN FLUS batch distillation. A batch process designing system (BATCH PLUS) is a comprehensive batch process simulator for efficiently carrying out the designing, the development or the analysis of a complicated recipe-based batch process concerning medical treatment, biotechnology and agriculture. A batch process information control system (Batch/21) is provided as a system having an expanded and additional function for a batch process of InfoPlus/21, an information control system which enables the observation, management and controlling of a process. 4 figs.

  2. Systematic Methodology for Reproducible Optimizing Batch Operation

    DEFF Research Database (Denmark)

    Bonné, Dennis; Jørgensen, Sten Bay

    2006-01-01

    This contribution presents a systematic methodology for rapid acquirement of discrete-time state space model representations of batch processes based on their historical operation data. These state space models are parsimoniously parameterized as a set of local, interdependent models. The present....... This controller may also be used for Optimizing control. The modeling and control performance is demonstrated on a fed-batch protein cultivation example. The presented methodologies lend themselves directly for application as Process Analytical Technologies (PAT)....

  3. Batch Extractive Distillation with Light Entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol/water (minimum boiling azeotrope) with methanol, water/ethylene diamine (maximum boiling azeotro...

  4. Batch extractive distillation with light entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Lelkes, Zoltan; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol / water (minimum boiling azeotrope) with methanol, water / ethylene diamine (maximum boiling azeotrope...

  5. A Student-Constructed Galvanic Cell for the Measurement of Cell Potentials at Different Temperatures

    Science.gov (United States)

    Jakubowska, Anna

    2016-01-01

    A student-made galvanic cell is proposed for temperature measurements of cell potential. This cell can be easily constructed by students, the materials needed are readily available and nontoxic, and the solution applied is in an attractive color. For this cell, the potential values are excellently reproducible at each temperature, and the…

  6. A new method for the compensation of ohmic drop in galvanic cells

    NARCIS (Netherlands)

    Kooijman, D.J.; Sluyters, J.H.

    1966-01-01

    Generally the ohmic potential drop in a galvanic cell that occurs if a rectangular pulse is led through the cell, is compensated by means of a well-known bridge circuit. A better method making use of a phase reverter is described and its features are discussed. Exchange current densities up to 1200

  7. Effect of Prayer and “OM” Meditation in Enhancing Galvanic Skin Response

    Directory of Open Access Journals (Sweden)

    Ira Das

    2012-10-01

    Full Text Available The research was conducted with the purpose to study the effect of prayer and meditation on galvanic skin response (GSR. It was hypothesized that there was a significant positive effect of prayer and meditation (Om chanting on galvanic skin response (GSR. The sample consisted of 20 normal, healthy female participants through purposive sampling. The age group of the sample was 18 to 24 years (Mean= 18.7, SD= 1.55. Gender was female and minimum education was graduation. The daily practice time of prayer and meditation session was 30 minutes for one month. Pre- Post data were recorded before and after intervention of prayer and meditation session by using single group pre-post research design. Recordings of galvanic skin response (GSR were made on a computerized polygraph (Model Physiopac, PP 4, Medicaid Systems, Chandigarh, India test. The results revealed a significant increase in GSR values as an effect of prayer and meditation which suggested the psychophysiological relaxation. Practicing prayer and meditation increases the galvanic skin response and hence decreases the stress level of the individual.

  8. How are we connected? : Measuring Audience Galvanic Skin Response of Connected Performances

    NARCIS (Netherlands)

    C. Wang (Chen); X. Zhu (Xintong); E. Geelhoed; I. Biscoe; T. Röggla (Tom); P.S. Cesar Garcia (Pablo Santiago)

    2016-01-01

    textabstractAccurately measuring the audience response during a performance is a difficult task. This is particularly the case for connected performances. In this paper, we staged a connected performance in which a remote audience enjoyed the performance in real-time. Both objective (galvanic skin

  9. Spontaneous Electroless Galvanic Cell Deposition of 3D Hierarchical and Interlaced S-M-S Heterostructures.

    Science.gov (United States)

    Tan, Chuan Fu; Azmansah, Siti Aishah Bte; Zhu, Hai; Xu, Qing-Hua; Ho, Ghim Wei

    2017-01-01

    One-pot electroless galvanic cell deposition of a 3D hierarchical semiconductor-metal-semiconductor interlaced nanoarray is demonstrated. The fabricated 3D photoanode deviates from the typical planar geometry, and aims to optimize the effective surface area for light harvesting and long-range charge transfer-collection pathways.

  10. Zinc toxicity among galvanization workers in the iron and steel industry.

    Science.gov (United States)

    El Safty, Amal; El Mahgoub, Khalid; Helal, Sawsan; Abdel Maksoud, Neveen

    2008-10-01

    Galvanization is the process of coating steel or cast iron pieces with zinc, allowing complete protection against corrosion. The ultimate goal of this work was to assess the effect of occupational exposure to zinc in the galvanization process on different metals in the human body and to detect the association between zinc exposure and its effect on the respiratory system. This study was conducted in 111 subjects in one of the major companies in the iron and steel industry. There were 61 subjects (workers) who were involved in the galvanization process. Fifty adult men were chosen as a matched reference group from other departments of the company. All workers were interviewed using a special questionnaire on occupational history and chest diseases. Ventilatory functions and chest X rays were assessed in all examined workers. Also, complete blood counts were performed, and serum zinc, iron, copper, calcium, and magnesium levels were tested. This study illustrated the relation between zinc exposure in the galvanization process and high zinc levels among exposed workers, which was associated with a high prevalence rate of metal fume fever (MFF) and low blood copper and calcium levels. There was no statistically significant difference between the exposed and control groups with regards to the magnesium level. No long-term effect of metals exposure was detected on ventilatory functions or chest X rays among the exposed workers.

  11. Media Research with a Galvanic Skin Response Biosensor: Some Kids Work Up a Sweat!

    Science.gov (United States)

    Clariana, Roy B.

    This study considers the galvanic skin response (GSR) of sixth-grade students (n=20) using print, video, and microcomputer segments. Subjects received all three media treatments, in randomized order. Data for analysis consisted of standardized test scores and GSR measures; a moderate positive relationship was shown between cumulative GSR and…

  12. Investigation of the Coupling Paths of a Galvanically Isolated AC/AC Converter

    NARCIS (Netherlands)

    Roc'h, Anne; Zhao, Dongsheng; Leferink, Frank; Polinder, Henk; Ferreira, Braham

    2007-01-01

    A galvanically isolated three-phase AC/AC converter with a high-frequency AC-link has been analyzed from an EMC point of view. This is a special configuration because of a large number of switches, a high frequency transformer, and a fourwire output. The essential coupling paths are identified. Corr

  13. Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires

    Directory of Open Access Journals (Sweden)

    Marcello Gelfi

    2017-03-01

    Full Text Available This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved.

  14. Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires.

    Science.gov (United States)

    Gelfi, Marcello; Solazzi, Luigi; Poli, Sandro

    2017-03-06

    This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved.

  15. Galvanic Corrosion Behavior of Microwave Welded and Post-weld Heat-Treated Inconel-718 Joints

    Science.gov (United States)

    Bansal, Amit; Sharma, Apurbba Kumar; Kumar, Pradeep

    2017-05-01

    In the present study, corrosion behavior of microwave welded Inconel-718 at various conditions was investigated. Welding of Inconel-718 in 980 °C solution-treated condition was performed using microwave hybrid heating technique. The microwave welds were subjected to post-heat treatment for improving its microstructure and mechanical properties by solubilizing the Nb-enriched Laves phase. The microstructural features of the fabricated welds at various conditions were investigated through scanning electron microscopy. The electrochemical testing results revealed that Inconel-718 welds were galvanic corroded when they were anodically polarized in 3.5 wt.% NaCl solution at 28 °C. The difference in the corrosion potentials between the base metal (BM) and fusion zone (FZ) in an Inconel-718 weld was the main factor for galvanic corrosion. The highest corrosion was occurred in the as-welded/aged weldments, followed by 980 °C solution-treated and aged weldments, as-welded specimen, and 1080 °C solution-treated and aged (1080STA) weldments. The least galvanic corrosion was occurred in the 1080STA specimens due to almost uniform microstructure developed in the weldment after the treatment. Thus, it was possible to minimize the galvanic corrosion in the microwave welded Inconel-718 by 1080STA treatment which resulted in reducing the difference in corrosion potentials between the BM and the FZ.

  16. Electrochemical Polishing of Silverware: A Demonstration of Voltaic and Galvanic Cells

    Science.gov (United States)

    Ivey, Michelle M.; Smith, Eugene T.

    2008-01-01

    In this demonstration, the students use their knowledge of electrochemistry to determine that tarnish can be removed from silverware by electrochemically converting it back to silver using items commonly available in the kitchen: aluminum foil and baking soda. In addition to using this system as an example of a galvanic cell, an electrolytic cell…

  17. Protection of Steel Corrosion in Concrete Members by the Combination of Galvanic Anode and Nitrite Penetration

    OpenAIRE

    Minobu Aoyama; Shinichi Miyazato; Mitsunori Kawamura

    2014-01-01

    Chloride induced-corrosion of steel bars in concrete can make cracks and exfoliation in near-surface regions in reinforced concrete structures. In this paper, we described the basic concept and practice of steel bars corrosion protection method by the combination of galvanic anode (zinc wire) and the penetration of nitrite ions from mortar layers containing a large amount of lithium nitrite.

  18. Tunable growth of nanodendritic silver by galvanic-cell mechanism on formed activated carbon.

    Science.gov (United States)

    Wang, Fei; Lai, Yijian; Zhao, Binyuan; Hu, Xiaobin; Zhang, Di; Hu, Keao

    2010-06-07

    Well-defined silver dendritic nanostructures have been prepared in large quantities in an ambient environment using formed activated carbon (FAC) only. A reasonable mechanism (step 1: reduction by surface reductive groups; step 2: growing in the form of a galvanic cell) is suggested.

  19. A Student-Constructed Galvanic Cell for the Measurement of Cell Potentials at Different Temperatures

    Science.gov (United States)

    Jakubowska, Anna

    2016-01-01

    A student-made galvanic cell is proposed for temperature measurements of cell potential. This cell can be easily constructed by students, the materials needed are readily available and nontoxic, and the solution applied is in an attractive color. For this cell, the potential values are excellently reproducible at each temperature, and the…

  20. Electrochemical Polishing of Silverware: A Demonstration of Voltaic and Galvanic Cells

    Science.gov (United States)

    Ivey, Michelle M.; Smith, Eugene T.

    2008-01-01

    In this demonstration, the students use their knowledge of electrochemistry to determine that tarnish can be removed from silverware by electrochemically converting it back to silver using items commonly available in the kitchen: aluminum foil and baking soda. In addition to using this system as an example of a galvanic cell, an electrolytic cell…

  1. In situ liquid cell electron microscopy of Ag-Au galvanic replacement reactions.

    Science.gov (United States)

    Sutter, Eli A; Sutter, Peter W

    2017-01-19

    Galvanic replacement reactions are important as they transform nanoparticle templates into complex porous and hollow metal or alloy nanostructures with interesting properties for a variety of applications. Real-time liquid cell electron microscopy (LCEM) observations of the transformation of solid nanoparticles into hollow shell and cage bimetallic nanostructures are challenging because the high-energy electron beam strongly affects the galvanic process via species such as aqueous electrons and hydroxyl radicals generated through the radiolysis of water in the liquid cell. As a result the galvanic reactions are modified by the introduction of additional pathways that can decouple the oxidation of the nanoparticles from the reduction of the metal ion complexes in solution. Here we demonstrate that changing the pH of the solution provides an effective approach to alter the balance of radiolysis products. In situ observations of the transformation of Ag nanocubes in Au salt containing neutral and acidic aqueous solutions demonstrate that a lowering of the pH by addition of H2SO4 significantly lessens radical-induced modifications of redox reactions by avoiding the excessive reduction of metal-chloro complexes by aqueous electrons (eaq(-)) and making the process sufficiently slow to be observed. As a result, the different stages of galvanic replacement reactions on nanoparticles can be imaged in real-time by LCEM.

  2. Galvanic detection of sulfur dioxide in ambient air at trace levels by anodic oxidation

    NARCIS (Netherlands)

    Lindqvist, F.

    1978-01-01

    A continuous method for the measurement of SO2 in ambient air at trace levels is described. The principle of detection is based on the anodic oxidation of SO2 in a galvanic cell. A differential measuring technique with a cell with two anodes and one cathode is used; background and noise current are

  3. A new method for the compensation of ohmic drop in galvanic cells

    NARCIS (Netherlands)

    Kooijman, D.J.; Sluyters, J.H.

    Generally the ohmic potential drop in a galvanic cell that occurs if a rectangular pulse is led through the cell, is compensated by means of a well-known bridge circuit. A better method making use of a phase reverter is described and its features are discussed. Exchange current densities up to 1200

  4. A Review of Galvanically Isolated Impedance-Source DC–DC Converters

    DEFF Research Database (Denmark)

    Chub, Andrii; Vinnikov, Dmitri; Blaabjerg, Frede

    2016-01-01

    Impedance-source converters, an emerging technology in electric energy conversion, overcome limitations of conventional solutions by the use of specific impedance-source networks. Focus of this paper is on the topologies of galvanically isolated impedance-source dc-dc converters. These converters...... research directions in this field....

  5. Digitally Controlled Offline Converter with Galvanic Isolation Based on an 8-bit Microcontroller

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

    2007-01-01

    This paper presents an offline AC/DC converter with digital control and galvanic isolation that can be implemented using cheap commercially available components. An ATMEL ATTiny26 8-bit microcontroller is used to control the converter. The microcontroller is placed on the secondary side...

  6. Discharge of a copper-magnesium galvanic cell in the presence of a weak electromagnetic field

    Science.gov (United States)

    Kolesnikov, A. A.; Zarembo, Ya. V.; Zarembo, V. I.

    2007-07-01

    The effect of weak periodic electromagnetic pulses with a repetition rate of 250 kHz on the discharge of a copper-magnesium galvanic cell is studied experimentally. Comparative characteristics of the electrochemical process and scanning electron microscopy images of electrode reaction products are presented.

  7. Effects of titanium-dental restorative alloy galvanic couples on cultured cells.

    Science.gov (United States)

    Bumgardner, J D; Johansson, B I

    1998-01-01

    The potential exists for titanium and amalgams to become galvanically coupled in the oral cavity. While low galvanic corrosion rates have been measured in vivo for titanium-amalgam or mercury-free alloy couples, concerns exist over released corrosion products and adverse tissue responses. It was hypothesized in this study that coupling titanium to amalgams or gallium alloys increased the release of metallic corrosion products and decreased cellular activity and function. The effects of titanium coupled and uncoupled to a conventional amalgam, palladium-enriched spherical high copper amalgam, a dispersed type high copper amalgam, and a mercury-free gallium alloy were evaluated in 24-h cell culture tests. Viability, proliferation, and collagen synthesis were evaluated by the uptake of neutral red, 3H-thymidine, and immunoassay of procollagen, respectively, and compared to cells not exposed to any test material. The gallium alloy-titanium couple resulted in significant decreases in cellular viability, proliferation, and collagen synthesis as compared to the other coupled and uncoupled samples. Few differences in the cellular responses of the other coupled and uncoupled samples were observed. Atomic absorption analyses indicated increased release of metal ions from the amalgam and gallium alloy samples coupled to titanium as compared to their uncoupled condition, although the differences were not always significant. Galvanic corrosion of amalgam-titanium couples in the long term may become significant, and further research is needed. Coupling the gallium alloy to titanium may result in increased galvanic corrosion and cytotoxic responses.

  8. Cold metal transfer spot plug welding of AA6061-T6-to-galvanized steel for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Cao, R., E-mail: caorui@lut.cn; Huang, Q.; Chen, J.H., E-mail: zchen@lut.cn; Wang, Pei-Chung

    2014-02-05

    Highlights: • Two Al-to-galvanized steel spot plug welding joints were studied by CMT method. • The optimum process variables for the two joints were gotten by orthogonal test. • Connection mechanism of the two joints were discussed. -- Abstract: In this study, cold metal transfer (CMT) spot plug joining of 1 mm thick Al AA6061-T6 to 1 mm thick galvanized steel (i.e., Q235) was studied. Welding variables were optimized for a plug weld in the center of a 25 mm overlap region with aluminum 4043 wire and 100% argon shielding gas. Microstructures and elemental distributions were characterized by scanning electron microscopy with energy dispersive X-ray spectrometer. Mechanical testing of CMT spot plug welded joints was conducted. It was found that it is feasible to join Al AA6061T6-to-galvanized steel by CMT spot plug welding method. The process variables for two joints with Al AA6061T6-to-galvanized mild steel and galvanized mild steel-to-Al AA6061T6 are optimized. The strength of CMT spot welded Al AA6061T6-to-galvanized mild steel is determined primarily by the strength and area of the brazed interface. While, the strength of the galvanized mild steel-to-Al AA6061T6 joint is mainly dependent upon the area of the weld metal.

  9. Microbiologically influenced corrosion of galvanized steel by Desulfovibrio sp. and Desulfosporosinus sp. in the presence of Ag–Cu ions

    Energy Technology Data Exchange (ETDEWEB)

    Ilhan-Sungur, Esra, E-mail: esungur@istanbul.edu.tr [Istanbul University, Faculty of Science, Department of Biology, 34134 Vezneciler, Istanbul (Turkey); Unsal-Istek, Tuba [Istanbul University, Faculty of Science, Department of Biology, 34134 Vezneciler, Istanbul (Turkey); Cansever, Nurhan [Yıldız Technical University, Faculty of Chemistry-Metallurgy, Metallurgical and Materials Engineering Department, 34210 Esenler, Istanbul (Turkey)

    2015-07-15

    The effects of Ag–Cu ions on the microbiologically induced corrosion of galvanized steel in the presence of Desulfovibrio sp. and Desulfosporosinus sp. were investigated. The corrosion behavior of galvanized steel was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy. The biofilm, corrosion products and Ag–Cu ions on the surfaces were investigated by using scanning electron microscopy, energy dispersive X-ray spectrometry and elemental mapping. The biofilm layer formed by the Desulfovibrio sp. was stable covering the all surface of galvanized steel coupons, while that by Desulfosporosinus sp. was intermittent, highly porous and heterogeneous. It was found that both of the sulfate reducing bacteria species accelerated corrosion of the galvanized steel. However, it was detected that Desulfosporosinus sp. was more corrosive for galvanized steel than Desulfovibrio sp. Scanning electron microscopy images showed that Desulfovibrio sp. and Desulfosporosinus sp. in biofilm clustered into patches on the galvanized steel surface when the culture contained toxic Ag–Cu ions. The ions affected the growth of the sulfate reducing bacteria strains in different ways and hence the corrosion behaviors. It was observed that the Ag–Cu ions affected negatively growth of Desulfosporosinus sp. especially after 24 h of exposure leading to a decrease in the corrosion rate of galvanized steel. However, Desulfovibrio sp. showed more corrosive effect in the presence of the ions according to the ions-free culture. Energy dispersive X-ray spectrometry analysis showed that corrosion products on the surfaces were mainly composed of Zn, S, Na, O and P. - Highlights: • Galvanized steel was corroded by Desulfosporosinus sp. and Desulfovibrio sp. • Desulfosporosinus sp. is more corrosive than Desulfovibrio sp. • The Ag–Cu ions affected corrosion behavior of Desulfosporosinus sp. and Desulfovibrio sp. on galvanized steel.

  10. 21 CFR 211.188 - Batch production and control records.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Batch production and control records. 211.188... Reports § 211.188 Batch production and control records. Batch production and control records shall be... production and control of each batch. These records shall include: (a) An accurate reproduction of...

  11. 27 CFR 19.748 - Dump/batch records.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Dump/batch records. 19.748... OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Records and Reports Processing Account § 19.748 Dump/batch records. (a) Format of dump/batch records. Proprietor's dump/batch records shall contain,...

  12. A Batch Feeder for Inhomogeneous Bulk Materials

    Science.gov (United States)

    Vislov, I. S.; Kladiev, S. N.; Slobodyan, S. M.; Bogdan, A. M.

    2016-04-01

    The work includes the mechanical analysis of mechanical feeders and batchers that find application in various technological processes and industrial fields. Feeders are usually classified according to their design features into two groups: conveyor-type feeders and non-conveyor feeders. Batchers are used to batch solid bulk materials. Less frequently, they are used for liquids. In terms of a batching method, they are divided into volumetric and weighting batchers. Weighting batchers do not provide for sufficient batching accuracy. Automatic weighting batchers include a mass controlling sensor and systems for automatic material feed and automatic mass discharge control. In terms of operating principle, batchers are divided into gravitational batchers and batchers with forced feed of material using conveyors and pumps. Improved consumption of raw materials, decreased loss of materials, ease of use in automatic control systems of industrial facilities allows increasing the quality of technological processes and improve labor conditions. The batch feeder suggested by the authors is a volumetric batcher that has no comparable counterparts among conveyor-type feeders and allows solving the problem of targeted feeding of bulk material batches increasing reliability and hermeticity of the device.

  13. Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

    Science.gov (United States)

    Warsinger, David M; Tow, Emily W; Nayar, Kishor G; Maswadeh, Laith A; Lienhard V, John H

    2016-12-01

    As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Model Penjadwalan Batch Multi Item dengan Dependent Processing Time

    Directory of Open Access Journals (Sweden)

    Sukoyo Sukoyo

    2010-01-01

    Full Text Available This paper investigates a development of single machine batch scheduling for multi items with dependent processing time. The batch scheduling problem is to determine simultaneously number of batch (N, which item and its size allocated for each batch, and processing sequences of resulting batches. We use total actual flow time as the objective of schedule performance. The multi item batch scheduling problem could be formulated into a biner-integer nonlinear programming model because the number of batch should be in integer value, the allocation of items to resulting batch need binary values, and also there are some non-linearity on objective function and constraint due to the dependent processing time. By applying relaxation on the decision variable of number of batch (N as parameter, a heuristic procedure could be applied to find solution of the single machine batch scheduling problem for multi items.

  15. Dynamic Fractional Resource Scheduling vs. Batch Scheduling

    CERN Document Server

    Casanova, Henri; Vivien, Frédéric

    2011-01-01

    We propose a novel job scheduling approach for homogeneous cluster computing platforms. Its key feature is the use of virtual machine technology to share fractional node resources in a precise and controlled manner. Other VM-based scheduling approaches have focused primarily on technical issues or on extensions to existing batch scheduling systems, while we take a more aggressive approach and seek to find heuristics that maximize an objective metric correlated with job performance. We derive absolute performance bounds and develop algorithms for the online, non-clairvoyant version of our scheduling problem. We further evaluate these algorithms in simulation against both synthetic and real-world HPC workloads and compare our algorithms to standard batch scheduling approaches. We find that our approach improves over batch scheduling by orders of magnitude in terms of job stretch, while leading to comparable or better resource utilization. Our results demonstrate that virtualization technology coupled with light...

  16. Exploring the Transition From Batch to Online

    DEFF Research Database (Denmark)

    Jørgensen, Anker Helms

    2010-01-01

    of the truly interactive use of computers known today. The transition invoked changes in a number of areas: technological, such as hybrid forms between batch and online; organisational such as decentralization; and personal as users and developers alike had to adopt new technology, shape new organizational...... structures, and acquire new skills. This work-in-progress paper extends an earlier study of the transition from batch to online, based on oral history interviews with (ex)-employees in two large Danish Service Bureaus. The paper takes the next step by ana-lyzing a particular genre: the commercial computer...

  17. Use of ssq rotational invariant of magnetotelluric impedances for estimating informative properties for galvanic distortion

    Science.gov (United States)

    Rung-Arunwan, T.; Siripunvaraporn, W.; Utada, H.

    2017-06-01

    Several useful properties and parameters—a model of the regional mean one-dimensional (1D) conductivity profile, local and regional distortion indicators, and apparent gains—were defined in our recent paper using two rotational invariants (det: determinant and ssq: sum of squared elements) from a set of magnetotelluric (MT) data obtained by an array of observation sites. In this paper, we demonstrate their characteristics and benefits through synthetic examples using 1D and three-dimensional (3D) models. First, a model of the regional mean 1D conductivity profile is obtained using the average ssq impedance with different levels of galvanic distortion. In contrast to the Berdichevsky average using the average det impedance, the average ssq impedance is shown to yield a reliable estimate of the model of the regional mean 1D conductivity profile, even when severe galvanic distortion is contained in the data. Second, the local and regional distortion indicators were found to indicate the galvanic distortion as expressed by the splitting and shear parameters and to quantify their strengths in individual MT data and in the dataset as a whole. Third, the apparent gain was also shown to be a good approximation of the site gain, which is generally claimed to be undeterminable without external information. The model of the regional mean 1D profile could be used as an initial or a priori model in higher-dimensional inversions. The local and regional distortion indicators and apparent gains could be used to examine the existence and to guess the strength of the galvanic distortion. Although these conclusions were derived from synthetic tests using the Groom-Bailey distortion model, additional tests with different distortion models indicated that these conclusions are not strongly dependent on the choice of distortion model. These galvanic-distortion-related parameters would also assist in judging if a proper treatment is needed for the galvanic distortion when an MT

  18. Novel Galvanic Nanostructures of Ag and Pd for Efficient Laser Desorption/Ionization of Low Molecular Weight Compounds

    Science.gov (United States)

    Silina, Yuliya E.; Meier, Florian; Nebolsin, Valeriy A.; Koch, Marcus; Volmer, Dietrich A.

    2014-05-01

    A simple approach for synthesis of palladium and silver nanostructures with readily adjustable morphologies was developed using galvanic electrochemical deposition, for application to surface-assisted laser desorption/ionization (SALDI) of small biological molecules. A range of fatty acids, triglycerides, carbohydrates, and antibiotics were investigated to assess the performance of the new materials. Intense analyte cations were generated from the galvanic surfaces upon UV laser irradiation such as potassium adducts for a film thickness 120 nm. Possible laser desorption/ionization mechanisms of these galvanic structures are discussed. The films exhibited self-organizing abilities and adjustable morphologies by changing electrochemical parameters. They did not require any stabilizing agents and were inexpensive and very easy to produce. SALDI analysis showed that the materials were stable under ambient conditions and analytical results with excellent measurement reproducibility and detection sensitivity similar to MALDI were obtained. Finally, we applied the galvanic surfaces to fast screening of natural oils with minimum sample preparation.

  19. An On-line Galvanic Cell Generated Electrochemiluminescence and Flow Injection Determination of Calcium in Milk and Vegetable

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An on-line Ag/Al galvanic cell is investigated and employed to generateelectrochemiluminescence (ECL). The potential of the galvanic cell could be adjusted by varyingthe components of flow reagent. The cell performed perfect capability of supplying a stablepotential for ECL generation. Based on the weak ECL ofcalcein blue could be greatly sensitizedby the presence of calcium in alkaline solution, calcium contents in milk samples and in cabbagewere assayed and the results were compared with those from ICP-AES method.

  20. The Effect of a Seawater Environment on the Galvanic Corrosion Behavior of Graphite/Epoxy Composites Coupled to Metals

    Science.gov (United States)

    1992-07-01

    HY80 steel - COF (Gr/epoxy composite with one face hand sanded to initially expose a minimum 4% graphite fiber area on surface...36 4. Galvanic current data for HY80 steel - CTF (Gr/epoxy composite with two faces hand sanded to initially expose...a minimum 3% graphite fiber area on surface) ..................... ............................ ... 37 5. Galvanic current data for HY80 steel - COFM

  1. Statistical Methods for Quality Control of Steel Coils Manufacturing Process using Generalized Linear Models

    Science.gov (United States)

    García-Díaz, J. Carlos

    2009-11-01

    Fault detection and diagnosis is an important problem in process engineering. Process equipments are subject to malfunctions during operation. Galvanized steel is a value added product, furnishing effective performance by combining the corrosion resistance of zinc with the strength and formability of steel. Fault detection and diagnosis is an important problem in continuous hot dip galvanizing and the increasingly stringent quality requirements in automotive industry has also demanded ongoing efforts in process control to make the process more robust. When faults occur, they change the relationship among these observed variables. This work compares different statistical regression models proposed in the literature for estimating the quality of galvanized steel coils on the basis of short time histories. Data for 26 batches were available. Five variables were selected for monitoring the process: the steel strip velocity, four bath temperatures and bath level. The entire data consisting of 48 galvanized steel coils was divided into sets. The first training data set was 25 conforming coils and the second data set was 23 nonconforming coils. Logistic regression is a modeling tool in which the dependent variable is categorical. In most applications, the dependent variable is binary. The results show that the logistic generalized linear models do provide good estimates of quality coils and can be useful for quality control in manufacturing process.

  2. In situ liquid-cell electron microscopy of silver-palladium galvanic replacement reactions on silver nanoparticles

    Science.gov (United States)

    Sutter, E.; Jungjohann, K.; Bliznakov, S.; Courty, A.; Maisonhaute, E.; Tenney, S.; Sutter, P.

    2014-09-01

    Galvanic replacement reactions provide an elegant way of transforming solid nanoparticles into complex hollow morphologies. Conventionally, galvanic replacement is studied by stopping the reaction at different stages and characterizing the products ex situ. In situ observations by liquid-cell electron microscopy can provide insight into mechanisms, rates and possible modifications of galvanic replacement reactions in the native solution environment. Here we use liquid-cell electron microscopy to investigate galvanic replacement reactions between silver nanoparticle templates and aqueous palladium salt solutions. Our in situ observations follow the transformation of the silver nanoparticles into hollow silver-palladium nanostructures. While the silver-palladium nanocages have morphologies similar to those obtained in ex situ control experiments the reaction rates are much higher, indicating that the electron beam strongly affects the galvanic-type process in the liquid-cell. By using scavengers added to the aqueous solution we identify the role of radicals generated via radiolysis by high-energy electrons in modifying galvanic reactions.

  3. Predictability of Keeping Quality for Strawberry Batches

    NARCIS (Netherlands)

    Schouten, R.E.; Kessler, D.; Orcaray, L.; Kooten, van O.

    2002-01-01

    Postharvest life of strawberries is largely limited by Botrytis cinerea infection. It is assumed that there are two factors influencing the batch keeping quality: the Botrytis pressure and the resistance of the strawberry to infection. The latter factor will be discussed in this article. A colour

  4. Slurry Chemical Corrosion and Galvanic Corrosion during Copper Chemical Mechanical Polishing

    Science.gov (United States)

    Kondo, Seiichi; Sakuma, Noriyuki; Homma, Yoshio; Ohashi, Naofumi

    2000-11-01

    Copper (Cu) corrosion during chemical mechanical polishing (CMP) was controlled in order to improve the Cu damascene interconnect process. Slurry chemical corrosion was found to be enhanced when the slurry was diluted by deionized (DI) water during rinsing just after CMP@. Since the corrosion inhibitor, benzotriazole (BTA), reduces the Cu removal rate, adding it to the rinse solution prevents chemical corrosion more effectively than adding it to the slurry. On the other hand, galvanic corrosion occurs at the interface between Cu and the barrier metal, and it can be prevented by selecting appropriate barrier metals. Because the difference between the electrochemical potentials of Cu and the barrier metal is small in the slurry, refractory metals such as Ta, TaN, and TiN were found to be appropriate barrier metals. On the other hand, W, WN, and Ti have large potential differences, so galvanic corrosion was clearly observed when Cu/W damascene interconnects were fabricated.

  5. A Facile Fabrication of Silver-Coated Copper Nanowires by Galvanic Replacement

    Directory of Open Access Journals (Sweden)

    Xin He

    2016-01-01

    Full Text Available We demonstrated a general strategy to fabricate silver-coated copper nanowires by a galvanic replacement, which is guided by the chemical principle that metal ions (silver ions with a relatively high reduction potential can galvanically etch nanostructure made from a less metal (copper. Well-dispersed and high-yielded copper nanowires were initially synthesized and then introduced into silver-ammonia solution for the growth of silver nanocrystals on the nanowire surfaces under vigorous oscillation. The results of X-ray diffraction, scanning electron microscope, and transmission electron microscope revealed that the silver nanocrystals were uniformly distributed on the copper nanowire surfaces to form Cu-Ag heterostructures. The concentration of silver-ammonia solution and the time of replacement reaction determine the size and density of the silver nanocrystals. Our investigation might pave the way to the synthesis of other bimetallic nanostructures via a facile, fast, and economical route.

  6. Dissolved oxygen detection by galvanic displacement-induced graphene/silver nanocomposite

    Indian Academy of Sciences (India)

    Li Fu; Yuhong Zheng; Zhuxian Fu; Aiwu Wang; Wen Cai

    2015-06-01

    This paper proposed a simple, efficient and sensitive electrochemical sensor for dissolved oxygen (DO) detection based on a galvanic displacement synthesized reduced graphene oxide–silver nanoparticles (RGO/Ag) composite modified grassy carbon electrode (GCE). The synthesized RGO/Ag nanocomposite was characterized by UV–vis spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate the graphene oxide (GO) has been successfully reduced during the galvanic displacement process and the average size of Ag nanoparticle is 52 nm. The RGO/Ag nanocomposite-modified GCE showed a significant enhancement of DO detection compared with bare and RGO-modified GCEs. Moreover, the proposed DO sensor also exhibited an excellent repeatability, reproducibility and anti-interference ability

  7. Galvanic effects on electrochemical behaviors of bare surface of 304 stainless steel

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The bare surface of 304 stainless steel is produced by the fast fracture method. The influence of the surfacegalvanic cell on the electrochemical behaviors of bare surface of 304 stainless steel has been investigated in H2SO4 solutionswith different concentrations. The results show that the solution corrosivity level and the area ratio influence the surfacegalvanic effects caused by the inhomogeneity between the free-film surface of alloy and the passive surface. The surfacegalvanic effects can speed up the dissolution rate of the bare surface of the alloy and will change the electrochemical behav-ior of bare surface. With the increase of the area ratio between passive surface and fractured surface, the galvanic potentialbecomes more positive and, in the range of passive potential, both galvanic current and the peak fracture current increase

  8. Corrosion Protection of Electro-Galvanized Steel by Green Conversion Coatings

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A cerium-based chemical conversion process was studied. First, zinc coating obtained from a free-cyanide alkaline bath, with derivative of imidazol with new brightener, was investigated, zinc-plated steel specimens were treated with a solution of 50 mmol·L-1 Ce(NO3)3. The corrosion behavior of bare and treated mild galvanized steel was evaluated during exposure to 0.5 mol·L-1 NaCl for different immersion time, using Tafel polarization curves and electrochemical impedance spectroscopy (EIS) measurements. The surface morphology of the coating was studied using scanning electron microscopy (SEM). The composition and chemical percent of the coating were examined by X-ray dispersion energy (EDAX). The results of these measurements showed that the newly developed cerium-based conversion coating process was a promising candidate for replacing the conventional chromate treatments used at present for galvanized steel.

  9. A negative effect of the insoluble particles of dross on the quality of the galvanized coatings

    Science.gov (United States)

    Vourlias, George; Pistofidis, Nikolaos; Stergioudis, George; Polychroniadis, Efstathios K.

    2005-04-01

    In continuous galvanizing process several byproducts are formed. Amongst these byproducts insoluble particles composed by different compounds are grown. The most problematic seems to be a complex oxide of a ZnAl 2- xFe yO 4 stoichiometry (spinels) with variable lattice parameters, which is formed at the zinc/substrate interface. This oxide accelerates the breakdown of Fe-Al passive layer, resulting in the formation of a series of Fe-Zn intermetallic phases by an outburst growth. The samples used in this study were industrially galvanized wires and byproducts, which were studied by different methods, i.e., Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-Rays-Diffraction (XRD).

  10. Investigation of galvanic-coupled intrabody communication using the human body circuit model.

    Science.gov (United States)

    Kibret, Behailu; Seyedi, MirHojjat; Lai, Daniel T H; Faulkner, Micheal

    2014-07-01

    Intrabody Communication (IBC) is a technique that uses the human body as a transmission medium for electrical signals to connect wearable electronic sensors and devices. Understanding the human body as the transmission medium in IBC paves way for practical implementation of IBC in body sensor networks. In this study, we propose a model for galvanic coupling-type IBC based on a simplified equivalent circuit representation of the human upper arm. We propose a new way to calculate the electrode-skin contact impedance. Based on the model and human experimental results, we discuss important characteristics of galvanic coupling-type IBC, namely, the effect of tissues, anthropometry of subjects, and electrode configuration on signal propagation. We found that the dielectric properties of the muscle primarily characterize the received signal when receiver electrodes are located close to transmitter electrodes. When receiver and transmitter electrodes are far apart, the skin dielectric property affects the received signal.

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

    Directory of Open Access Journals (Sweden)

    M. Arthanareeswari

    2013-01-01

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

  12. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Blanda, Giuseppe [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Piazza, Salvatore; Sunseri, Carmelo [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Inguanta, Rosalinda, E-mail: rosalinda.inguanta@unipa.it [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO{sub 4}·H{sub 2}O; HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO{sub 3}){sub 2}·4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

  13. Greenvec Game for Skin Conductivity Level (SCL) Biofeedback Performance Simulator Using Galvanic Skin Response (GSR) Sensor

    OpenAIRE

    A. Noraziah; Muhd Azrulnizam Suna Abdullah; Nurzety Aqtar; Mohammed Adam Ibrahim Fakhreldin; Muhammad Nubli Abd Wahab

    2015-01-01

    The increasing fame of biofeedback game has brought convenience to human life. More and more people rely on biofeedback game as an alternative medical treatment to overcome their stress problems. GreenVec Biofeedback Game (GVBG) is a biofeedback game-based application that able to measure the skin conductivity of the player with an integration of Galvanic Skin Response (GSR) sensor. The measurement of the skin conductivity is crucial as an indicator for human meditation improvement in terms o...

  14. Substrate decomposition in galvanic displacement reaction: Contrast between gold and silver nanoparticle formation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Tapas; Satpati, Biswarup, E-mail: biswarup.satpati@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064 (India); Kabiraj, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi-110067 (India)

    2015-06-24

    We have investigated substrate decomposition during formation of silver and gold nanoparticles in galvanic displacement reaction on germanium surfaces. Silver and gold nanoparticles were synthesized by electroless deposition on sputter coated germanium thin film (∼ 200 nm) grown initially on silicon substrate. The nanoparticles formation and the substrate corrosion were studied using scanning transmission electron microscopy (STEM) and the energy dispersive X-ray (EDX) spectroscopy.

  15. Evaluation of Galvanized and Galvalume/Paint Duplex Coating Systems for Steel Building Panels

    Science.gov (United States)

    2002-02-01

    more than 40 years (cf. web site for the Sustainable Building Sourcebook). Some literature sources suggest that Galvalume® may outperform galvanizing...by gloss and color retention (cf. web sites for: RSI, CBS, Sustainable Building Sourcebook). Manufacturers typically offer 20- to 30-year warranties...Paint Failures by Prohesion,” Journal of Oil and Color Chemists Association, vol 62, No. 4 (1970). Web Sites Sustainable Building Sourcebook

  16. REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING

    OpenAIRE

    Mônica Marques Caetano de Lima; Luciana Cerqueira Souza Solimani; Marco Antônio Quintela

    2013-01-01

    Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat these scraps t...

  17. Twin plane decoration of silver nanorods with palladium by galvanic exchange at a controlled rate.

    Science.gov (United States)

    Sławiński, Grzegorz W; Ivanova, Olga S; Zamborini, Francis P

    2011-11-01

    Here we describe the galvanic exchange of surface-grown Ag nanorods (NRs) and nanowires (NWs) with PdCl(4)(2-) as a function of the PdCl(4)(2-) concentration. The morphology of the resulting AgPd alloy nanostructures depends on the galvanic exchange rate, which increases with increasing PdCl(4)(2-) concentration over a specific concentration range. When the concentration of PdCl(4)(2-) exceeds 7.5 × 10(-5) M (or ratio of moles of PdCl(4)(2-) in solution to moles of Ag on the surface > 542), rapid galvanic exchange results in Pd deposition over the entire Ag nanostructure in the early stages of exchange. When the concentration of PdCl(4)(2-) is in the range of 1.0 × 10(-5) to 5.0 × 10(-5) M (moles of PdCl(4)(2-) in solution to moles of Ag on the surface = 13-54), Pd deposition occurs preferentially at high energy twin plane defects in the form of well-spaced nanoparticles during the early stages of exchange. In later stages, the Pd deposits grow and coalescence into a rough shell, and etching of the Ag leads to a presumably hollow nanostructure. Composition analysis by linear sweep voltammetry as a function of time shows that the galvanic exchange rate is much slower than the diffusion-limited rate and, when correlated with UV-vis spectroscopy, shows that less than 10% Pd in the nanostructure completely dampens the Ag-localized surface plasmon band.

  18. Corrosion by galvanic coupling between amalgam and different chromium-based alloys.

    Science.gov (United States)

    Ciszewski, Aleksander; Baraniak, Marek; Urbanek-Brychczyńska, Magdalena

    2007-10-01

    In recent years there has been an increase in the use of dental casting alloys in prosthodontic treatment. Many patients have metals or alloys, as well as amalgam fillings, in their mouth, and will have them for many years. The aim of this study was to evaluate and compare, in vitro, the galvanic corrosion behavior of chromium-cobalt alloy (Remanium GM 380) and chromium-nickel alloy (Remanium CS) when bound together or coupled with silver-based amalgam (Amalcap plus). An electrochemical characterization of the alloys was performed by potentiostatic and potentiodynamic methods, i.e. the open circuit potential (OCP), the corrosion potential (E(CORR)), corrosion current density (i(CORR)) and corrosion resistance (R(P)). The electromotive force (EMF) of the bimetallic cells was also tested. Electroanalytical techniques were used to estimate the release of any respective element from the dental alloys under study into the artificial saliva solution. It was found that a bimetallic cell consisting of Remanium CS and Remanium GM 380 alloys has a very low EMF (a few mV) and is not a potential source of galvanic currents in the oral cavity. However, galvanic cells prepared from Amalcap plus and Remanium CS or Remanium GM 380 showed a much greater EMF: 104 and 109mV, respectively. This clearly indicates that in these latter cases it is possible to expect some metal ions in the saliva solution as a result of the work of galvanic currents. It was found, by adsorptive stripping voltammetry analysis, that nickel or cobalt, depending on the alloy used, appeared in the saliva solution and increased in concentration over time. The results indicate that the correct design and use of dental alloys are important when determining the appropriate treatment for a specific patient.

  19. Measurement and analysis of channel attenuation characteristics for an implantable galvanic coupling human-body communication.

    Science.gov (United States)

    Zhang, Shuang; Pun, Sio Hang; Mak, Peng Un; Qin, Yu-Ping; Liu, Yi-He; Vai, Mang I

    2016-11-14

    In this study, an experiment was designed to verify the low power consumption of galvanic coupling human-body communication. A silver electrode (silver content: 99%) is placed in a pig leg and a sine wave signal with the power of 0 dBm is input. Compared with radio frequency communication and antenna transmission communication, attenuation is reduced by approximately 10 to 15 dB, so channel characteristics are highly improved.

  20. Galvanic corrosion and cytotoxic effects of amalgam and gallium alloys coupled to titanium.

    Science.gov (United States)

    Bumgardner, J D; Johansson, B I

    1996-06-01

    The aim of this study was to examine and compare the galvanic corrosion of a conventional, a dispersed high-copper, and a palladium-enriched spherical high-copper amalgam and a gallium alloy coupled to titanium in saline and cell culture solutions, and to evaluate the effects of the couples on cultured cells. The potentials and charge transfers between amalgams and titanium were measured by electrochemical corrosion methods. Cytotoxicity of the couples, as indicated by the uptake of neutral red vital stain, was determined in 24-h direct contact human gingival fibroblast cell cultures. Results of this study indicated that before connecting the high-copper amalgams to titanium, the amalgams exhibited more positive potentials which resulted in initial negative charge transfers, i.e. corrosion of titanium. However, this initial corrosion appeared to cause titanium to passivate, and a shift in galvanic currents to positive charge transfers, i.e. corrosion of the amalgam samples. Lower galvanic currents were measured for the amalgam-titanium couples as compared to the gallium alloy-titanium couple. Coupling the conventional or the palladium-enriched high-copper amalgams to titanium did not significantly affect the uptake of neutral red as compared to cells not exposed to any test alloy. However, significant cytotoxic effects were observed when the dispersed-type high-copper amalgam and the gallium alloy were coupled to titanium. Even though the corrosion currents measured for these couples were less than gold alloys coupled to amalgam, these results suggest there is the potential for released galvanic corrosion products to become cytotoxic. These data warrant further investigations into the effects of coupling amalgam and gallium alloys to titanium in the oral environment.

  1. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M.; Fontaine, G. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Unite de Catalyse et Chimie du solide UMR 8181 Bat C3, USTL, F-59655 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France)], E-mail: Michel.Traisnel@ensc-lille.fr; Lerasle, O.; Genet, N. [TOTAL France, Centre de Recherche de Solaize, Chemin du canal, BP 22, F-69360 Solaize (France)

    2008-08-30

    The efficiency of a new triazole derivative, namely, 2-{l_brace}(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1-yl)methyl]amino{r_brace} ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  2. Galvanic Corrosion of Mg-Zr Alloy and Steel or Graphite in Mineral Binders

    Science.gov (United States)

    Lambertin, David; Rooses, Adrien; Frizon, Fabien

    The dismantling of UNGG nuclear reactor generates numerous nuclear wastes such as fuel decanning commonly composed of Mg-Zr alloy. A conditioning strategy consists in encapsulating these wastes into a hydraulic binder in a suitable state for storage. The eventual presence of steel and graphite accompanying the magnesium wastes could imply corrosion by galvanic coupling. This work is an experimental investigation of the galvanic coupling between Mg-Zr alloy and steel or graphite using ZRA electrochemical method in Portland cement or geopolymer pastes. The lowest corrosion activity of magnesium alloy while coupled to graphite or steel cathode has been observed in geopolymer pastes. Indeed, in this binder, an efficient corrosion protection of the magnesium alloy maintains the galvanic current very low during all the hardening process. In geopolymer paste, current densities of anodised Mg-Zr alloy is not dependent of the cathode/anode surface ratio in the range of 0.1 to 5 due to the dominance of the anode resistance.

  3. Eco-technological process of glass-ceramic production from galvanic sludge and aluminium slag

    Directory of Open Access Journals (Sweden)

    Stanisavljević M.

    2010-01-01

    Full Text Available Methods of purification of waste water which are most commonly used in the Republic of Serbia belong to the type of conventional systems for purification such as chemical oxidation and reduction, neutralization, sedimentation, coagulation, and flocculation. Consequently, these methods generate waste sludge which, unless adequately stabilized, represents hazardous matter. The aluminium slag generated by melting or diecasting aluminium and its alloys is also hazardous matter. In this sense, this paper establishes ecological risk of galvanic waste sludge and aluminium slag and then describes the process of stabilization of these waste materials by means of transformation into a glass-ceramic structure through sintering. The obtained product was analyzed with Fourier Transform Infrared Spectroscopy (FT-IR and X-ray diffraction (XRD. The object of the paper is the eco-technological process of producing glass-ceramics from galvanic sludge and aluminium slag. The aim of the paper is to incorporate toxic metals from galvanic sludge and aluminium slag into the glass-ceramic product, in the form of solid solutions.

  4. Galvanic Corrosion of Lead by Iron (Oxyhydr)Oxides: Potential Impacts on Drinking Water Quality.

    Science.gov (United States)

    Trueman, Benjamin F; Sweet, Gregory A; Harding, Matthew D; Estabrook, Hayden; Bishop, D Paul; Gagnon, Graham A

    2017-06-20

    Lead exposure via drinking water remains a significant public health risk; this study explored the potential effects of upstream iron corrosion on lead mobility in water distribution systems. Specifically, galvanic corrosion of lead by iron (oxyhydr)oxides was investigated. Coupling an iron mineral cathode with metallic lead in a galvanic cell increased lead release by 531 μg L(-1) on average-a 9-fold increase over uniform corrosion in the absence of iron. Cathodes were composed of spark plasma sintered Fe3O4 or α-Fe2O3 or field-extracted Fe3O4 and α-FeOOH. Orthophosphate immobilized oxidized lead as insoluble hydroxypyromorphite, while humic acid enhanced lead mobility. Addition of a humic isolate increased lead release due to uniform corrosion by 81 μg L(-1) and-upon coupling lead to a mineral cathode-release due to galvanic corrosion by 990 μg L(-1). Elevated lead in the presence of humic acid appeared to be driven by complexation, with (208)Pb and UV254 size-exclusion chromatograms exhibiting strong correlation under these conditions (R(2)average = 0.87). A significant iron corrosion effect was consistent with field data: lead levels after lead service line replacement were greater by factors of 2.3-4.7 at sites supplied by unlined cast iron distribution mains compared with the alternative, lined ductile iron.

  5. Evaluation of the corrosion resistance of the galvanized SS400 steel in NaCl solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seung Mo; Jang, Chang Heui; Kim, In Sup [KAIST, Taejon (Korea, Republic of); Lee, Kyung Ho; Choi, Byung Il [Korea Hydro and Nuclear Power Co., Taejon (Korea, Republic of)

    2006-07-01

    A typical CANDU plant generates about 5,000 spent fuel bundles annually, which are stored in a spent fuel pool. Because the storage capacity of a spent pool is 10 years of spent fuel bundles, the Silo type storage modules are used to store the extra fuel bundles. In a multi-unit site like Wolsong, the extra space needed for the Silo type storage modules are ever increasing with the operating years. Therefore a more space effective storage system is necessary to accommodate all the extra spent fuels from the four CANDU units at site. A new dry storage system, MACSTOR/KN-400 (M/KN- 400) that is based upon MACSTOR design concept was developed. M/KN-400 will be built at the seaside in Wolsong site and galvanized carbon steel will be used for storage cylinder material to protect from the corrosion. Generally, galvanized carbon steels, in which the Zn layer on the surface acts as a sacrificial anode, are known to have good corrosion resistance in the atmospheric or aqueous conditions. However, in the brine condition containing chloride ions or steam environment, the Zn layer can be damaged. Therefore, considering the seaside atmosphere in which the storage system are located, the integrity of the storage cylinder is likely to be affected by the corrosion caused by the salt included in the atmosphere. In this study, electrochemical corrosion tests were performed on the galvanized carbon steels to estimate the corrosion resistance of the storage cylinder.

  6. Identification of a Critical Intermediate in Galvanic Exchange Reactions by Single-Nanoparticle Resolved Kinetics

    Science.gov (United States)

    Smith, Jeremy George; Jain, Prashant

    2014-06-01

    The realization of common materials transformations in nanocrystalline systems is fostering the development of novel nanostructures and allowing a deep look into the atomistic mechanisms involved. Galvanic corrosion is one such transformation. We studied galvanic replacement within individual metal nanoparticles by using plasmonic spectroscopy. This proved to be a powerful approach to studying materials transformations in the absence of ensemble averaging. Individual nanoscale units act as domains that can be interrogated optically in isolation, whereas the averaging of all such domains provides a bulk reaction trajectory. Single-nanoparticle reaction trajectories showed that a Ag nanoparticle exposed to Au3+ makes an abrupt transition into a nanocage structure. The transition is limited by a critical structural event, which we identified by electron microscopy to comprise the formation of a nanosized void, similar to the pitting process commonly observed in the corrosion of metals. Trajectories also revealed a surprisingly strong nonlinearity of the reaction kinetics, which we explain by a model involving the critical coalescence of vacancies into a growing void. The critical void size for galvanic exchange to spontaneously proceed was found to be 20 atomic vacancies. In the future we hope to extend this approach to examine a wide variety of materials transformations and chemical reactions.

  7. Effect of Human Movement on Galvanic Intra-Body Communication during Single Gait Cycle

    Science.gov (United States)

    Ibrahim, I. W.; Razak, A. H. A.; Ahmad, A.; Salleh, M. K. M.

    2015-11-01

    Intra-body communication (IBC) is a communication system that uses human body as a signal transmission medium. From previous research, two coupling methods of IBC were concluded which are capacitive coupling and galvanic coupling. This paper investigates the effect of human movement on IBC using the galvanic coupling method. Because the human movement is control by the limb joint, the knee flexion angle during gait cycle was used to examine the influence of human movement on galvanic coupling IBC. The gait cycle is a cycle of people walking that start from one foot touch the ground till that foot touch the ground again. Frequency range from 300 kHz to 200MHz was swept in order to investigate the signal transmission loss and the result was focused on operating frequency 70MHz to 90MHz. Results show that the transmission loss varies when the knee flexion angle increased. The highest loss of signal at frequency range between 70MHz to 90 MHz was 69dB when the knee flexion angle is 50° and the minimum loss was 51dB during the flexion angle is 5°.

  8. In situ removal of copper from sediments by a galvanic cell.

    Science.gov (United States)

    Yuan, Songhu; Wu, Chan; Wan, Jinzhong; Lu, Xiaohua

    2009-01-01

    This study dealt with in situ removal of copper from sediments through an electrokinetic (EK) process driven by a galvanic cell. Iron (Fe) and carbon (C) were placed separately and connected with a conductive wire. Polluted sediments were put between them and water was filled above the sediments. The galvanic cell was thus formed due to the different electrode potentials of Fe and C. The cell could remove the pollutants in the sediments by electromigration and/or electroosmosis. Results showed that a weak voltage less than 1V was formed by the galvanic cell. The voltage decreased with the increase of time. A slight increase of sediment pH from the anode (Fe) to the cathode (C) was observed. The presence of supernatant water inhibited the variation of sediment pH because H(+) and OH(-) could diffuse into the water. The removal of copper was affected by the sediment pH and the distribution of electrolyte in sediment and supernatant water. Lower pH led to higher removal efficiency. More electrolyte in the sediment and/or less electrolyte in the supernatant water favored the removal of copper. The major removal mechanism was proposed on the basis of the desorption of copper from sediment to pore solution and the subsequent electromigration of copper from the anode to the cathode. The diffusion of copper from sediment to supernatant water was negligible.

  9. Monte Carlo simulation on kinetics of batch and semi-batch free radical polymerization

    KAUST Repository

    Shao, Jing

    2015-10-27

    Based on Monte Carlo simulation technology, we proposed a hybrid routine which combines reaction mechanism together with coarse-grained molecular simulation to study the kinetics of free radical polymerization. By comparing with previous experimental and simulation studies, we showed the capability of our Monte Carlo scheme on representing polymerization kinetics in batch and semi-batch processes. Various kinetics information, such as instant monomer conversion, molecular weight, and polydispersity etc. are readily calculated from Monte Carlo simulation. The kinetic constants such as polymerization rate k p is determined in the simulation without of “steady-state” hypothesis. We explored the mechanism for the variation of polymerization kinetics those observed in previous studies, as well as polymerization-induced phase separation. Our Monte Carlo simulation scheme is versatile on studying polymerization kinetics in batch and semi-batch processes.

  10. Sojourn time distributions in a Markovian G-queue with batch arrival and batch removal

    OpenAIRE

    1999-01-01

    We consider a single server Markovian queue with two types of customers; positive and negative, where positive customers arrive in batches and arrivals of negative customers remove positive customers in batches. Only positive customers form a queue and negative customers just reduce the system congestion by removing positive ones upon their arrivals. We derive the LSTs of sojourn time distributions for a single server Markovian queue with positive customers and negative custom...

  11. Batch and fed-batch production of butyric acid by Clostridium butyricum ZJUCB

    Institute of Scientific and Technical Information of China (English)

    HE Guo-qing; KONG Qing; CHEN Qi-he; RUAN Hui

    2005-01-01

    The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value (16.74 g/L) of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that cultivation under fed-batch fermentation mode could enhance butyric acid production significantly (P<0.01) by C. butyricum ZJUCB.

  12. Batch and fed-batch fermentation of Bacillus thuringiensis using starch industry wastewater as fermentation substrate.

    Science.gov (United States)

    Vu, Khanh Dang; Tyagi, Rajeshwar Dayal; Valéro, José R; Surampalli, Rao Y

    2010-08-01

    Bacillus thuringiensis var. kurstaki biopesticide was produced in batch and fed-batch fermentation modes using starch industry wastewater as sole substrate. Fed-batch fermentation with two intermittent feeds (at 10 and 20 h) during the fermentation of 72 h gave the maximum delta-endotoxin concentration (1,672.6 mg/L) and entomotoxicity (Tx) (18.5 x 10(6) SBU/mL) in fermented broth which were significantly higher than maximum delta-endotoxin concentration (511.0 mg/L) and Tx (15.8 x 10(6) SBU/mL) obtained in batch process. However, fed-batch fermentation with three intermittent feeds (at 10, 20 and 34 h) of the fermentation resulted in the formation of asporogenous variant (Spo-) from 36 h to the end of fermentation (72 h) which resulted in a significant decrease in spore and delta-endotoxin concentration and finally the Tx value. Tx of suspended pellets (27.4 x 10(6) SBU/mL) obtained in fed-batch fermentation with two feeds was the highest value as compared to other cases.

  13. Batch process. Optimum designing and operation of a batch process; Bacchi purosesu

    Energy Technology Data Exchange (ETDEWEB)

    Hasebe, S. [Kyoto Univ. (Japan). Faculty of Engineering

    1997-09-05

    Since the control of a batch process becomes dynamic, it becomes necessary to handle the process differently from a continuous process in terms of the designing, operating and controlling of the process. This paper describes the characteristics and the problems to be solved of a batch process from three points of view, the designing, operation and controlling of the process. A major problem of a batch process is the designing difficulty. In a batch process, the amount of products capable of being manufactured per unit time by each apparatus and that by the whole plant structured by combining apparatuses are different, and therefore the time and apparatus capacity are wasted in some cases. The actual designing of a batch process involves various factors, such as the seasonal fluctuation of demand for products, the possibility of expanding the apparatuses in the future and the easiness of controlling the process, and the shipment of products during consecutive holidays and periodic maintenance, which are not included in the formulation of mathematical programming problems. Regarding the optimum operation of a batch process and the controlling of the same, descriptions of forming of a dynamic optimum operation pattern and verification of the sequence control system are given. 9 refs., 4 figs.

  14. Using Forensics to Untangle Batch Effects in TCGA Data - TCGA

    Science.gov (United States)

    Rehan Akbani, Ph.D., and colleagues at the University of Texas MD Anderson Cancer Center developed a tool called MBatch to detect, diagnose, and correct batch effects in TCGA data. Read more about batch effects in this Case Study.

  15. The influence of galvanic currents and voltage on the proliferation activity of lymphocytes and expression of cell surface molecules.

    Science.gov (United States)

    Podzimek, S; Hána, K; Miksovský, M; Pousek, L; Matucha, P; Meloun, M; Procházková, J

    2008-01-01

    Release of metal ions from dental metal fillings supported by galvanism can cause local or general pathological problems in sensitive and genetically susceptible individuals. We aimed to investigate in vitro lymphocyte responses and expression of surface molecules influenced by galvanic currents and voltage. Human peripheral blood lymphocytes were influenced by galvanic currents and voltages and lymphocyte proliferation was measured. Control samples were not exposed to the influence of galvanism. We also studied the expression of surface molecules by the FACS analysis. A 15-h and shorter influence of almost all tested currents and voltages caused a significant decrease in lymphocyte proliferation and the 15-h influence of 20 microA currents significantly increased expression of surface molecules CD 19, 11a/18, 19/69 and 19/95. An influence of 10 and 3 microA currents led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69 and 3/95 and to a significant increase in CD 19 expression. An 80 mV voltage influence led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69, 3/95, 19/69 and 19/95, and 200 and 300 mV voltages significantly decreased the expression of surface molecules CD 3, 19, 11a/18, 3/95 and 19/95 and significantly increased CD 19/69 expression. A long-lasting influence of galvanism can, in sensitive and genetically susceptible individuals, influence lymphocyte proliferation and surface molecule expression. The threshold for pathological values of 5 microA for galvanic currents and 100 mV for galvanic voltage was confirmed.

  16. Optimal operation of batch membrane processes

    CERN Document Server

    Paulen, Radoslav

    2016-01-01

    This study concentrates on a general optimization of a particular class of membrane separation processes: those involving batch diafiltration. Existing practices are explained and operational improvements based on optimal control theory are suggested. The first part of the book introduces the theory of membrane processes, optimal control and dynamic optimization. Separation problems are defined and mathematical models of batch membrane processes derived. The control theory focuses on problems of dynamic optimization from a chemical-engineering point of view. Analytical and numerical methods that can be exploited to treat problems of optimal control for membrane processes are described. The second part of the text builds on this theoretical basis to establish solutions for membrane models of increasing complexity. Each chapter starts with a derivation of optimal operation and continues with case studies exemplifying various aspects of the control problems under consideration. The authors work their way from th...

  17. BATCHING PRINCIPLE OF RATING POINT ACCRUAL

    Directory of Open Access Journals (Sweden)

    S. A. Safontsev

    2014-01-01

    Full Text Available The paper analyzes characteristics of the postindustrial educational system, including the credit competence assessment, academic loads, and module-rating discipline structure. The employers’ judgments, reflected in the survey outcomes, make it possible to single out the most significant competencies for students to master. Such findings are regarded as a foundation for developing the assignment modules, integrating the problematic, testing and projecting tasks, designed to master necessary competences; their effectiveness is estimated by using the criteria of behavioral psychology. The paper demonstrates the sequences of monitoring assessment of students’ academic achievements, and recommends the batching principle of rating point accrual, based on criterion-oriented evaluation standards, reflecting students’ competence levels. The authors identify the basic competence indicators: interest in the subject, reflections on the test results, and inner motivation for project activities. The complex of batching equations is given for developing the training cards of academic disciplines, and guaranteeing the effectiveness of education system.

  18. Batch Processing of CMOS Compatible Feedthroughs

    DEFF Research Database (Denmark)

    Rasmussen, F.E.; Heschel, M.; Hansen, Ole

    2003-01-01

    This paper presents a technique for batch fabrication of electrical feedthroughs in CMOS wafers. The presented process is designed with specific attention on industrial applicability. The electrical feedthroughs are processed entirely by low temperature, CMOS compatible processes. Hence, the proc......This paper presents a technique for batch fabrication of electrical feedthroughs in CMOS wafers. The presented process is designed with specific attention on industrial applicability. The electrical feedthroughs are processed entirely by low temperature, CMOS compatible processes. Hence....... The feedthrough technology employs a simple solution to the well-known CMOS compatibility issue of KOH by protecting the CMOS side of the wafer using sputter deposited TiW/Au. The fabricated feedthroughs exhibit excellent electrical performance having a serial resistance of 40 mOmega and a parasitic capacitance...

  19. Capacitated max -Batching with Interval Graph Compatibilities

    Science.gov (United States)

    Nonner, Tim

    We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.

  20. Isopropyl alcohol recovery by heteroazeotropic batch distillation

    OpenAIRE

    Van Baelen, Guy; Vreysen, Steven; Gerbaud, Vincent; Rodriguez-Donis, Ivonne; Geens, Jeroen; Janssens, Bart

    2010-01-01

    Solvent recovery is becoming a major issue in the pharmaceutical and specialty chemical industries. Solvent recovery by conventional batch distillation is limited by the frequent presence of azeotropes in the used solvent mixtures. Most distillation processes for the separation of azeotropic or difficult zeotropic mixtures involve the addition of an entrainer (homogeneous and heterogeneous azeotropic distillation or extractive distillation). In this study the recovery of IPA (isopropyl alc...

  1. Batch Computed Tomography Analysis of Projectiles

    Science.gov (United States)

    2016-05-01

    component densities and their relative shapes and locations in space. Currently, surrogate BS41 projectiles are manufactured for the US Army Research...single core of an Intel Xeon X5650 processor operating at 2.67 GHz. To batch process the (210) projectiles, a Matlab script was written to parallelize...understand manufacturing variability, and to obtain a subgroup of the most similar for later ballistic testing, while omitting outliers. These

  2. On-line Scheduling Of Multi-Server Batch Operations

    NARCIS (Netherlands)

    van der Zee, D.J.; van Harten, A.; Schuur, P.C.

    1999-01-01

    Batching jobs in a manufacturing system is a very common policy in most industries. Main reasons for batching are avoidance of setups and/or facilitation of material handling. Good examples of batch-wise production systems are ovens found in aircraft industry and in semiconductor manufacturing. Thes

  3. Accuracy Enhancement of Electrotechnical System for Bulk Material Batching

    Directory of Open Access Journals (Sweden)

    Bukreev Victor G.

    2014-01-01

    Full Text Available In the paper an automatic system for batching and mixing the components of combined feed is considered. A novel algorithm has been proposed for the batching error correction caused by mass of the material column dropping into the batching bin. The proposed algorithm has been validated in a simulation model and in an experimental facility.

  4. Secure Batch Verification Protocol for RSA Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    JIAZongpu; LIQingchao; LIZichen

    2005-01-01

    Harn, in 1998, proposed an efficient batch verification scheme for multiple RSA digital signatures.However, the scheme has a weakness, that is a signer can generate multiple signatures which can pass the batch verification scheme, but every one of these multiple signatures is not a valid signature. To avoid this disadvantage, we propose an improved batch verification scheme.

  5. SLUDGE BATCH 5 SIMULANT FLOWSHEET STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D; Michael Stone, M; Bradley Pickenheim, B; David Best, D; David Koopman, D

    2008-10-03

    The Defense Waste Processing Facility (DWPF) will transition from Sludge Batch 4 (SB4) processing to Sludge Batch 5 (SB5) processing in early fiscal year 2009. Tests were conducted using non-radioactive simulants of the expected SB5 composition to determine the impact of varying the acid stoichiometry during the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processes. The work was conducted to meet the Technical Task Request (TTR) HLW/DWPF/TTR-2007-0007, Rev. 1 and followed the guidelines of a Task Technical and Quality Assurance Plan (TT&QAP). The flowsheet studies are performed to evaluate the potential chemical processing issues, hydrogen generation rates, and process slurry rheological properties as a function of acid stoichiometry. Initial SB5 flowsheet studies were conducted to guide decisions during the sludge batch preparation process. These studies were conducted with the estimated SB5 composition at the time of the study. The composition has changed slightly since these studies were completed due to changes in the washing plan to prepare SB5 and the estimated SB4 heel mass. Nine DWPF process simulations were completed in 4-L laboratory-scale equipment using both a batch simulant (Tank 51 simulant after washing is complete) and a blend simulant (Tank 40 simulant after Tank 51 transfer is complete). Each simulant had a set of four SRAT and SME simulations at varying acid stoichiometry levels (115%, 130%, 145% and 160%). One additional run was made using blend simulant at 130% acid that included additions of the Actinide Removal Process (ARP) waste prior to acid addition and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) waste following SRAT dewatering. There are several parameters that are noteworthy concerning SB5 sludge: (1) This is the first batch DWPF will be processing that contains sludge that has had a significant fraction of aluminum removed through aluminum dissolution. (2) The sludge is high in mercury

  6. Method and electrochemical cell for synthesis and treatment of metal monolayer electrocatalysts metal, carbon, and oxide nanoparticles ion batch, or in continuous fashion

    Science.gov (United States)

    Adzic, Radoslav; Zhang, Junliang; Sasaki, Kotaro

    2015-04-28

    An apparatus and method for synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus comprises a sonication bath and a two-compartment chamber submerged in the sonication bath. The upper and lower compartments are separated by a microporous material surface. The upper compartment comprises a cover and a working electrode (WE) connected to a Pt foil contact, with the foil contact connected to the microporous material. The upper chamber further comprises reference counter electrodes. The lower compartment comprises an electrochemical cell containing a solution of metal ions. In one embodiment, the method for synthesis of electrocatalysts comprises introducing a plurality of particles into the apparatus and applying sonication and an electrical potential to the microporous material connected to the WE. After the non-noble metal ions are deposited onto the particles, the non-noble metal ions are displaced by noble-metal ions by galvanic displacement.

  7. Method and electrochemical cell for synthesis and treatment of metal monolayer electrocatalysts metal, carbon, and oxide nanoparticles ion batch, or in continuous fashion

    Energy Technology Data Exchange (ETDEWEB)

    Adzic, Radoslav; Zhang, Junliang; Sasaki, Kotaro

    2015-04-28

    An apparatus and method for synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus comprises a sonication bath and a two-compartment chamber submerged in the sonication bath. The upper and lower compartments are separated by a microporous material surface. The upper compartment comprises a cover and a working electrode (WE) connected to a Pt foil contact, with the foil contact connected to the microporous material. The upper chamber further comprises reference counter electrodes. The lower compartment comprises an electrochemical cell containing a solution of metal ions. In one embodiment, the method for synthesis of electrocatalysts comprises introducing a plurality of particles into the apparatus and applying sonication and an electrical potential to the microporous material connected to the WE. After the non-noble metal ions are deposited onto the particles, the non-noble metal ions are displaced by noble-metal ions by galvanic displacement.

  8. Batch Model for Batched Timestamps Data Analysis with Application to the SSA Disability Program.

    Science.gov (United States)

    Yue, Qingqi; Yuan, Ao; Che, Xuan; Huynh, Minh; Zhou, Chunxiao

    2016-08-01

    The Office of Disability Adjudication and Review (ODAR) is responsible for holding hearings, issuing decisions, and reviewing appeals as part of the Social Security Administration's disability determining process. In order to control and process cases, the ODAR has established a Case Processing and Management System (CPMS) to record management information since December 2003. The CPMS provides a detailed case status history for each case. Due to the large number of appeal requests and limited resources, the number of pending claims at ODAR was over one million cases by March 31, 2015. Our National Institutes of Health (NIH) team collaborated with SSA and developed a Case Status Change Model (CSCM) project to meet the ODAR's urgent need of reducing backlogs and improve hearings and appeals process. One of the key issues in our CSCM project is to estimate the expected service time and its variation for each case status code. The challenge is that the systems recorded job departure times may not be the true job finished times. As the CPMS timestamps data of case status codes showed apparent batch patterns, we proposed a batch model and applied the constrained least squares method to estimate the mean service times and the variances. We also proposed a batch search algorithm to determine the optimal batch partition, as no batch partition was given in the real data. Simulation studies were conducted to evaluate the performance of the proposed methods. Finally, we applied the method to analyze a real CPMS data from ODAR/SSA.

  9. Batch Model for Batched Timestamps Data Analysis with Application to the SSA Disability Program

    Science.gov (United States)

    Yue, Qingqi; Yuan, Ao; Che, Xuan; Huynh, Minh; Zhou, Chunxiao

    2016-01-01

    The Office of Disability Adjudication and Review (ODAR) is responsible for holding hearings, issuing decisions, and reviewing appeals as part of the Social Security Administration’s disability determining process. In order to control and process cases, the ODAR has established a Case Processing and Management System (CPMS) to record management information since December 2003. The CPMS provides a detailed case status history for each case. Due to the large number of appeal requests and limited resources, the number of pending claims at ODAR was over one million cases by March 31, 2015. Our National Institutes of Health (NIH) team collaborated with SSA and developed a Case Status Change Model (CSCM) project to meet the ODAR’s urgent need of reducing backlogs and improve hearings and appeals process. One of the key issues in our CSCM project is to estimate the expected service time and its variation for each case status code. The challenge is that the systems recorded job departure times may not be the true job finished times. As the CPMS timestamps data of case status codes showed apparent batch patterns, we proposed a batch model and applied the constrained least squares method to estimate the mean service times and the variances. We also proposed a batch search algorithm to determine the optimal batch partition, as no batch partition was given in the real data. Simulation studies were conducted to evaluate the performance of the proposed methods. Finally, we applied the method to analyze a real CPMS data from ODAR/SSA.

  10. BATCH-GE: Batch analysis of Next-Generation Sequencing data for genome editing assessment.

    Science.gov (United States)

    Boel, Annekatrien; Steyaert, Woutert; De Rocker, Nina; Menten, Björn; Callewaert, Bert; De Paepe, Anne; Coucke, Paul; Willaert, Andy

    2016-07-27

    Targeted mutagenesis by the CRISPR/Cas9 system is currently revolutionizing genetics. The ease of this technique has enabled genome engineering in-vitro and in a range of model organisms and has pushed experimental dimensions to unprecedented proportions. Due to its tremendous progress in terms of speed, read length, throughput and cost, Next-Generation Sequencing (NGS) has been increasingly used for the analysis of CRISPR/Cas9 genome editing experiments. However, the current tools for genome editing assessment lack flexibility and fall short in the analysis of large amounts of NGS data. Therefore, we designed BATCH-GE, an easy-to-use bioinformatics tool for batch analysis of NGS-generated genome editing data, available from https://github.com/WouterSteyaert/BATCH-GE.git. BATCH-GE detects and reports indel mutations and other precise genome editing events and calculates the corresponding mutagenesis efficiencies for a large number of samples in parallel. Furthermore, this new tool provides flexibility by allowing the user to adapt a number of input variables. The performance of BATCH-GE was evaluated in two genome editing experiments, aiming to generate knock-out and knock-in zebrafish mutants. This tool will not only contribute to the evaluation of CRISPR/Cas9-based experiments, but will be of use in any genome editing experiment and has the ability to analyze data from every organism with a sequenced genome.

  11. CONVERSION OF PINEAPPLE JUICE WASTE INTO LACTIC ACID IN BATCH AND FED – BATCH FERMENTATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Abdullah Mochamad Busairi

    2012-01-01

    Full Text Available Pineapple juice waste contains valuable components, which are mainly sucrose, glucose, and fructose. Recently, lactic acid has been considered to be an important raw material for the production of biodegradable lactide polymer. The fermentation experiments were carried out in a 3 litres fermentor (Biostat B Model under anaerobic condition with stirring speed of 50 rpm, temperature at 40oC, and pH of 6.00. Effect of feed concentration on lactic acid production, bacterial growth, substrate utilisation and productivity was studied. The results obtained from fed- batch culture fermentation showed that the maximum lactic acid productivity was 0.44 g/L.h for feed concentration of 90 g/L at 48 hours. Whereas the lactic acid productivity obtained from fed-batch culture was twice and half fold higher than that of batch culture productivity.  Buangan jus nanas mengandung komponen yang berharga terutama sukrosa, glukosa, dan fruktosa. Asam laktat adalah bahan baku yang terbaru dan penting untuk dibuat sebagai polimer laktat yang dapat terdegradasi oleh lingkungan. Percobaan dilakukan pada fermentor 3 liter (Model Biostat B di bawah kondisi anaerob dengan kecepatan pengadukan 50 rpm, temperatur 40oC, dan pH 6,00. Pengaruh konsentrasi umpan terhadap produksi asam laktat, pertumbuhan mikroba, pengggunaan substrat dan produktivitas telah dipelajari. Hasil yang didapatkan pada fermentasi dengan menggunakan sistem fed-batch menunjukkan bahwa produktivitas asam laktat maksimum adalah 0.44 g/L,jam dengan konsentrasi umpan, 90 g/L pada waktu 48 jam. Bahkan produktivitas asam laktat yang didapat pada kultur fed-batch lebih tinggi 2,5 kali dari pada proses menggunakan sistem batch

  12. Connections between morphological and mechanical evolution during galvanic corrosion of micromachined polycrystalline and monocrystalline silicon

    Science.gov (United States)

    Miller, David C.; Boyce, Brad L.; Kotula, Paul G.; Stoldt, Conrad R.

    2008-06-01

    Many microsystems fabrication technologies currently employ a metallic overlayer, such as gold, in electrical contact with silicon structural layers. During postprocessing in hydrofluoric-based acid solutions, a galvanic cell is created between the silicon and the metallic layer. Micromachined tensile specimens reveal that such etching in the presence of a galvanic cell can cause a catastrophic reduction in the tensile strength and apparent modulus of silicon. Detailed failure analysis was also used to compare fractured corroded Si to otherwise identical reference specimens via surface based (electron and scanning probe) microscopy as well as cross-section based structural- and composition-characterization techniques. For both polycrystalline and single-crystal silicon, galvanic corrosion can result in a thick corroded surface layer created via porous silicon formation, and/or generalized material removal depending on the etch chemistry and conditions. Under certain etching conditions, the porous silicon formation process results in cavity formation as well as preferential grain-boundary attack leading to intergranular fracture. The nature and severity of corrosion damage are shown to be influenced by the surface wetting characteristics of the etch chemistry, with poor wetting resulting in localized attack facilitated by the microstructure and good wetting resulting in generalized attack. The measured stiffness of the tensile specimens can be used to determine the effective modulus and porosity of the corroded surface layer. Extending beyond previous investigations, the present work examines the quantitative connection between the choice of chemical etchant, the corresponding damage morphology, and the resulting degradation in strength and apparent modulus. The present work also uniquely identifies important differences in polycrystalline and single-crystal Si based on their disparate damage evolution and related mechanical performance.

  13. Sojourn time distributions in a Markovian G-queue with batch arrival and batch removal

    Directory of Open Access Journals (Sweden)

    Yang Woo Shin

    1999-01-01

    Full Text Available We consider a single server Markovian queue with two types of customers; positive and negative, where positive customers arrive in batches and arrivals of negative customers remove positive customers in batches. Only positive customers form a queue and negative customers just reduce the system congestion by removing positive ones upon their arrivals. We derive the LSTs of sojourn time distributions for a single server Markovian queue with positive customers and negative customers by using the first passage time arguments for Markov chains.

  14. Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials.

    Science.gov (United States)

    Pruncu, C I; Azari, Z; Casavola, C; Pappalettere, C

    2015-01-01

    The behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic δ layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material.

  15. The Feasibility of Using a Galvanic Cell Array for Corrosion Detection and Solution Monitoring

    Science.gov (United States)

    Kolody, Mark; Calle, Luz-Marina; Zeitlin, Nancy P. (Technical Monitor)

    2003-01-01

    An initial investigation into the response of the individual galvanic couples was conducted using potentiodynamic polarization measurements of solutions under conditions of varying corrosivity. It is hypothesized that the differing electrodes may provide a means to further investigate the corrosive nature of the analyte through genetic algorithms and pattern recognition techniques. The robust design of the electrochemical sensor makes its utilization in space exploration particularly attractive. Since the electrodes are fired on a ceramic substrate at 900 C, they may be one of the most rugged sensors available for the anticipated usage.

  16. Tuning in caudal fastigial nucleus units during natural and galvanic labyrinth stimulation.

    Science.gov (United States)

    Schlosser, H G; Guldin, W O; Grüsser, O J

    2001-05-25

    Neurons of the caudal fastigial nucleus were investigated by means of single unit recordings. Natural vestibular stimuli were applied as well as galvanic labyrinth polarization. One-third of the neurons showed a convergence of vertical and horizontal canals. More than 80% of the neurons responded to polarization of both the ipsilateral and contralateral canals (binaural responders). Most neurons had a limited response range. Two classes of neurons could be distinguished: up to 1 Hz responders and up to 10 Hz responders. In addition a group of fastigial cells showed a tuning within a small range of frequencies (sharp-tuning responders).

  17. Modeling and Characterization of cMUT-based Devices Applied to Galvanic Isolation

    Science.gov (United States)

    Heller, Jacques; Boulmé, Audren; Alquier, Daniel; Ngo, Sophie; Perroteau, Marie; Certon, Domnique

    This paper describes a new way of using cMUT technology: galvanic isolation for power electronics. These devices work like acoustic transformers, except that piezoelectricity is replaced by cMUT technology. Primary and secondary circuits are two cMUT-based transducers respectively layered on each side of a silicon substrate, through which the ultrasonic triggering signal is transmitted. A specific model based on a commercial finite element code was implemented to simulate these devices. A particular attention was paid on the modeling of the cMUT/substrate coupling which is a key feature for the intended application. First experimental results performed for model validation are presented here and discussed.

  18. Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Knott, Arnold

    2015-01-01

    This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has...... conduction mode. The designed converter operates at a switching frequency of 35.6 MHz, which is well within the VHF range. The same converter is also implemented with PCB embedded inductors to minimize cost and the physical volume of the total converter....

  19. THERMAL FIELD MODELING IN THE MIG / MAG - CMT BRAZE-WELDING PROCESS OF GALVANIZED SHEETS

    Directory of Open Access Journals (Sweden)

    GHEORGHE SIMA

    2013-10-01

    Full Text Available This paper deals with some technical aspects of the optimization process braze-welding of galvanized steel sheet with a thickness of 0.7-1.5 mm. The braze-welding process is presented systemic, highlighting the input and output variables (of the zinc layer and intermetallic layer characteristics. It is presented the test for statistical analysis performed on a four-level factorial experiment aimed at studying the influence of the main simultaneously welding parameters of the welding technology CMT (Cold Metal Transfer: determining an optimal welding current IS, welding speed vS, boos current Ina and arc length correction factor l0.

  20. Evaluation of galvanic corrosion of a Zn alloy in alcohol fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ambrozin, Alessandra Regina Pepe; Monteiro, Marcos Roberto; Santos, Andre Oliveira; Kuri, Sebastiao Elias

    2010-11-15

    Galvanic corrosion of zamak was evaluated in alcohol fuel and in some alcoholic solutions that contained ionic impurities. Also, the effect of corrosive process on the quality parameters of ethanol was investigated. The results showed that corrosion of zamak mainly occurred in solutions with high levels of water and impurities. After the assays, the increasing of both pH and conductivity of the alcohols was observed. Therefore, the results showed that the contact between zamak and some materials must be avoided and the quality control of alcohol fuel must be assured as a way of avoiding damages on engines and storage-transportation fuels systems. (author)

  1. The radiation-induced galvanic effect at a metal-dielectric interface

    Science.gov (United States)

    Zaitsev, V. I.; Barykov, I. A.; Kartashov, A. V.; Terent'ev, O. V.; Rodionov, N. B.

    2016-11-01

    The effect observed upon interaction between the electromagnetic radiation with quantum energy of 25-1000 eV and a dielectric with metal coating is investigated. The radiation source was a megampere Z-pinch. Measurements performed on optical glass samples showed that radiation with a power of 106 W/cm2 in the electric circuit switching on the metalized dielectric induces the current. It is shown that the observed galvanic effect originates from the generation of hot electrons in the dielectric.

  2. Rare earth and silane as chromate replacers for corrosion protection on galvanized steel

    Institute of Scientific and Technical Information of China (English)

    PENG Tianlan; MAN Ruilin

    2009-01-01

    The present work aimed at using rare earth lanthanum salt and trimethoxy(viny)silance as chromate substitutes for galvanized steel passivation, in contrast to zinc coating samples treated with chromate. The corrosion resistance was assessed by electrochemical impedance spectroscopy (EIS) and neutral salt spray tests (NSS). Scanning electron microscopy (SEM) was used to characterize the sample surfaces. The organic coating adhesion on the panel was also investigated via varnishes-cross cut tests. The results indicated that rare earth and silane two-step treatment gave more effective anticorrosion performance than Cr, which also provided good paint adhesion. The coating formation mechanism was also discussed.

  3. Less-Conventional Low-Consumption Galvanic Separated MOSFET-IGBT Gate Drive Supply

    Directory of Open Access Journals (Sweden)

    Jean Marie Vianney Bikorimana

    2017-01-01

    Full Text Available A simple half-bridge, galvanic separated power supply which can be short circuit proof is proposed for gate driver local supplies. The supply is made while hacking a common mode type filter as a transformer, as the transformer shows a good insulation, it has a very low parasitic capacitance between primary and secondary coils, and it is cost-effective. Very low standby losses were observed during lab experiments. This makes it compatible with energy efficient drives and solar inverters.

  4. Controllable galvanic synthesis of triangular Ag-Pd alloy nanoframes for efficient electrocatalytic methanol oxidation.

    Science.gov (United States)

    Xu, Lin; Luo, Zhimin; Fan, Zhanxi; Yu, Sijia; Chen, Junze; Liao, Yusen; Xue, Can

    2015-06-08

    Triangular Ag-Pd alloy nanoframes were successfully synthesized through galvanic replacement by using Ag nanoprisms as sacrificial templates. The ridge thickness of the Ag-Pd alloy nanoframes could be readily tuned by adjusting the amount of the Pd source during the reaction. These obtained triangular Ag-Pd alloy nanoframes exhibit superior electrocatalytic activity for the methanol oxidation reaction as compared with the commercial Pd/C catalyst due to the alloyed Ag-Pd composition as well as the hollow-framed structures. This work would be highly impactful in the rational design of future bimetallic alloy nanostructures with high catalytic activity for fuel cell systems.

  5. Optimization of efficiency and energy density of passive micro fuel cells and galvanic hydrogen generators

    CERN Document Server

    Hahn, Robert; Krumbholz, Steffen; Reichl, Herbert

    2008-01-01

    A PEM micro fuel cell system is described which is based on self-breathing PEM micro fuel cells in the power range between 1 mW and 1W. Hydrogen is supplied with on-demand hydrogen production with help of a galvanic cell, that produces hydrogen when Zn reacts with water. The system can be used as a battery replacement for low power applications and has the potential to improve the run time of autonomous systems. The efficiency has been investigated as function of fuel cell construction and tested for several load profiles.

  6. Blood oxygen content in microliter samples using an easy-to-build galvanic oxygen cell.

    Science.gov (United States)

    Grubb, B R; Mills, C D

    1981-02-01

    We have designed a simple, inexpensive, easy-to-build and operate apparatus for measuring blood oxygen content. The galvanic oxygen cell (fuel cell) requires as little as 1 microliter of blood and has a measuring time of 1-3 min. It is well suited for measuring oxygen content in fluids low in oxygen inasmuch as the sensitivity of the instrument is variable. Either air or water (at a known temperature and oxygen tension) can be used for calibration. No significant differences in blood oxygen content measured with our cell or the Van Slyke manometric method were found.

  7. Optimization of efficiency and energy density of passive micro fuel cells and galvanic hydrogen generators

    OpenAIRE

    Hahn, Robert; Wagner,Stefan; Krumbholz, Steffen; Reichl, Herbert

    2008-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838); International audience; A PEM micro fuel cell system is described which is based on self-breathing PEM micro fuel cells in the power range between 1 mW and 1W. Hydrogen is supplied with on-demand hydrogen production with help of a galvanic cell, that produces hydrogen when Zn reacts with water. The system can be used as a battery replacement for low power applications and has the potential to improv...

  8. Effects of temperature and operation parameters on the galvanic corrosion of Cu coupled to Au in organic solderability preservatives process

    Science.gov (United States)

    Oh, SeKwon; Kim, YoungJun; Jung, KiMin; Kim, JongSoo; Shon, MinYoung; Kwon, HyukSang

    2017-03-01

    In this work, we quantitatively examined the effects of temperature and operation parameters such as anode (Cu) to cathode (Au) area ratio, stirring speed, and Cu ion concentration on the galvanic corrosion kinetics of Cu coupled to Au (icouple ( Cu-Au)) on print circuit board in organic solderability preservative (OSP) soft etching solution. With the increase of temperature, galvanic corrosion rate (icouple ( Cu-Au) was increased; however, the degree of galvanic corrosion rate (icouple ( Cu-Au) - icorr (Cu)) was decreased owing to the lower activation energy of Cu coupled to Au, than that of Cu alone. With the increase of area ratio (cathode/anode), stirring speed of the system, icouple ( Cu-Au) was increased by the increase of cathodic reaction kinetics. And icouple ( Cu-Au) was decreased by the increase of the Cu-ion concentration in the OSP soft etching solution.

  9. Effects of temperature and operation parameters on the galvanic corrosion of Cu coupled to Au in organic solderability preservatives process

    Science.gov (United States)

    Oh, SeKwon; Kim, YoungJun; Jung, KiMin; Kim, JongSoo; Shon, MinYoung; Kwon, HyukSang

    2017-02-01

    In this work, we quantitatively examined the effects of temperature and operation parameters such as anode (Cu) to cathode (Au) area ratio, stirring speed, and Cu ion concentration on the galvanic corrosion kinetics of Cu coupled to Au (icouple (Cu-Au)) on print circuit board in organic solderability preservative (OSP) soft etching solution. With the increase of temperature, galvanic corrosion rate (icouple (Cu-Au) was increased; however, the degree of galvanic corrosion rate (icouple (Cu-Au) - icorr (Cu)) was decreased owing to the lower activation energy of Cu coupled to Au, than that of Cu alone. With the increase of area ratio (cathode/anode), stirring speed of the system, icouple (Cu-Au) was increased by the increase of cathodic reaction kinetics. And icouple (Cu-Au) was decreased by the increase of the Cu-ion concentration in the OSP soft etching solution.

  10. Galvanic corrosion of rare earth modified AM50 and AZ91D magnesium alloys coupled to steel and aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohedano, M.; Arrabal, R.; Pardo, A.; Paucar, A.; Merino, M. C.; Matykina, E.; Mingo, B.; Garces, G.

    2014-04-01

    Electrochemical and gravimetric measurements were used to examine the effects of neodymium and gadolinium additions on the galvanic corrosion behaviour of AM50 and AZ91D magnesium alloys coupled to A 570 Gr 36 carbon steel and AA2011-AA6082 aluminium alloys. Rare earth modified alloys showed Al{sub 2}Nd/Al{sub 2}Gd and Al-Mn-Nd/Al-Mn-Gd intermetallics, reduced area fraction of {beta}-Mg{sub 1}7Al{sub 1}2 phase and increased corrosion resistance due to increased surface passivity and suppression of micro-galvanic couples. Neodymium and gadolinium additions improved the galvanic corrosion resistance of AM50 alloy, but were less effective in case of the AZ91D alloy. The AA6082 alloy was the most compatible material and the AA2011 alloy was the least compatible. (Author)

  11. A finite-element simulation of galvanic coupling intra-body communication based on the whole human body.

    Science.gov (United States)

    Song, Yong; Zhang, Kai; Hao, Qun; Hu, Lanxin; Wang, Jingwen; Shang, Fuzhou

    2012-10-09

    Simulation based on the finite-element (FE) method plays an important role in the investigation of intra-body communication (IBC). In this paper, a finite-element model of the whole body model used for the IBC simulation is proposed and verified, while the FE simulation of the galvanic coupling IBC with different signal transmission paths has been achieved. Firstly, a novel finite-element method for modeling the whole human body is proposed, and a FE model of the whole human body used for IBC simulation was developed. Secondly, the simulations of the galvanic coupling IBC with the different signal transmission paths were implemented. Finally, the feasibility of the proposed method was verified by using in vivo measurements within the frequency range of 10 kHz-5 MHz, whereby some important conclusions were deduced. Our results indicate that the proposed method will offer significant advantages in the investigation of the galvanic coupling intra-body communication.

  12. Transfer of Campylobacter from a Positive Batch to Broiler Carcasses of a Subsequently Slaughtered Negative Batch: A Quantitative Approach.

    Science.gov (United States)

    Seliwiorstow, Tomasz; Baré, Julie; Van Damme, Inge; Gisbert Algaba, Ignacio; Uyttendaele, Mieke; De Zutter, Lieven

    2016-06-01

    The present study was conducted to quantify Campylobacter cross-contamination from a positive batch of broiler chicken carcasses to a negative batch at selected processing steps and to evaluate the duration of this cross-contamination. During each of nine visits conducted in three broiler slaughterhouses, Campylobacter levels were determined on broiler carcasses originating from Campylobacter-negative batches processed immediately after Campylobacter-positive batches. Data were collected after four steps during the slaughter process (scalding, plucking, evisceration, and washing) at 1, 10, and 20 min after the start of the slaughter of the batches. Campylobacter levels in ceca of birds from Campylobacter-positive batches ranged from 5.62 to 9.82 log CFU/g. When the preceding positive batch was colonized at a low level, no (enumerable) carcass contamination was found in a subsequent negative batch. However, when Campylobacter levels were high in the positive batch, Campylobacter was found on carcasses of the subsequent negative batch but at levels significantly lower than those found on carcasses from the preceding positive batch. The scalding and the evisceration process contributed the least (< 1.5 log CFU/g) and the most (up to 4 log CFU/ g), respectively, to the Campylobacter transmission from a positive batch to a negative batch. Additionally, the number of Campylobacter cells transferred from positive to negative batches decreased over the first 20 min of sampling time. However, the reduction was slower than previously estimated in risk assessment studies, suggesting that pathogen transfer during crosscontamination is a complex process.

  13. Effect of Temperature on the Galvanic Corrosion of Cu-Ni Alloy/High Strength Steel in Seawater

    Directory of Open Access Journals (Sweden)

    Wang Chun Li

    2016-01-01

    Full Text Available The galvanic corrosion behavior of Cu-Ni Alloy(B10/high strength steel (921A has been studied using a zero-resistance ammeter (ZRA in seawater at different temperatures. As well as it was systemically investigated by weight loss measurements, electrochemical methods and scanning electron microscope.Results showed 921A acts as the anode and B10 act as the cathodes. The effect of temperature on the galvanic corrosion is important, the corrosion rate became higher with the temperature increased.

  14. Room temperature synthesis of crystallized luminescent SrWO 4 films by an adjustable galvanic cell method

    Science.gov (United States)

    Cui, Chunhua; Bi, Jian; Gao, Daojiang

    2008-09-01

    Highly crystallized luminescent SrWO 4 films were prepared directly on tungsten substrate in strontium hydroxide aqueous solution by a galvanic cell method without impressed current at room temperature. It is noteworthy that the driving force of galvanic cell method is adjustable by adding different concentrations of oxidant. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results reveal that the crystallized films have a scheelite-type tetragonal structure and homogeneous surface. The film showed single blue emissions at 447 nm with excitation lights of 220, 230, 250, 260 and 270 nm at room temperature, respectively.

  15. PBSNG—Batch System for Farm Architecture

    Institute of Scientific and Technical Information of China (English)

    J.Fromm; K.Genser; 等

    2001-01-01

    FBSNG [1] is a redesigned version of Farm Batch System (FBS[1]),which was developed as a batch process management system for off-line Run II data processing at FNAL.FBSNG is designed for UNIX computer farms and is capable of managing up to 1000 nodes in a single farm.FBSNG allows users to start arrays of parallel processes on one or more farm computers,It uses a simplified abstract resource counting method for load balancing between computers.The resource counting approach allows FBSNG to be a simple and flexible tool for farm resource management.FBSNG scheduler features include guaranteed and controllable” fair-share” scheduling.FBSNG is easily portable across different flavors of UNIX.The system has been successfully used at Fermilab as well as by off-site collaborators for several years on farms of different sizes and different platforms for off-line data processing,Monte-Carlo data generation and other tasks.

  16. Biological actions of silver nanoparticles embedded in titanium controlled by micro-galvanic effects.

    Science.gov (United States)

    Cao, Huiliang; Liu, Xuanyong; Meng, Fanhao; Chu, Paul K

    2011-01-01

    Titanium embedded with silver nanoparticles (Ag NPs) using a single step silver plasma immersion ion implantation (Ag-PIII) demonstrate micro-galvanic effects that give rise to both controlled antibacterial activity and excellent compatibility with osteoblasts. Scanning electron microscopy (SEM) shows that nanoparticles with average sizes of about 5 nm and 8 nm are formed homogeneously on the titanium surface after undergoing Ag-PIII for 0.5 h and 1 h, respectively. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) indicate that those nanoparticles are metallic silver produced on and underneath the titanium surface via a local nucleation process from the solid solution of α-Ti(Ag). The Ag-PIII samples inhibit the growth of both Staphylococcus aureus and Escherichia coli while enhancing proliferation of the osteoblast-like cell line MG63. Electrochemical polarization and Zeta potential measurements demonstrate that the low surface toxicity and good cytocompatibility are related to the micro-galvanic effect between the Ag NPs and titanium matrix. Our results show that the physico-chemical properties of the Ag NPs are important in the control of the cytotoxicity and this study opens a new window for the design of nanostructured surfaces on which the biological actions of the Ag NPs can be accurately tailored.

  17. Habituation to galvanic vestibular stimulation for analysis of postural control abilities in gymnasts.

    Science.gov (United States)

    Balter, Susan G T; Stokroos, Robert J; Akkermans, Ellen; Kingma, Herman

    2004-08-05

    The possible correlation between postural control abilities in gymnasts and the sensitivity for and the degree of short-term habituation to galvanic vestibular stimulation (GVS) was studied. Seven balance trained young girls (Dutch National Junior Gymnasts Championship) versus seven non-trained girls and twenty-five women underwent computer-controlled GVS using a monaural continuous 1-cosinusoidal stimulus of 0.5 Hz and 2 mA, repeated three times on each side [Balter, Stokroos, Boumans, Kingma, Acta Otolaryngol. (in press); Balter, Stokroos, Eterman, Paredis, Orbons, Kingma, Acta Otolaryngol. (in press)]. Results showed that mean total galvanic-induced body sway (GBS) gain was significantly lower in the trained and untrained girls compared to the adult women (P habituation to GVS (learning abilities), however, showed no significant differences between the three groups. We suggest that the superior balance control in professional gymnasts is primarily achieved through motor training and not by learning abilities or a higher sensitivity of the vestibular system [Neurosci. Lett. 225 (1998) 155].

  18. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel.

    Science.gov (United States)

    Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO4·H2O; HA, Ca10(PO4)6(OH)2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO3)2·4H2O and NH4H2PO4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50°C for all deposition times, while at 25°C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance.

  19. Influence of Ni-electrodeposited Pretreatment on Galvanized Coatings of Reactive Steels

    Institute of Scientific and Technical Information of China (English)

    CHE Chunshan; LU Jingtang; KONG Gang; XU Qiaoyu; SUI Runzhou

    2007-01-01

    Four types of steel sheets containing 0.04%, 0.09%, 0.14% and 0.36% Si, respectively, were electrodeposited with a nickel layer of 3 μm in thickness and then galvanized in molten Zn at 450℃ for various periods of time. The formation and growth of intermetallic compound layers on the surface of the samples were investigated by SEM and EDS. The experimental results show that the method of Ni-electrodeposited pretreatment can distinctively restrain the over-growth of the galvanized coatings of reactive steels and get eligible coatings with a proper thickness, bright appearance and strong adherence. EDS results indicate that a series of Ni-Zn intermetallic compounds γ',γ and δ2 are first formed on the surface of the samples. With a prolonged immersion time, the Г2-Fe-Zn-Ni and δ-Fe-Zn are formed accompanied by the gradual disappearance of γ',γ and δ2 layer. After a longer immersion time, the lumpy ζ- Fe-Zn occurs between δ and liquid Zn and the Г-Fe-Zn does between steel substrate and δ. Subsequently, ζ is in the form of a continuous and compact layer. The method of Ni-electrodeposited pretreatment changes the formation of Fe-Zn intermetallic compounds, which delay the growth of lumpy ζ and promote the growth of compact δ. Consequently, the abnormal growth of reactive steels is eliminated.

  20. Synthesis of Au-Ag alloy nanoparticles supported on silica gel via galvanic replacement reaction

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Liu; Aiqin Wang; Lin Li; Tao Zhang; Chung-Yuan Mou; Jyh-Fu Lee

    2013-01-01

    Synthesis of supported Au-Ag bimetallic has attracted much attention since we found for the first time that Au and Ag had synergistic effect on CO oxidation and preferential CO oxidation in rich hydrogen. In this work, the formation of Au-Ag alloy nanoparticles supported on silica gel by galvanic replacement reaction has been investigated. We applied various characterizations including X-ray diffraction (XRD), transmission electronic microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), X-ray absorption spectroscopy (XAS) to characterize the formation process of Au-Ag alloy. Although the average particle sizes of the Au-Ag alloy nanoparticles obtained by the galvanic replacement reaction are relatively large comparing with that of loading Au first, the catalytic activity of the catalyst in preferential CO oxidation is almost the same. This result manifested that the particle size effect of Au-Ag nanoparticles was not as tremendous as that of monometallic gold. The formation of Au-Ag alloy made it less sensitive to the particle size.

  1. A simple soft lithographic nanopatterning of gold on gallium arsenide via galvanic displacement.

    Science.gov (United States)

    Lim, Hyuneui; Noh, Jung-Hyun; Choi, Dae-Geun; Kim, Wan-Doo; Maboudian, Roya

    2010-08-01

    Nanoscale patterning of gold layers on GaAs substrate is demonstrated using a combination of soft lithographic molding and galvanic displacement deposition. First, an electroless deposition method has been developed to plate gold on GaAs with ease and cost-effectiveness. The electroless metallization process is performed by dipping the GaAs substrates into a gold salt solution without any reducing agents or additives. The deposition proceeds via galvanic displacement in which gold ions in the aqueous solution are reduced by electrons arising from the GaAs substrate itself. The deposition rate, surface morphology and adhesion property can be modulated by the plating parameters such as the choice of acids and the immersion time. Second, soft lithographic patterning of nanodots, nanorings, and nanolines are demonstrated on GaAs substrates with hard-polydimethylsiloxane (h-PDMS) mold and plasma etching. This method can be easily applied to the metallization and nanopatterning of gold on GaAs surfaces.

  2. Ultrasmooth gold thin films by self-limiting galvanic displacement on silicon.

    Science.gov (United States)

    Gutés, Albert; Carraro, Carlo; Maboudian, Roya

    2011-05-01

    Galvanic displacement (GD), a type of electroless deposition, has been used to obtain ultrasmooth gold thin films on silicon . The novel aspect of the method presented herein is the absence of fluoride ions in the liquid phase, and its principal advantage when compared to previous efforts is that the process is inherently self-limiting. The self-limiting factor is due to the fact that in the absence of fluorinated species, no silicon oxide is removed during the process. Thus, the maximum gold film thickness is achieved when elemental silicon is no longer available once the surface is oxidized completely during the galvanic displacement process. X-ray photoelectron spectroscopy has been used as a tool for thickness measurement, using the gold to silicon ratio as an analytical signal. Three gold plating solutions with different concentrations of KAuCl₄ (2, 0.2, and 0.02 mM) have been used to obtain information about the formation rate of the gold film. This XPS analysis demonstrates the formation of gold films to a maximum thickness of ∼3.5 Å. Atomic force microscopy is used to confirm surface smoothness, suggesting that the monolayer growth does not follow the Volmer-Weber growth mode, in contrast to the GD process from aqueous conditions with fluorinated species.

  3. Design of TRIP Steel With High Welding and Galvanizing Performance in Light of Thermodynamics and Kinetics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new type of transformation induced plasticity (TRIP) steel with not only high strength and high ductility but also superior welding and galvanizing properties was designed and developed recently. Low carbon and low silicon content were preliminarily selected with the aim of meeting the requirements of superior quality in both welding and galvanizing. Phosphorus was chosen as one of the alloying elements, because it could reduce carbon acttvity in cementite and increase the stability of austenite. In addition, the possibility of phosphorus segregating at grain boundary was also discussed by thermodynamics as well as kinetics. Phase diagram was estimated at high temperature and the composition of the steel was then selected in the hyperperitectic range to avoid problems, whichmight occur in sheet steel continuous casting. Phase diagram in the inter-critical temperature was estimated for the steel to obtain the starting temperature of fast cooling. For understanding the minimum rate of fast cooling, pearlite growth kinetics was calculated with self-developed diffusion coefficients of elements in grain boundary. Overaging temperature was determined through the calculation of T0 temperature by both equilibrium and para-equilibrium assumptions,which was different from the current determination, which is only based on an equilibrium estimation.

  4. Effect of Friction on the Drawing Process of Hot-Galvanized Sheet Steel

    Institute of Scientific and Technical Information of China (English)

    Hongying GONG; Wei ZHU; Zhiliang ZHANG; Zhenliang LOU

    2005-01-01

    A probe test method was employed to detect the friction condition of the interfaces between tools and blank. At the same time a self-developed measurement apparatus to realize the probe test method was also presented. Based on the analysis of force, a correlative friction model was also given. With the self-developed measurement apparatus,the effects of three kinds of lubricating oils which were in common use during the process of sheet steel drawing were studied. By probing the friction coefficient values of different lubricating oils during the drawing process of the hot-galvanized sheet steel (steel brand: ST07Zn), we can see that the friction caused by PK oil was the lowest, so the effect of PK oil was the best. Then PK oil was used as the base lubricating oil and some solid additive powers was added into it to make a new type lubrication (named as L oil).The result of test proved that the new lubricating oil had remarkable effect on the drawing process of hot-galvanized sheet steel.

  5. CFD study of ejector flow behavior in a blast furnace gas galvanizing plant

    Science.gov (United States)

    Besagni, Giorgio; Mereu, Riccardo; Inzoli, Fabio

    2015-02-01

    In recent years, there has been a growing interest toward Blast Furnace Gas (BFG) as a low-grade energy source for industrial furnaces. This paper considers the revamping of a galvanic plant furnace converted to BFG from natural gas. In the design of the new system, the ejector on the exhaust line is a critical component. This paper studies the flow behavior of the ejector using a Computational Fluid Dynamics (CFD) analysis. The CFD model is based on a 3D representation of the ejector, using air and exhaust gases as working fluids. This paper is divided in three parts. In the first part, the galvanic plant used as case study is presented and discussed, in the second part the CFD approach is outlined, and in the third part the CFD approach is validated using experimental data and the numerical results are presented and discussed. Different Reynolds-Averaged Navier-Stokes (RANS) turbulence models ( k-ω SST and k-ɛ Realizable) are evaluated in terms of convergence capability and accuracy in predicting the pressure drop along the ejector. Suggestions for future optimization of the system are also provided.

  6. Galvanic corrosion behaviour of HE 20 / MDN 138 & HE 20 / MDN 250 alloys in natural seawater

    Science.gov (United States)

    Subramanian, G.; Parthiban, G. T.; Muthuraman, K.; Ramakrishna rao, P.

    2016-09-01

    In view of their excellent mechanical properties, workability and heat treatment characteristics, MDN 138 & MDN 250 have been widely used in missile, rocket and aerospace industries. With light weight and high performance characteristics HE 20 aluminium alloy acts as an important material in defence and aerospace applications. The galvanic corrosion behaviour of the metal combinations HE 20 / MDN 138 and HE 20 / MDN 250, with 1:1 area ratio, has been studied in natural seawater using the open well facility of CECRI's Offshore Platform at Tuticorin for a year. The open circuit potentials of MDN 138, MDN 250 and HE 20 of the individual metal, the mixed potential and galvanic current of the couples HE 20 / MDN 138 and HE 20 / MDN 250 were periodically monitored throughout the study period. The calcareous deposits on MDN 138 and MDN 250 were analysed using XRD. The results of the study reveal that that HE 20 has offered required amount of protection to MDN 138 & MDN 250.

  7. Electrochemical, galvanic, and mechanical responses of grade 2 titanium in 6% sodium chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.F.; Briant, C.L.; Kumar, K.S. [Brown Univ., Providence, RI (United States). Div. of Engineering

    1999-02-01

    The electrochemical, galvanic, and mechanical responses of grade 2 titanium in 6% sodium chloride (NaCl) solution at different temperatures were investigated. The initial corrosion potential and cathodic reaction rate increased with decreasing pH and increasing temperature. The initial corrosion potential changed when titanium was coupled with other metals. Naval brass and alloy 600 (UNS N06600) anodically polarized titanium, while zinc and aluminum caused titanium to become a cathode. HY80 steel (UNS K31820), type 316 stainless steel ([SS] UNS S31600), and Monel K500 (UNS N05500, a copper-nickel alloy), polarized titanium anodically or cathodically depending upon temperature and pH. Hydrides formed on the titanium surface at potentials < {approximately} {minus}600 mV{sub SCE} to {minus}700 mV{sub SCE}. Zinc at all temperatures and HY80 at high temperatures caused hydride formation in titanium when coupled galvanically with titanium. Mechanical tests showed an {approx} 10% decrease in ductility under prior and dynamic hydrogen charging conditions.

  8. Comparison of Galvanic Currents Generated Between Different Combinations of Orthodontic Brackets and Archwires Using Potentiostat: An In Vitro Study.

    Science.gov (United States)

    Nayak, Rabindra S; Shafiuddin, Bareera; Pasha, Azam; Vinay, K; Narayan, Anjali; Shetty, Smitha V

    2015-07-01

    Technological advances in wire selection and bracket design have led to improved treatment efficiency and allowed longer time intervals between appliance adjustments. The wires remain in the mouth for a longer duration and are subjected to electrochemical reactions, mechanical forces of mastication and generalized wear. These cause different types of corrosion. This study was done to compare the galvanic currents generated between different combinations of brackets and archwires commonly used in orthodontic practices. The materials used for the study included different commercially available orthodontic archwires and brackets. The galvanic current generated by individual materials and different combinations of these materials was tested and compared. The orthodontic archwires used were 0.019″ × 0.025″ heat-activated nickel-titanium (3M Unitek), 0.019″ × 0.025″ beta-titanium (3M Unitek) and 0.019″ × 0.025″ stainless steel (3M Unitek). The orthodontic brackets used were 0.022″ MBT laser-cut (Victory Series, 3M Unitek) and metal-injection molded (Leone Company) maxillary central incisor brackets respectively. The ligature wire used for ligation was 0.009″ stainless steel ligature (HP Company). The galvanic current for individual archwires, brackets, and the different bracket-archwire-ligature combinations was measured by using a Potentiostat machine. The data were generated using the Linear Sweep Voltammetry and OriginPro 8.5 Graphing and Data Analysis Softwares. The study was conducted in two phases. Phase I comprised of five groups for open circuit potential (OCP) and galvanic current (I), whereas Phase II comprised of six groups for galvanic current alone. Mean, standard deviation and range were computed for the OCP and galvanic current (I) values obtained. Results were subjected to statistical analysis through ANOVA. In Phase I, higher mean OCP was recorded in stainless steel archwire, followed by beta-titanium archwire, heat-activated nickel

  9. Evaluation of interface adhesion of hot-dipped zinc coating on TRIP steel with tensile testing and finite element calculation

    NARCIS (Netherlands)

    Song, G.M.; De Hosson, J.T.M.; Sloof, W.G.; Pei, Y.T.

    In this work, a methodology for the determination of the interface adhesion strength of zinc coating on TRIP steel is present. This method consists of a conventional tensile test in combination with finite element calculation. The relation between the average interface crack length and the applied

  10. Melting Properties of Loose and Granulated Glass Batch

    Institute of Scientific and Technical Information of China (English)

    WANG Jing; DENG Zhenglu; XIE Jun; CHENG Jinshu; HAN Jianjun; ZHOU Xuedong

    2014-01-01

    The physical properties, the pre-reacting performance and melting properties of the loose glass batch and the granulated glass batch were investigated, respectively. The experimental results showed that compacted glass batch could reduce dust, use ultra-fine powder, and improve heat transfer efficiency. When loose glass batch was compressed into granular, the thermal conductivity was increased from 0.273 W/m•℃to 0.430 W/m•℃, the activation energy Ea of pre-reacting decreased from 178.77 kJ/mol to 143.30 kJ/mol. Using the pre-reacted granular glass batch can significantly reduce the melting time, increase the batch melting rate, and decrease the heat consumption of 1kg molten glass from 3591.24 to 3277.03kJ/kg.

  11. Adaptive quality prediction of batch processes based on PLS model

    Institute of Scientific and Technical Information of China (English)

    LI Chun-fu; ZHANG Jie; WANG Gui-zeng

    2006-01-01

    There are usually no on-line product quality measurements in batch and semi-batch processes,which make the process control task very difficult.In this paper,a model for predicting the end-product quality from the available on-line process variables at the early stage of a batch is developed using partial least squares (PLS)method.Furthermore,some available mid-course quality measurements are used to rectify the final prediction results.To deal with the problem that the process may change with time,recursive PLS (RPLS) algorithm is used to update the model based on the new batch data and the old model parameters after each batch.An application to a simulated batch MMA polymerization process demonstrates the effectiveness of the proposed method.

  12. TANK 50 BATCH 0 SALTSTONE FORMULATION CONFIRMATION

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C.

    2006-06-05

    Savannah River National Laboratory (SRNL) personnel were requested to confirm the Tank 50 Batch 0 grout formulation per Technical Task Request, SSF-TTR-2006-0001 (task 1 of 2) [1]. Earlier Batch 0 formulation testing used a Tank 50 sample collected in September 2005 and is described elsewhere [2]. The current testing was performed using a sample of Tank 50 waste collected in May 2006. This work was performed according to the Technical Task and Quality Assurance Plan (TT/QAP), WSRC-RP-2006-00594 [3]. The salt solution collected from Tank 50 in May 2006 contained approximately 3 weight percent more solids than the sample collected in September 2005. The insoluble solids took longer to settle in the new sample which was interpreted as indicating finer particles in the current sample. The saltstone formulation developed for the September 2005 Tank 50 Batch 0 sample was confirmed for the May 2006 sample with one minor exception. Saltstone prepared with the Tank 50 sample collected in May 2006 required 1.5 times more Daratard 17 set retarding admixture than the saltstone prepared with the September In addition, a sample prepared with lower shear mixing (stirring with a spatula) had a higher plastic viscosity (57 cP) than samples made with higher shear mixing in a blender (23cP). The static gel times of the saltstone slurries made with low shear mixing were also shorter ({approx}32 minutes) than those for comparable samples made in the blender ({approx}47 minutes). The addition of the various waste streams (ETP, HEU-HCAN, and GPE-HCAN) to Tank 50 from September 2005 to May 2006 has increased the amount of set retarder, Daratard 17, required for processing saltstone slurries through the Saltstone facility. If these streams are continued to be added to Tank 50, the quantity of admixtures required to maintain the same processing conditions for the Saltstone facility will probably change and additional testing is recommended to reconfirm the Tank 50 Saltstone formulation.

  13. Batching, Scheduling, Disjunctive graph, Local search, Simulated Annealing, Wafer fabrication

    OpenAIRE

    Yugma, Claude; Dauzere-Peres, Stephane; Artigues, Christian; Derreumaux, Alexandre; Sibille, Olivier

    2011-01-01

    Abstract This paper proposes an efficient heuristic algorithm for solving a complex batching and scheduling problem in a diffusion area of a semiconductor plant. Diffusion is frequently bottleneck in the plant and also one of the most complex areas in terms of number of machines, constraints to satisfy and the large number of lots to manage. The purpose of this study is to investigate an approach to group lots in batches and to schedule these batches on machines. The proble...

  14. ENGINEERING CONTRACT ON FY-2 BATCH 2 SATELLITES SIGNED

    Institute of Scientific and Technical Information of China (English)

    SunQing

    2004-01-01

    The signing ceremony of the Engineering Contract on FY-2 Batch 2 (FY-2 02) Satellites was held in Beijing by Commission of Science, Technology and Industry for National Defense (COSTIND) on August 31, 2004. The contract on the development and manufacture of FY-2 batch 2 satellites and the contract on the launch, test and control of FY-2 Batch 2 satellites were signed by China Meteorological Administration (CMA),

  15. Reducing variance in batch partitioning measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mariner, Paul E.

    2010-08-11

    The partitioning experiment is commonly performed with little or no attention to reducing measurement variance. Batch test procedures such as those used to measure K{sub d} values (e.g., ASTM D 4646 and EPA402 -R-99-004A) do not explain how to evaluate measurement uncertainty nor how to minimize measurement variance. In fact, ASTM D 4646 prescribes a sorbent:water ratio that prevents variance minimization. Consequently, the variance of a set of partitioning measurements can be extreme and even absurd. Such data sets, which are commonplace, hamper probabilistic modeling efforts. An error-savvy design requires adjustment of the solution:sorbent ratio so that approximately half of the sorbate partitions to the sorbent. Results of Monte Carlo simulations indicate that this simple step can markedly improve the precision and statistical characterization of partitioning uncertainty.

  16. Reactive Scheduling in Multipurpose Batch Plants

    Science.gov (United States)

    Narayani, A.; Shaik, Munawar A.

    2010-10-01

    Scheduling is an important operation in process industries for improving resource utilization resulting in direct economic benefits. It has a two-fold objective of fulfilling customer orders within the specified time as well as maximizing the plant profit. Unexpected disturbances such as machine breakdown, arrival of rush orders and cancellation of orders affect the schedule of the plant. Reactive scheduling is generation of a new schedule which has minimum deviation from the original schedule in spite of the occurrence of unexpected events in the plant operation. Recently, Shaik & Floudas (2009) proposed a novel unified model for short-term scheduling of multipurpose batch plants using unit-specific event-based continuous time representation. In this paper, we extend the model of Shaik & Floudas (2009) to handle reactive scheduling.

  17. A batch fabricated biomimetic dry adhesive

    Science.gov (United States)

    Northen, Michael T.; Turner, Kimberly L.

    2005-08-01

    The fine hair adhesive system found in nature is capable of reversibly adhering to just about any surface. This dry adhesive, best demonstrated in the pad of the gecko, makes use of a multilevel conformal structure to greatly increase inelastic surface contact, enhancing short range interactions and producing significant amounts of attractive forces. Recent work has attempted to reproduce and test the terminal submicrometre 'hairs' of the system. Here we report the first batch fabricated multi-scale conformal system to mimic nature's dry adhesive. The approach makes use of massively parallel MEMS processing technology to produce 20-150 µm platforms, supported by single slender pillars, and coated with ~2 µm long, ~200 nm diameter, organic looking polymer nanorods, or 'organorods'. To characterize the structures a new mesoscale nanoindenter adhesion test technique has been developed. Experiments indicate significantly improved adhesion with the multiscale system. Additional processing caused a hydrophilic to hydrophobic transformation of the surface and testing indicated further improvement in adhesion.

  18. Galvanic microparticles increase migration of human dermal fibroblasts in a wound-healing model via reactive oxygen species pathway.

    Science.gov (United States)

    Tandon, Nina; Cimetta, Elisa; Villasante, Aranzazu; Kupferstein, Nicolette; Southall, Michael D; Fassih, Ali; Xie, Junxia; Sun, Ying; Vunjak-Novakovic, Gordana

    2014-01-01

    Electrical signals have been implied in many biological mechanisms, including wound healing, which has been associated with transient electrical currents not present in intact skin. One method to generate electrical signals similar to those naturally occurring in wounds is by supplementation of galvanic particles dispersed in a cream or gel. We constructed a three-layered model of skin consisting of human dermal fibroblasts in hydrogel (mimic of dermis), a hydrogel barrier layer (mimic of epidermis) and galvanic microparticles in hydrogel (mimic of a cream containing galvanic particles applied to skin). Using this model, we investigated the effects of the properties and amounts of Cu/Zn galvanic particles on adult human dermal fibroblasts in terms of the speed of wound closing and gene expression. The collected data suggest that the effects on wound closing are due to the ROS-mediated enhancement of fibroblast migration, which is in turn mediated by the BMP/SMAD signaling pathway. These results imply that topical low-grade electric currents via microparticles could enhance wound healing.

  19. Fabrication of silicon nanowire arrays by macroscopic galvanic cell-driven metal catalyzed electroless etching in aerated HF solution.

    Science.gov (United States)

    Liu, Lin; Peng, Kui-Qing; Hu, Ya; Wu, Xiao-Ling; Lee, Shuit-Tong

    2014-03-05

    Macroscopic galvanic cell-driven metal catalyzed electroless etching (MCEE) of silicon in aqueous hydrofluoric acid (HF) solution is devised to fabricate silicon nanowire (SiNW) arrays with dissolved oxygen acting as the one and only oxidizing agent. The key aspect of this strategy is the use of a graphite or other noble metal electrode that is electrically coupled with silicon substrate.

  20. In situ 2D maps of pH shifts across brass-lead galvanic joints using microelectrodes

    Science.gov (United States)

    Ma, Xiangmeng; Lee, Woo Hyoung; Lytle, Darren A.

    2017-02-01

    Galvanic corrosion in drinking water distribution systems, such as conditions following partial lead service line replacement, can be a significant source of lead in tap water. The objective of this work was to measure the pH directly near metal surfaces using a novel experimental tool in order to understand the water chemistry at a lead-containing galvanic couple in drinking water. Specifically, pH microprofiles in the proximity of corroding metal surfaces were measured using a microelectrode to construct detailed in situ 2D spatial maps of the pH across a galvanic couple at 100 µm above the metal’s surface under flowing and stagnation conditions. The opposite pH trend was directly observed across the galvanic couple under flow and stagnation conditions. Water stagnation resulted in a pH at the anode (leaded solder) of 1.5 pH units lower than the bulk water pH (9.0) and as much as 2.5 pH units lower than the cathode (brass). These conditions can enhance lead release at the anode, which reflects different anodic-cathodic relationships of coupled metals primarily controlled by water flow. Most importantly, this work has demonstrated the ability to make real pH measurement at the surface of corroding metals using a novel microelectrode approach.

  1. Synthesis of Hollow Gold-Silver Alloyed Nanoparticles: A "Galvanic Replacement" Experiment for Chemistry and Engineering Students

    Science.gov (United States)

    Jenkins, Samir V.; Gohman, Taylor D.; Miller, Emily K.; Chen, Jingyi

    2015-01-01

    The rapid academic and industrial development of nanotechnology has led to its implementation in laboratory teaching for undergraduate-level chemistry and engineering students. This laboratory experiment introduces the galvanic replacement reaction for synthesis of hollow metal nanoparticles and investigates the optical properties of these…

  2. Galvanically Isolated Quasi-Z-Source DC–DC Converter With a Novel ZVS and ZCS Technique

    DEFF Research Database (Denmark)

    Husev, Oleksandr; Liivik, Liisa; Blaabjerg, Frede;

    2015-01-01

    This paper focuses on the galvanically isolated quasi-Z-source dc-dc converter with a novel zero voltage and zero current switching technique. The unique feature of the impedance network lies in combining the buck-boost operation capability with the short- and open-circuit immunity of transistors...

  3. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D., E-mail: david.chartier@cea.fr [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Muzeau, B. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Stefan, L. [AREVA NC/D& S - France/Technical Department, 1 place Jean Millier 92084 Paris La Défense (France); Sanchez-Canet, J. [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Monguillon, C. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2017-03-15

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  4. Synthesis of Hollow Gold-Silver Alloyed Nanoparticles: A "Galvanic Replacement" Experiment for Chemistry and Engineering Students

    Science.gov (United States)

    Jenkins, Samir V.; Gohman, Taylor D.; Miller, Emily K.; Chen, Jingyi

    2015-01-01

    The rapid academic and industrial development of nanotechnology has led to its implementation in laboratory teaching for undergraduate-level chemistry and engineering students. This laboratory experiment introduces the galvanic replacement reaction for synthesis of hollow metal nanoparticles and investigates the optical properties of these…

  5. On second order effects in a galvanic cell : Part I. Polarization by a sine wave modulated high frequency current

    NARCIS (Netherlands)

    Pol, F. van der; Sluyters-Rehbach, M.; Sluyters, J.H.

    1975-01-01

    A theoretical study is presented concerning the application of a high-frequency alternating current, amplitude modulated by a low-frequency sine wave, to a galvanic cell. Based on the correlation with the faradaic rectification technique, expressions are given for the low-frequency demodulation

  6. Voltage of a solid electrolyte galvanic cell in terms of the activity of the mobile species of the electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Naefe, H. [Max-Planck-Institut fuer Metallforschung, Pulvermetallurgisches Laboratorium, Heisenbergstrasse 3, 70569 Stuttgart (Germany)

    2007-09-15

    The voltage of a solid electrolyte galvanic cell is not related to the activity of the mobile ions in the electrolyte which is why this activity is not a measurable quantity. Any different view contradicts fundamental relationships inherent in solid state electrochemistry. (author)

  7. A Novel Field-Circuit FEM Modeling and Channel Gain Estimation for Galvanic Coupling Real IBC Measurements

    Directory of Open Access Journals (Sweden)

    Yue-Ming Gao

    2016-04-01

    Full Text Available Existing research on human channel modeling of galvanic coupling intra-body communication (IBC is primarily focused on the human body itself. Although galvanic coupling IBC is less disturbed by external influences during signal transmission, there are inevitable factors in real measurement scenarios such as the parasitic impedance of electrodes, impedance matching of the transceiver, etc. which might lead to deviations between the human model and the in vivo measurements. This paper proposes a field-circuit finite element method (FEM model of galvanic coupling IBC in a real measurement environment to estimate the human channel gain. First an anisotropic concentric cylinder model of the electric field intra-body communication for human limbs was developed based on the galvanic method. Then the electric field model was combined with several impedance elements, which were equivalent in terms of parasitic impedance of the electrodes, input and output impedance of the transceiver, establishing a field-circuit FEM model. The results indicated that a circuit module equivalent to external factors can be added to the field-circuit model, which makes this model more complete, and the estimations based on the proposed field-circuit are in better agreement with the corresponding measurement results.

  8. A Novel Field-Circuit FEM Modeling and Channel Gain Estimation for Galvanic Coupling Real IBC Measurements.

    Science.gov (United States)

    Gao, Yue-Ming; Wu, Zhu-Mei; Pun, Sio-Hang; Mak, Peng-Un; Vai, Mang-I; Du, Min

    2016-04-02

    Existing research on human channel modeling of galvanic coupling intra-body communication (IBC) is primarily focused on the human body itself. Although galvanic coupling IBC is less disturbed by external influences during signal transmission, there are inevitable factors in real measurement scenarios such as the parasitic impedance of electrodes, impedance matching of the transceiver, etc. which might lead to deviations between the human model and the in vivo measurements. This paper proposes a field-circuit finite element method (FEM) model of galvanic coupling IBC in a real measurement environment to estimate the human channel gain. First an anisotropic concentric cylinder model of the electric field intra-body communication for human limbs was developed based on the galvanic method. Then the electric field model was combined with several impedance elements, which were equivalent in terms of parasitic impedance of the electrodes, input and output impedance of the transceiver, establishing a field-circuit FEM model. The results indicated that a circuit module equivalent to external factors can be added to the field-circuit model, which makes this model more complete, and the estimations based on the proposed field-circuit are in better agreement with the corresponding measurement results.

  9. Galvanic microparticles increase migration of human dermal fibroblasts in a wound-healing model via reactive oxygen species pathway

    Science.gov (United States)

    Tandon, Nina; Cimetta, Elisa; Villasante, Aranzazu; Kupferstein, Nicolette; Southall, Michael D.; Fassih, Ali; Xie, Junxia; Sun, Ying; Vunjak-Novakovic, Gordana

    2015-01-01

    Electrical signals have been implied in many biological mechanisms, including wound healing, which has been associated with transient electrical currents not present in intact skin. One method to generate electrical signals similar to those naturally occurring in wounds is by supplementation of galvanic particles dispersed in a cream or gel. We constructed a three-layered model of skin consisting of human dermal fibroblasts in hydrogel (mimic of dermis), a hydrogel barrier layer (mimic of epidermis) and galvanic microparticles in hydrogel (mimic of a cream containing galvanic particles applied to skin). Using this model, we investigated the effects of the properties and amounts of Cu/Zn galvanic particles on adult human dermal fibroblasts in terms of the speed of wound closing and gene expression. The collected data suggest that the effects on wound closing are due to the ROS-mediated enhancement of fibroblast migration, which is in turn mediated by the BMP/SMAD signaling pathway. These results imply that topical low-grade electric currents via microparticles could enhance wound healing. PMID:24113575

  10. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy study of the corrosion behaviour of galvanized steel and electroplating steel

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M., E-mail: mlebrini@yahoo.fr [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Unite de Catalyse et Chimie du solide UMR 8181 Bat C3, USTL, F-59655, Villeneuve d' Ascq Cedex (France); Fontaine, G. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Lerasle, O.; Genet, N. [TOTAL France, Centre de Recherche de Solaize, Chemin du canal, BP 22, F-69360 Solaize (France)

    2011-02-01

    The efficiency of a formula containing 2-{l_brace}(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1-yl)methyl] amino{r_brace}ethanol (tolyltriazole) and decanoic acid as corrosion inhibitor for galvanized steel and electroplating steel in aqueous solution have been determined by electrochemical impedance spectroscopy (EIS) techniques. The experimental data obtained from this method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour in the presence of different concentration of decanoic acid (DA) in the formula was also investigated by EIS. Results obtained reveal that, the formula is a good inhibitor for galvanized steel and electroplating steel in aqueous solution, the better performance was obtained in the case of galvanized steel. The ability of the inhibitor to be adsorbed on the surface was dependent on the nature of metal. X-ray photoelectron spectroscopy surface analysis with inhibitor shows that it's chemisorbed at the galvanized and electroplating steel/aqueous solution interface.

  11. STUDI KOMPARASI PIPA SCH 40 GALVANIZE DENGAN SCH 40 NON GALVANIZE PADA SISTEM PIPA BALLAST DIKAJI DARI SEGI TEKNIS DAN EKONOMIS

    Directory of Open Access Journals (Sweden)

    Sarjito Jokosisworo

    2012-07-01

    Full Text Available Vessel is an effective and efficient medium of sea transportation because it can transport goods in a large number. In planing and constructing the vessel, therefore, it is not only striven to be economical without decreasing its function, instruction of classification, and contruction power, but also simple to get the treatment. It will make the vessel more durable and the condition of equipment structure more stable to support the operation. One the important project and construction is to determine materials that will be used on the vessel. Pipe is a dominant component in operational system of each activator engine. Besides, it is as medium to transfer bold fluid and gas from a space to another space. Hence, it is important to protect the pipe from decreasing function which is caused by corrosion, so that damages the pipe. Considering the high vessel reparation fee, it is better to shade the pipe from the damages. The most efficient and the easiest protection and treatment to reduce corrosion in a pipe system is by using Galvanized method

  12. Statistical methods in media optimization for batch and fed-batch animal cell culture.

    Science.gov (United States)

    De Alwis, Diliny M; Dutton, Roshni L; Scharer, Jeno; Moo-Young, Murray

    2007-03-01

    Hybridoma 130-8F producing anti-F monoclonal antibodies (MAb) were grown in batch and fed-batch mode with glutamine as the limiting substrate. The initial concentration of glucose varied between 10 and 25 mM but was not growth limiting. Monoclonal antibody production was identified as being partially growth associated. Employing the cumulative cell hour concept, external metabolic flux estimates were calculated during the exponential growth phase for MAb, glucose, amino acids, ammonia and lactate. Through nutritional profiling using principal component analysis (PCA) followed by partial least squares regression (PLS), key metabolites were identified and grouped for significant positive, significant negative, low level, and negligible correlation to MAb production, cellular growth, glucose consumption, and ammonia and lactate production. Significant relationships peculiar to Hybridoma 130-8F were identified, such as demand for two normally non-essential amino acids (asparagine and aspartic acid), and the positive correlation between MAb and ammonia production.

  13. Batch process. Batch process used in a beer brewery; Biru kojo no bacchi purosesu

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, K. [Kirin Engneering Co. Ltd. (Japan)

    1997-09-05

    In a beer brewing process, there is a system in which unit operation of chemical engineering is combined with the techniques of food and fermentation engineering in order to brew beer meeting the quality concept. This paper introduces the characteristics of a batch system used in the brewing of beer and the control method for the brewing of beer. The characteristics of the batch system used in a beer brewing process are the following three. In order to minimize the quality variation ascribed to the raw materials and the process, the materials are blended in various parts of the system. In the saccharification step which determines the quality of beer, two methods, i.e. a batch method and a continuous method are used, and beer brewing companies employ a saccharification system meeting the condition for attaining a desired quality of their own products. Two mashing systems are operated at different cycles shifted by half cycle from each other, not starting both at a time, so as to level the peaks of the utilities, whereby the operation of the utility-related facility is optimized. 1 ref., 2 figs., 1 tab.

  14. Adaptive scheduling of batch servers in flow shops

    NARCIS (Netherlands)

    van der Zee, D.J.

    2002-01-01

    Batch servicing is a common way of benefiting from economies of scale in manufacturing operations. Good examples of production systems that allow for batch processing are ovens found in the aircraft industry and in semiconductor manufacturing. In this paper we study the issue of dynamic scheduling o

  15. Functional stochastic resonance in human baroreflex induced by 1/f-type noisy galvanic vestibular stimulation

    Science.gov (United States)

    Soma, Rika; Kwak, Shin; Yamamoto, Yoshiharu

    2003-05-01

    We hypothesized that 1/f noise is more beneficial than the conventional white noise in optimizing the brain's response to a weak input signal, and showed that externally added 1/f noise outperforms white noise in sensitizing human baroreflex centers in the brain. We examined the compensatory heart rate response to weak periodic signal introduced at the venous blood pressure receptor, while adding either 1/f or white noise with the same variance to the brain stem by electrically stimulating the bilateral vestibular afferents cutaneously. This stochastic galvanic vestibular stimulation, activating the vestibulo-sympathetic pathway in the brain stem, optimized covariance between weak input signals and the heart rate responses both with 1/f and white noise. Further, the optimal noise level with 1/f noise was significantly lower than that with white noise, suggesting the functional benefit of 1/f noise for the neuronal information transfer in the brain.

  16. A Stress Sensor Based on Galvanic Skin Response (GSR Controlled by ZigBee

    Directory of Open Access Journals (Sweden)

    María Viqueira Villarejo

    2012-05-01

    Full Text Available Sometimes, one needs to control different emotional situations which can lead the person suffering them to dangerous situations, in both the medium and short term. There are studies which indicate that stress increases the risk of cardiac problems. In this study we have designed and built a stress sensor based on Galvanic Skin Response (GSR, and controlled by ZigBee. In order to check the device’s performance, we have used 16 adults (eight women and eight men who completed different tests requiring a certain degree of effort, such as mathematical operations or breathing deeply. On completion, we appreciated that GSR is able to detect the different states of each user with a success rate of 76.56%. In the future, we plan to create an algorithm which is able to differentiate between each state.

  17. Mechanistic Study of Shape-Anisotropic Nanomaterials Synthesized via Spontaneous Galvanic Displacement

    Energy Technology Data Exchange (ETDEWEB)

    Strand, Matthew B.; Leong, G. Jeremy; Tassone, Christopher J.; Larsen, Brian; Neyerlin, K. C.; Gorman, Brian; Diercks, David R.; Pylypenko, Svitlana; Pivovar, Bryan; Richards, Ryan M.

    2016-11-03

    Among the broad portfolio of preparations for nanoscale materials, spontaneous galvanic displacement (SGD) is emerging as an important technology because it is capable of creating functional nanomaterials that cannot be obtained through other routes and may be used to thrift precious metals used in a broad range of applications including catalysis. With advances resulting from increased understanding of the SGD process, materials that significantly improve efficiency and potentially enable widespread adoption of next generation technologies can be synthesized. In this work, PtAg nanotubes synthesized via displacement of Ag nanowires by Pt were used as a model system to elucidate the fundamental mechanisms of SGD. Characterization by X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and atom probe tomography (APT) indicates nanotubes are formed as Ag is oxidized first from the surface and then from the center of the nanowire, with Pt deposition forming a rough, heterogeneous surface on the PtAg nanotube.

  18. A stress sensor based on Galvanic Skin Response (GSR) controlled by ZigBee.

    Science.gov (United States)

    Villarejo, María Viqueira; Zapirain, Begoña García; Zorrilla, Amaia Méndez

    2012-01-01

    Sometimes, one needs to control different emotional situations which can lead the person suffering them to dangerous situations, in both the medium and short term. There are studies which indicate that stress increases the risk of cardiac problems. In this study we have designed and built a stress sensor based on Galvanic Skin Response (GSR), and controlled by ZigBee. In order to check the device's performance, we have used 16 adults (eight women and eight men) who completed different tests requiring a certain degree of effort, such as mathematical operations or breathing deeply. On completion, we appreciated that GSR is able to detect the different states of each user with a success rate of 76.56%. In the future, we plan to create an algorithm which is able to differentiate between each state.

  19. Preparation of superhydrophobic silver nano coatings with feather-like structures by electroless galvanic deposition

    Institute of Scientific and Technical Information of China (English)

    FENG XiaoJuan; SHI YanLong; WANG YongSheng; YUE GuoRen; YANG Wu

    2013-01-01

    Superhydrophobic silver nanocoatings with feather-like morphology are fabricated on copper substrates by electroless galvanic deposition.The coating exhibit superhydrophobicity with a contact angle of 156.4° and glide angle of 4° without any further surface modification.Scanning electron microscope (SEM),X-ray diffraction (XRD) and contact angle measurements are used to investigate the morphology,crystal structure and superhydrophobicity,respectively,of the coatings.The coatings exhibit high thermal stability; their water contact angle did not change when the coatings were heated to 200℃ for 2 h.The mechanism of superhydrophobicity of the silver coating is discussed based on the work of Amirfazli,Wenzel and Cassie.

  20. Galvanic vestibular stimulation: a novel modulatory countermeasure for vestibular-associated movement disorders

    Directory of Open Access Journals (Sweden)

    Carlos V. Rizzo-Sierra

    2014-01-01

    Full Text Available Motion sickness or kinetosis is the result of the abnormal neural output originated by visual, proprioceptive and vestibular mismatch, which reverses once the dysfunctional sensory information becomes coherent. The space adaptation syndrome or space sickness relates to motion sickness; it is considered to be due to yaw, pith, and roll coordinates mismatch. Several behavioural and pharmacological measures have been proposed to control these vestibular-associated movement disorders with no success. Galvanic vestibular stimulation has the potential of up-regulating disturbed sensory-motor mismatch originated by kinetosis and space sickness by modulating the GABA-related ion channels neural transmission in the inner ear. It improves the signal-to-noise ratio of the afferent proprioceptive volleys, which would ultimately modulate the motor output restoring the disordered gait, balance and human locomotion due to kinetosis, as well as the spatial disorientation generated by gravity transition.

  1. Effective piezoelectric response of substrate-integrated ZnO nanowire array devices on galvanized steel.

    Science.gov (United States)

    Velazquez, By Jesus M; Baskaran, Sivapalan; Gaikwad, Anil V; Ngo-Duc, Tam-Triet; He, Xiangtong; Oye, Michael M; Meyyappan, M; Rout, Tapan K; Fu, John Y; Banerjee, Sarbajit

    2013-11-13

    Harvesting waste energy through electromechanical coupling in practical devices requires combining device design with the development of synthetic strategies for large-area controlled fabrication of active piezoelectric materials. Here, we show a facile route to the large-area fabrication of ZnO nanostructured arrays using commodity galvanized steel as the Zn precursor as well as the substrate. The ZnO nanowires are further integrated within a device construct and the effective piezoelectric response is deduced based on a novel experimental approach involving induction of stress in the nanowires through pressure wave propagation along with phase-selective lock-in detection of the induced current. The robust methodology for measurement of the effective piezoelectric coefficient developed here allows for interrogation of piezoelectric functionality for the entire substrate under bending-type deformation of the ZnO nanowires.

  2. GALVANIC MAGNETIC PROPERTIES OF BISMUTH THIN FILMS DOPED WITH TELLURIUM MADE BY THERMAL VACUUM EVAPORATION

    Directory of Open Access Journals (Sweden)

    V. A. Komarov

    2013-01-01

    Full Text Available The influence of n-type impurity of tellurium (concentration range from 0.005 atomic % Te to 0.15 atomic % Te on galvanic magnetic properties (resistivity, magnetic resistance and Hall constant of Bi thin films with various thicknesses was studied. The properties were measured in temperature range from 77 to 300 K. It was established that the classical size effect in the films is significant and decreases with higher concentration of Te impurity. The analysis of experimental results was carried out in approximation of the law of Jones-Schoenberg dispersion for Bi films doped with tellurium. Calculation of concentration and mobility of charge carriers in the studied films was made.

  3. Corrosion Resistance of Galvanized Steel in the Environment of a Bioreactor

    Directory of Open Access Journals (Sweden)

    Šustr Michal

    2016-06-01

    Full Text Available The article deals with monitoring the corrosion resistibility of welded materials in the anaerobic fermenter (bioreactor. The main goal of this research is to assess the change of hardness after degradation. The change of hardness occurs in the corrosion environment and it correlates with the corrosion resistibility of material. The purpose of this experiment is to recognize the possibilities of using the CMT welded materials in the defined environment. As an innovative technology the acoustic emission method is used for assessment of surface layer disruption during hardness testing. Aluminium alloy with galvanized steel (AluZinc was used as an experimental material. The basic materials were welded by the filler material AlSi3.

  4. Highly wearable galvanic skin response sensor using flexible and conductive polymer foam.

    Science.gov (United States)

    Kim, Jeehoon; Kwon, Sungjun; Seo, Sangwon; Park, Kwangsuk

    2014-01-01

    Owing to advancements in daily physiological monitoring technology, diverse healthcare applications have emerged recently. The monitoring of skin conductance responses has extensive feasibility to support healthcare applications such as detecting emotion changes. In this study, we proposed a highly wearable and reliable galvanic skin response (GSR) sensor that measures the signals from the back of the user. To enhance its wearability and usability, we employed flexible conductive foam as the sensing material and designed it to be easily attachable to (and detachable from) a wide variety of clothes. We evaluated the sensing reliability of the proposed sensor by comparing its signal with a reference GSR. The average correlation between the two signals was 0.768; this is sufficiently high to validate the feasibility of the proposed sensor for reliable GSR sensing on the back.

  5. Galvanic corrosion between dental precious alloys and magnetic stainless steels used for dental magnetic attachments.

    Science.gov (United States)

    Takahashi, Noriko; Takada, Yukyo; Okuno, Osamu

    2008-03-01

    In this study, we examined the corrosion behavior of dental precious alloys and magnetic stainless steels, namely SUS 444, SUS XM27, and SUS 447J1, used for dental magnetic attachments. Their galvanic corrosion behavior was evaluated from the viewpoint of corrosion potentials when they were in contact with each other. Rest potentials of the precious alloys were constantly higher than those of magnetic stainless steels. Since most gold alloys raised the corrosion potential more significantly than silver alloys did, silver alloys seemed to be better suited than gold alloys for combination with magnetic stainless steels. However, all corrosion potential values were sufficiently lower than the breakdown potentials of the stainless steels and existed within their passive regions. Based on the findings of this study, SUS XM27 and SUS 447J1--which exhibited higher breakdown potentials than SUS 444--emerged as the preferred choices for combination with gold alloys.

  6. Interfacial structure and joint strengthening in arc brazed galvanized steels with copper based filler

    Institute of Scientific and Technical Information of China (English)

    LI Rui-feng; YU Zhi-shui; QI Kai

    2006-01-01

    Galvanized steel sheets were joined by tungsten inert gas(TIG) and metal inert gas(MIG) brazing process using copper based filler. The results show that the joint zone hardness is higher than that of the base material or copper filler from the microhardness tests of TIG brazing specimens, and the fracture spot is at the base materials zone from the tensile tests of MIG brazing specimens. Examination using energy dispersive X-ray analysis reveals the presence of intermetallic compound Fe5Si3(Cu) in the joint. The dispersal of fine Fe5Si3(Cu) particles is the main strengthening factor for the joint. The Fe5Si3(Cu) particles are determined to arise from three sources, namely, spot micro-melt, whisker-like fragmentation and dissolve-separation actions.

  7. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    Energy Technology Data Exchange (ETDEWEB)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-03-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed.

  8. A pilot-scale trial of an improved galvanic deoxidation process for refining molten copper

    Science.gov (United States)

    Soral, P.; Pal, U.; Larson, H. R.; Schroeder, B.

    1999-04-01

    A laboratory-scale galvanic deoxidation technology developed by earlier workers has been improved, with the aim of developing a prototype pilot-scale deoxidation unit. Each deoxidation cell consists of a one end-closed yttria-stabilized zirconia (YSZ) tube coated with a Ni-YSZ cermet anode on the inner walls. The YSZ tube is immersed, with its closed end in the metallic melt, and an oxygen-chemical-potential gradient across the tube is established by passing a reducing gas through the tube. The melt is then deoxidized by short circuiting it with the anode. Through laboratory experimentation, the nature of the anode/electrolyte interface adhesion was identified to be an important factor in obtaining enhanced deoxidation kinetics. The kinetics of oxygen removal from the melt was increased by an order of magnitude with an improved anode/electrolyte interface. A pilot-scale refining unit consisting of 53 cells with the improved anode/electrolyte interface was manufactured, and a field evaluation of the galvanic deoxidation of copper was conducted. The deoxidation-process model was modified to include multiple deoxidation cells, which were required for the pilot-scale trials, and to analyze the effect of electrolyte/electrode adhesion on deoxidation kinetics. Preliminary studies on process component lifetimes were conducted by investigating the thermal cycling, corrosion behavior of the electrolyte, and stability of the cermet anode structure. Based on the results of the field trial and the analyses of the process component lifetime, future work needed toward commercializing the technology is discussed.

  9. SYMPATHETIC SKIN RESPONSE AND GALVANIC SKIN RESISTANCE IN MALES WITH TYPE 2 DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    Saravanan Mohanraj

    2016-06-01

    Full Text Available BACKGROUND Diabetes mellitus, a metabolic disorder affects the nervous system due to alteration in various metabolic pathways. As neuropathy manifests in longstanding diabetes mellitus, autonomic nervous system also gets affected. The study was started based on the hypothesis that the sweat glands innervated by autonomic nervous system will be affected in patients with type 2 diabetes mellitus patients with clinical features of neuropathy. This study was undertaken to compare the sympathetic skin response (SSR and galvanic skin resistance (GSR in males with type 2 diabetes mellitus and in controls. METHODS Thirty males in the age group of 45-55 years, known to have diabetes mellitus and having a history of neuropathic symptoms served as subjects and thirty males in the same age group with no history of diabetes mellitus and neuropathy served as controls. SSR and GSR were recorded using Recorders and Medicare Systems 4 channel polygraph in the noise and light reduced research laboratory, Department of Physiology. All the recordings were done between 10-12 noon at ambient temperature. SSR was measured by deep inspiration and the GSR was measured in the supine and standing response. Comparison of latency and amplitude of the sympathetic skin response and the percentage of decrease in galvanic skin resistance was done. RESULT A statistically significant delay in the latency and a reduction in the amplitude of sympathetic skin response was observed in the diabetes patients. There was a lesser percentage of decrease in GSR in the diabetic patients. CONCLUSION This study shows that the SSR and GSR responses are significantly reduced in diabetic individuals and can be used as a diagnostic tool in the detection of diabetic autonomic neuropathy.

  10. Dynamic Simulation of Batch Photocatalytic Reactor (BPR) for Wastewater Treatment

    Science.gov (United States)

    Dutta, Suman

    2012-08-01

    Reactive dyes discharged from dyehouse causes a serious environmental problem. UV/TiO2 photocatalysis has been employed effectively for these organic dyes removal from dye-house effluent. This process produces less amount of non-toxic final product. In this paper a photocatalytic reactor has been designed for Reactive red 198 (RR198) removal from aqueous solution. The reactor is operating in batch mode. After each batch, TiO2 catalyst has been separated and recycled in the next batch. Mathematical model equation of this batch photocatalytic reactor (BPR) has been developed considering Langmuir-Hinshelwood kinetics. Simulation of BPR has been carried out using fourth order Runge-Kutta (RK) method and fifth order RK method (Butcher method). This simulation results can be used to develop an automatic photocatlytic reactor for industrial wastewater treatment. Catalyst activity decay and its effect on each batch have been incorporated in this model.

  11. A canned food scheduling problem with batch due date

    Science.gov (United States)

    Chung, Tsui-Ping; Liao, Ching-Jong; Smith, Milton

    2014-09-01

    This article considers a canned food scheduling problem where jobs are grouped into several batches. Jobs can be sent to the next operation only when all the jobs in the same batch have finished their processing, i.e. jobs in a batch, have a common due date. This batch due date problem is quite common in canned food factories, but there is no efficient heuristic to solve the problem. The problem can be formulated as an identical parallel machine problem with batch due date to minimize the total tardiness. Since the problem is NP hard, two heuristics are proposed to find the near-optimal solution. Computational results comparing the effectiveness and efficiency of the two proposed heuristics with an existing heuristic are reported and discussed.

  12. On the track of fish batches in three distribution networks

    DEFF Research Database (Denmark)

    Randrup, Maria; Wu, Haiping; Jørgensen, Bo M.

    2012-01-01

    Three fish products sampled in retail shops were traced back to their origin and fish from the same batch were tracked forward towards the retailer, thereby simulating a recall situation. The resulting distribution networks were very complex, but to the extent that companies were willing to provide...... the necessary information, it was possible to locate the end destinations of the fish batches. The batch sizes and the number of companies involved clearly rose when batch joining occurred. Thus, a fault in a small batch can potentially have widespread implications. The study also underlines the importance...... of discovering a fault as early as possible in order to minimise the costs of a recall. The localisation of distributed products during a recall operation can be facilitated by a well-constructed traceability system....

  13. Batch Delivery Scheduling with Multiple Decentralized Manufacturers

    Directory of Open Access Journals (Sweden)

    Shi Li

    2014-01-01

    Full Text Available This paper addresses an integrated decision on production scheduling and delivery operations, which is one of the most important issues in supply chain scheduling. We study a model in which a set of jobs ordered by only one customer and a set of decentralized manufacturers located at different locations are considered. Specifically, each job must be assigned to one of the decentralized manufacturers to process on its single machine facility. Then, the job is delivered to the customer directly in batch without intermediate inventory. The objective is to find a joint schedule of production and distribution to optimize the customer service level and delivery cost. In our work, we discuss this problem considering two different situations in terms of the customer service level. In the first one, the customer service is measured by the maximum arrival time, while the customer service is measured by the total arrival time in the second one. For each situation, we develop a dynamic programming algorithm to solve, respectively. Moreover, we identify a special case for the latter situation by introducing its corresponding solutions.

  14. Biodenitrification in Sequencing Batch Reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Silverstein, J. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering

    1996-01-23

    One plan for stabilization of the Solar Pond waters and sludges at Rocky Flats Plant (RFP), is evaporation and cement solidification of the salts to stabilize heavy metals and radionuclides for land disposal as low-level mixed waste. It has been reported that nitrate (NO{sub 3}{sub {minus}}) salts may interfere with cement stabilization of heavy metals and radionuclides. Therefore, biological nitrate removal (denitrification) may be an important pretreatment for the Solar Pond wastewaters at RFP, improving the stability of the cement final waste form, reducing the requirement for cement (or pozzolan) additives and reducing the volume of cemented low-level mixed waste requiring ultimate disposal. A laboratory investigation of the performance of the Sequencing Batch Reactor (SBR) activated sludge process developed for nitrate removal from a synthetic brine typical of the high-nitrate and high-salinity wastewaters in the Solar Ponds at Rocky Flats Plant was carried out at the Environmental Engineering labs at the University of Colorado, Boulder, between May 1, 1994 and October 1, 1995.

  15. Biodegradability of industrial textile wastewater - batch tests.

    Science.gov (United States)

    Paździor, Katarzyna; Klepacz-Smółka, Anna; Wrębiak, Julita; Liwarska-Bizukojć, Ewa; Ledakowicz, Stanisław

    Following new trends we applied oxygen uptake rate (OUR) tests as well as long-term tests (in two batch bioreactors systems) in order to assess the biodegradability of textile wastewater. Effluents coming from a dyeing factory were divided into two streams which differed in inorganic and organic contaminants loads. Usefulness of the stream division was proved. Biodegradation of the low-loaded stream led to over 97% reduction of biochemical oxygen demand (BOD5) together with 80% reduction of chemical oxygen demand (COD) and total organic carbon (TOC). Most of the controlled parameter values were below the levels allowed by legislation for influents to surface water, whereas the high-loaded stream was so contaminated with recalcitrant organic compounds that despite the reduction of BOD5 by over 95%, COD, TOC, total nitrogen and total phosphorus levels exceeded permissible values. OUR tests were aimed at determination of the following kinetic parameters: maximum specific growth rate (μMax), half-saturation constant, hydrolysis constant and decay coefficient for activated sludge biomass for both types of textile wastewater studied. The values of kinetic parameters will be applied in activated sludge models used for prediction and optimisation of biological treatment of textile wastewater.

  16. Glucoamylase production in batch, chemostat and fed-batch cultivations by an industrial strain of Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Beyer, Michael; Nielsen, Jens

    2000-01-01

    The Aspergillus niger strain BO-1 was grown in batch, continuous (chemostat) and fed-batch cultivations in order to study the production of the extracellular enzyme glucoamylase under different growth conditions. In the pH range 2.5-6.0, the specific glucoamylase productivity and the specific gro...

  17. Kinetic study of batch and fed-batch enzymatic saccharification of pretreated substrate and subsequent fermentation to ethanol

    Directory of Open Access Journals (Sweden)

    Gupta Rishi

    2012-03-01

    Full Text Available Abstract Background Enzymatic hydrolysis, the rate limiting step in the process development for biofuel, is always hampered by its low sugar concentration. High solid enzymatic saccharification could solve this problem but has several other drawbacks such as low rate of reaction. In the present study we have attempted to enhance the concentration of sugars in enzymatic hydrolysate of delignified Prosopis juliflora, using a fed-batch enzymatic hydrolysis approach. Results The enzymatic hydrolysis was carried out at elevated solid loading up to 20% (w/v and a comparison kinetics of batch and fed-batch enzymatic hydrolysis was carried out using kinetic regimes. Under batch mode, the actual sugar concentration values at 20% initial substrate consistency were found deviated from the predicted values and the maximum sugar concentration obtained was 80.78 g/L. Fed-batch strategy was implemented to enhance the final sugar concentration to 127 g/L. The batch and fed-batch enzymatic hydrolysates were fermented with Saccharomyces cerevisiae and ethanol production of 34.78 g/L and 52.83 g/L, respectively, were achieved. Furthermore, model simulations showed that higher insoluble solids in the feed resulted in both smaller reactor volume and shorter residence time. Conclusion Fed-batch enzymatic hydrolysis is an efficient procedure for enhancing the sugar concentration in the hydrolysate. Restricting the process to suitable kinetic regimes could result in higher conversion rates.

  18. Glucoamylase production in batch, chemostat and fed-batch cultivations by an industrial strain of Aspergillus niger

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Beyer, Michael; Nielsen, Jens

    2000-01-01

    The Aspergillus niger strain BO-1 was grown in batch, continuous (chemostat) and fed-batch cultivations in order to study the production of the extracellular enzyme glucoamylase under different growth conditions. In the pH range 2.5-6.0, the specific glucoamylase productivity and the specific...

  19. Multi-objective optimization of glycopeptide antibiotic production in batch and fed batch processes

    DEFF Research Database (Denmark)

    Maiti, Soumen K.; Eliasson Lantz, Anna; Bhushan, Mani

    2011-01-01

    as pareto optimal solutions. These solutions gives flexibility in evaluating the trade-offs and selecting the most suitable operating policy. Here, ε-constraint approach was used to generate the pareto solutions for two objectives: product concentration and product per unit cost of media, for batch and fed......Fermentation optimization involves potentially conflicting multiple objectives such as product concentration and production media cost. Simultaneous optimization of these objectives would result in a multiobjective optimization problem, which is characterized by a set of multiple solutions, knows...

  20. FRIT DEVELOPMENT FOR SLUDGE BATCH 6

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Edwards, T.; Zamecnik, J.

    2010-05-13

    The Savannah River National Laboratory (SRNL) evaluated a large number of Sludge Batch 6 (SB6) composition projections to support frit optimization for SB6 vitrification at the Defense Waste Processing Facility (DWPF). The evaluations discussed in this report occurred over a period of about 4 months, and included about 40 composition projections, developed by both Savannah River Remediation (SRR) and SRNL. Paper study assessments were used to evaluate the sludge composition projections with arrays of potential frit compositions using the predictive models in the DWPF Product Composition Control System (PCCS). Both nominal sludge compositions and sludge compositions with anticipated compositional variation were considered. The model predictions were used to identify candidate frit compositions for each SB6 projection and to provide some guidance to SRR on washing and blending strategies for SB6 preparation. This report presents a chronological review of this process and summarizes the findings at each stage. Following initial feedback from this work, the number of washes in Tank 51 was reduced to increase the projected sodium concentration in SB6. Analyses of predicted frit performance before and after a potential decant of Tank 40 showed that the post-decant SB6 composition would be difficult to process with any frit composition and that this scenario should be avoided. Based on the most recent SB6 projections (February 2010 SB6 composition projections developed at SRNL using the measured SB6 qualification sample composition and the revised Tank Farm washing plan), Frit 418 appears to be viable for SB6 processing at a target waste loading of 36%. A Nominal Stage PCCS Measurement Acceptability Region (MAR) assessment gave projected operating windows of 25-41% waste loading, limited by predictions of nepheline crystallization. The projected operating window is reduced to 25-38% waste loading when anticipated compositional variation is considered, again limited by

  1. A New Batch Verifying Scheme for Identifying Illegal Signatures

    Institute of Scientific and Technical Information of China (English)

    Adrian Atanasiu

    2013-01-01

    The concept of batch verifying multiple digital signatures is to find a method by which multiple digital signatures can be verified simultaneously in a lower time complexity than separately verifying all the signatures.In this article,we analyze the complexity of the batch verifying schemes defined by Li,Hwang and Chen in 2010,and propose a new batch verifying multiple digital signature scheme,in two variants:one for RSA-by completing the Harn's schema with an identifying illegal signatures algorithm,and the other adapted for a modified Elliptic Curve Digital Signature Algorithm protocol.

  2. Structural and optical properties of dense vertically aligned ZnO nanorods grown onto silver and gold thin films by galvanic effect with iron contamination

    Energy Technology Data Exchange (ETDEWEB)

    Scarpellini, D.; Paoloni, S.; Medaglia, P.G. [Department of Industrial Engineering, University of Rome “Tor Vergata”, 00133 Rome (Italy); Pizzoferrato, R., E-mail: pizzoferrato@uniroma2.it [Department of Industrial Engineering, University of Rome “Tor Vergata”, 00133 Rome (Italy); Orsini, A.; Falconi, C. [Department of Electronic Engineering, University of Rome “Tor Vergata”, 00133 Rome (Italy)

    2015-05-15

    Highlights: • ZnO nanorods were grown on Au and Ag films in aqueous solution by galvanic effect. • The method is prone to metal contamination which can influence the ZnO properties. • Iron doping improves the lattice matching between ZnO and the substrate. • Energy levels of point defects are lowered and the light emission is red-shifted. • Galvanic-induced nucleation starts and proceeds continuously during the growth. - Abstract: Dense arrays of vertically aligned ZnO nanorods have been grown onto either silver or gold seedless substrates trough a simple hydrothermal method by exploiting the galvanic effect between the substrate and metallic parts. The nanorods exhibit larger bases and more defined hexagonal shapes, in comparison with standard non-galvanic wet-chemistry synthesis. X-ray diffraction (XRD) shows that the iron contamination, associated with the galvanic contact, significantly improves the in-plane compatibility of ZnO with the Au and Ag cubic lattice. Photoluminescence (PL) measurements indicate that the contamination does not affect the number density of localized defects, but lowers their energy levels uniformly; differently, the band-edge emission is not altered appreciably. Finally, we have found that the ZnO hetero-nucleation by galvanic effect initiates at different times in different sites of the substrate area. Our results can be useful for the fabrication of high performance piezonanodevices comprising high-density metal-to-ZnO nanoscaled junctions without intermediate polycrystalline layers.

  3. 超薄锌层热镀锌板的研究进展%Research Progress of Ultra-thin Zinc Layer of Hot Galvanized Sheet

    Institute of Scientific and Technical Information of China (English)

    岑耀东

    2012-01-01

    The production and usage of hot galvanized sheet were introduced. The market demand for the ultra-thin zinc layer of hot galvanized sheet was analyzed from improving unit production capacity and reducing production cost. By comparing the advantages and disadvantages of the hot galvanized sheet and the electricity galvanized sheet, the specific measures taken by the current hot galvanized sheet in aspects of control of the ultra-thin zinc layer were reviewed. The development prospects of the ultra-thin zinc layer of hot galvanized sheet in China was forecasted.%介绍了我国热镀锌板的生产及使用现状,从提高机组生产能力和降低生产成本方面分析了市场对薄锌层镀锌板的需求.通过对电镀锌板与热镀锌板优缺点的比较,综述了当前热镀锌板在超薄锌层控制方面所采取的措施,预测了我国超薄锌层热镀锌板的发展前景.

  4. Comportamiento Frente a la Corrosión en Ambiente Marino de Acero Galvanizado y Acero Galvanizado Pintado (Duplex Corrosion Behaviour of Galvanized and Coated Galvanized Steel (Duplex in Marine Environment

    Directory of Open Access Journals (Sweden)

    R.M. Vera

    2005-01-01

    Full Text Available En este estudio se evaluó el comportamiento frente a la corrosión en medio marino de acero galvanizado y acero galvanizado pintado (Duplex haciendo uso de ensayos electroquímicos y acelerados de laboratorio. Las medidas electroquímicas consideraron potencial de corrosión a circuito abierto, curvas de polarización y polarización potenciostática en cloruro de sodio 0.1M. Los ensayos acelerados se realizaron en cámara de niebla salina y con el método Cebelcor. El grado de ataque del material se observó por microscopia electrónica de barrido. Los resultados muestran que el sistema Duplex presenta un mejor comportamiento frente la corrosión en medio de cloruros que el acero galvanizado, aumentando su durabilidad en el tiempo.This study evaluated the resistence to corrosion of galvanized and painted galvanized (Duplex steel in a marine environment using electrochemical and accelerated laboratory essays. The electrochemical measurements included open circuit potential, polarization curves, and potentiostatic polarization in 0.1M sodium chloride. The accelerated essays were carried out in a saline fog chamber and also using the Cebelcor method. The degree of corrosion attack of the material was observed by scanning electronic microscopy. The results show that the Duplex system presents a better behaviour against corrosion in chloride media than galvanized steel, increasing its useful life.

  5. Evaluation of Corrosion Behavior of Galvanized Steel Treated with Conventional Conversion Coatings and a Chromate-Free Organic Inhibitor

    Directory of Open Access Journals (Sweden)

    Laura A. Hernandez-Alvarado

    2012-01-01

    Full Text Available Conventional weight loss tests and both DC and AC electrochemical techniques were used to study if an organic inhibitor containing an alkanolamine salt of a polycarboxylic acid can substitute toxic coatings as chromating and certain phosphating procedures in the protection of galvanized steel. The electrolyte used was a 0.5 M aerated NaCl solution. All tests gave concordant results, indicating that the chromate-free organic inhibitor does protect galvanized steel in this environment, even though the provided protection was less than that of the chromate conversion coating. It was observed that, after a moderate initial attack, the corrosion rate diminishes due to the appearance and growth of passivating corrosion products layers, mainly constituted by zinc hydroxychloride (Zn5(OH8CI2⋅H2O and two varieties of zinc hydroxide, among other crystalline compounds.

  6. Galvanic couples of 316L steel with Ti and ion plated Ti and TiN coatings in Ringer's solutions.

    Science.gov (United States)

    Gluszek, J; Jedrkowiak, J; Markowski, J; Masalski, J

    1990-07-01

    Steel 316L was coated with titanium or titanium nitride by ion plating. The tightness of the coatings was examined electro-chemically. The galvanic effects for the galvanic couples steel-titanium, steel-titanium-coated steel and steel-titanium nitride-coated steel were studied. It was found that both titanium and titanium nitride coatings were non-porous in Ringer's solution; titanium served as an anode in the couple steel-titanium; it was oxidized according to the logarithmic law. For the other two couples, the coatings were the cathodes. The rate of dissolution of steel in these couples, was however, smaller than expected, owing to a strong polarization of the coatings. The potential of the couple was similar to that of steel.

  7. Fabrication of dendritic silver-coated copper powders by galvanic displacement reaction and their thermal stability against oxidation

    Science.gov (United States)

    Park, Yu-Seon; An, Chang Yong; Kannan, Padmanathan Karthick; Seo, Nary; Zhuo, Kai; Yoo, Tae Kyong; Chung, Chan-Hwa

    2016-12-01

    Two steps of wet chemical processes have been developed for the preparation of core-shell nanostructures of copper and silver, which is a facile and low cost method for the production of large quantity of dendritic powders. First step involves a galvanic displacement reaction with hydrogen evolution which is the motive force of spontaneous electrochemical reaction. To achieve the core-shell structure, silver has been coated on the dendritic copper using the galvanic displacement reaction. The dendritic silver-coated copper powders exhibit high surface-area, excellent conductivity, and good oxidation resistance. It has been found that silver-coated copper powders maintain the electrical conductivity even after annealing at 150 °C for several to tens of minutes, thus it is a promising material and an alternative to pure silver powders in printed electronics application.

  8. Study of the Reaction Rate of Gold Nanotube Synthesis from Sacrificial Silver Nanorods through the Galvanic Replacement Method

    Directory of Open Access Journals (Sweden)

    Sunil Kwon

    2010-01-01

    Full Text Available An investigation was carried out about the gold nanotube synthesis via a galvanic replacement reaction. The progress of the gold nanotube synthesis was investigated using electron microscopy and UV-Vis spectroscopy. In addition, the reaction rates of gold nanotube formation in the early stage of the reaction were studied. The chlorine ion concentration linearly increased with the gold precursor concentration but deviated from the stoichiometric amounts. This deviation was probably due to AgCl precipitates formed by the reaction of chlorine ions with dissolved silver ions. The replacement reaction was promoted with increased temperature and was nonlinearly proportional to the gold ion concentration. The outcomes of this research will enhance the current understanding of the galvanic replacement reaction.

  9. Hybrid laser-arc welding of galvanized high-strength steels in a gap-free lap-joint configuration

    Science.gov (United States)

    Yang, Shanglu

    In order to meet the industry demands for increased fuel efficiency and enhanced mechanical and structural performance of vehicles as well as provided excellent corrosion resistance, more and more galvanized advanced high-strength steels (AHSS) have been used to fabricate automobile parts such as panels, bumpers, and front rails. The automotive industry has shown tremendous interest in using laser welding to join galvanized dual phase steels because of lower heat input and higher welding speed. However, the laser welding process tends to become dramatically unstable in the presence of highly pressurized zinc vapor because of the low boiling point of zinc, around 906°C, compared to higher melting point of steel, over 1500°C. A large number of spatters are produced by expelling the liquid metal from the molten pool by the pressurized zinc vapor. Different weld defects such as blowholes and porosities appear in the welds. So far, limited information has been reported on welding of galvanized high strength dual-phase steels in a gap-free lap joint configuration. There is no open literature on the successful attainment of defect-free welds from the laser or hybrid welding of galvanized high-strength steels. To address the significant industry demand, in this study, different welding techniques and monitoring methods are used to study the features of the welding process of galvanized DP steels in a gap-free lap joint configuration. The current research covers: (i) a feasibility study on the welding of galvanized DP 980 steels in a lap joint configuration using gas tungsten arc welding (GTAW), laser welding, hybrid laser/arc welding with the common molten pool, laser welding with the assistance of GTAW preheating source and hybrid laser-variable polarity gas tungsten arc welding (Laser-VPGTAW) techniques (Chapter 2-4); (ii) a welding process monitoring of the welding techniques including the use of machine vision and acoustic emission technique (Chapter 5); (iii

  10. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  11. Galvanic-cell-induced growth of Ag nanosheet-assembled structures as sensitive and reproducible SERS substrates.

    Science.gov (United States)

    Li, Zhongbo; Meng, Guowen; Huang, Qing; Zhu, Chuhong; Zhang, Zhuo; Li, Xiangdong

    2012-11-19

    SERS up: Ag nanosheet-assembled structures with controlled morphologies were achieved on indium tin oxide substrates by galvanic-cell-induced growth (see figure). These structures exhibit a highly active and homogeneous surface-enhanced Raman scattering (SERS) effect, and show promising potential as reliable SERS substrates for detection of trace polychlorinated biphenyls. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Study of the Reaction Rate of Gold Nanotube Synthesis from Sacrificial Silver Nanorods through the Galvanic Replacement Method

    OpenAIRE

    Sunil Kwon; Hyunbae Dong; Sang-Yup Lee

    2010-01-01

    An investigation was carried out about the gold nanotube synthesis via a galvanic replacement reaction. The progress of the gold nanotube synthesis was investigated using electron microscopy and UV-Vis spectroscopy. In addition, the reaction rates of gold nanotube formation in the early stage of the reaction were studied. The chlorine ion concentration linearly increased with the gold precursor concentration but deviated from the stoichiometric amounts. This deviation was probably due to AgCl...

  13. Precise measurement of effective oxygen diffusivity for microporous media containing moisture by review of galvanic cell oxygen absorber configuration

    OpenAIRE

    Koresawa, Ryo; Utaka, Yoshio

    2014-01-01

    The performance of polymer electrolyte fuel cells is influenced by moisture control in their gas diffusion layer (GDL). Therefore, to achieve suitable control, it is necessary to clarify the mass transfer characteristics within a GDL by high precision measurement of oxygen diffusivity. We have previously proposed that measurement of the effective oxygen diffusivity in a GDL containing moisture can be achieved using a galvanic cell oxygen absorber and demonstrated this to be an effective techn...

  14. Synthesis of zero effluent multipurpose batch processes using effective scheduling

    CSIR Research Space (South Africa)

    Gouws, JF

    2008-06-01

    Full Text Available that characterize today’s markets. Secondly, batch processes tend to produce highly toxic effluent streams, albeit in relatively small quantities in comparison to their continuous counterparts. The stringent environmental conditions militate against the latter...

  15. Numerical modeling of batch formation in waste incineration plants

    Directory of Open Access Journals (Sweden)

    Obroučka Karel

    2015-03-01

    Full Text Available The aim of this paper is a mathematical description of algorithm for controlled assembly of incinerated batch of waste. The basis for formation of batch is selected parameters of incinerated waste as its calorific value or content of pollutants or the combination of both. The numerical model will allow, based on selected criteria, to compile batch of wastes which continuously follows the previous batch, which is a prerequisite for optimized operation of incinerator. The model was prepared as for waste storage in containers, as well as for waste storage in continuously refilled boxes. The mathematical model was developed into the computer program and its functionality was verified either by practical measurements or by numerical simulations. The proposed model can be used in incinerators for hazardous and municipal waste.

  16. Giant Temperature Coefficient of Resistivity and Cryogenic Sensitivity in Silicon with Galvanically Displaced Gold Nanoparticles in Freeze-Out Region.

    Science.gov (United States)

    Lee, Seung-Hoon; Hwang, Seongpil; Jang, Jae-Won

    2017-02-28

    The temperature coefficient of resistivity (TCR) and cryogenic sensitivity (Sv) of p-type silicon (p-Si) in the low-temperature region (10-30 K) are remarkably improved by increasing the coverage of galvanically displaced Au nanoparticles (NPs). By increase of the galvanic displacement time from 10 to 30 s, the average surface roughness (Ra) of the samples increases from 0.31 to 2.31 nm and the coverage rate of Au NPs increases from 3.1% to 21.9%. In the freeze-out region of the sample, an up to 103% increase of TCR and dramatically improved Sv of p-Si (∼5813%) are observed with Au coverage of 21.9% compared to p-Si without galvanically displaced Au NPs. By means of a finite element method (FEM) simulation study, it was found that the increase of surface roughness and a number of Au NPs on p-Si results in a higher temperature gradient and thermoelectric power to cause the unusual TCR and Sv values in the samples.

  17. Saccule contribution to immediate early gene induction in the gerbil brainstem with posterior canal galvanic or hypergravity stimulation.

    Science.gov (United States)

    Marshburn, T H; Kaufman, G D; Purcell, I M; Perachio, A A

    1997-06-27

    Immunolabeling patterns of the immediate early gene-related protein Fos in the gerbil brainstem were studied following stimulation of the sacculus by both hypergravity and galvanic stimulation. Head-restrained, alert animals were exposed to a prolonged (1 h) inertial vector of 2 G (19.6 m/s2) head acceleration directed in a dorso-ventral head axis to maximally stimulate the sacculus. Fos-defined immunoreactivity was quantified, and the results compared to a control group. The hypergravity stimulus produced Fos immunolabeling in the dorsomedial cell column (dmcc) of the inferior olive independently of other subnuclei. Similar dmcc labeling was induced by a 30 min galvanic stimulus of up to -100 microA applied through a stimulating electrode placed unilaterally on the bony labyrinth overlying the posterior canal (PC). The pattern of vestibular afferent firing activity induced by this galvanic stimulus was quantified in anesthetized gerbils by simultaneously recording from Scarpa's ganglion. Only saccular and PC afferent neurons exhibited increases in average firing rates of 200-300%, suggesting a pattern of current spread involving only PC and saccular afferent neurons at this level of stimulation. These results suggest that alteration in saccular afferent firing rates are sufficient to induce Fos-defined genomic activation of the dmcc, and lend further evidence to the existence of a functional vestibulo-olivary-cerebellar pathway of adaptation to novel gravito-inertial environments.

  18. Saccule contribution to immediate early gene induction in the gerbil brainstem with posterior canal galvanic or hypergravity stimulation

    Science.gov (United States)

    Marshburn, T. H.; Kaufman, G. D.; Purcell, I. M.; Perachio, A. A.

    1997-01-01

    Immunolabeling patterns of the immediate early gene-related protein Fos in the gerbil brainstem were studied following stimulation of the sacculus by both hypergravity and galvanic stimulation. Head-restrained, alert animals were exposed to a prolonged (1 h) inertial vector of 2 G (19.6 m/s2) head acceleration directed in a dorso-ventral head axis to maximally stimulate the sacculus. Fos-defined immunoreactivity was quantified, and the results compared to a control group. The hypergravity stimulus produced Fos immunolabeling in the dorsomedial cell column (dmcc) of the inferior olive independently of other subnuclei. Similar dmcc labeling was induced by a 30 min galvanic stimulus of up to -100 microA applied through a stimulating electrode placed unilaterally on the bony labyrinth overlying the posterior canal (PC). The pattern of vestibular afferent firing activity induced by this galvanic stimulus was quantified in anesthetized gerbils by simultaneously recording from Scarpa's ganglion. Only saccular and PC afferent neurons exhibited increases in average firing rates of 200-300%, suggesting a pattern of current spread involving only PC and saccular afferent neurons at this level of stimulation. These results suggest that alteration in saccular afferent firing rates are sufficient to induce Fos-defined genomic activation of the dmcc, and lend further evidence to the existence of a functional vestibulo-olivary-cerebellar pathway of adaptation to novel gravito-inertial environments.

  19. Can galvanic skin conductance be used as an objective indicator of children’s anxiety in the dental setting?

    Science.gov (United States)

    Najafpour, Ebrahim; Asl-Aminabadi, Naser; Nuroloyuni, Sara; Jamali, Zahra

    2017-01-01

    Background Assessment of procedural distress is essential at assisting children during invasive dental treatments. This study aimed to determine the validity and reliability of galvanic skin response as a measure for assessment of dental anxiety in children. Material and Methods 151 children, aged 5-7 years, participated in this study. Similar dental treatments were rendered to all subjects. At the beginning and end of the session, modified child dental anxiety scale (MCDAS), clinical anxiety rating scale (CARS) and galvanic skin response (GSR) were used to determine children’s anxiety. Results GSR was significantly correlated with both MCDAS (rs=0.62, p=0.02) and CARS (rs=0.44, p=0.032). The correlation between MCDAS and CARS was also significant (rs = 0.9, P<0.001). Anxiety decreased during the session in both GSR (rs=0.52, p=0.001) and MCDAS scales (rs=0.77, p=0.001). CARS also showed a reduction between the initial and second assessment, but it was not statistically significant (rs=0.12, P=0.36). Conclusions The findings suggest that GSR is a reliable and valid measure for assessment of children’s dental anxiety in the clinical context. GSR may help to identify clinically anxious children before dental treatment to provide appropriate interventions. Key words:Dental anxiety, reliability, validity, galvanic skin response. PMID:28298978

  20. Synthesis of Pd-Pt bimetallic nanocrystals with a concave structure through a bromide-induced galvanic replacement reaction.

    Science.gov (United States)

    Zhang, Hui; Jin, Mingshang; Wang, Jinguo; Li, Weiyang; Camargo, Pedro H C; Kim, Moon J; Yang, Deren; Xie, Zhaoxiong; Xia, Younan

    2011-04-20

    This article describes a systematic study of the galvanic replacement reaction between PtCl(6)(2-) ions and Pd nanocrystals with different shapes, including cubes, cuboctahedrons, and octahedrons. It was found that Br(-) ions played an important role in initiating, facilitating, and directing the replacement reaction. The presence of Br(-) ions led to the selective initiation of galvanic replacement from the {100} facets of Pd nanocrystals, likely due to the preferential adsorption of Br(-) ions on this crystallographic plane. The site-selective galvanic replacement resulted in the formation of Pd-Pt bimetallic nanocrystals with a concave structure owing to simultaneous dissolution of Pd atoms from the {100} facets and deposition of the resultant Pt atoms on the {111} facets. The Pd-Pt concave nanocubes with different weight percentages of Pt at 3.4, 10.4, 19.9, and 34.4 were also evaluated as electrocatalysts for the oxygen reduction reaction (ORR). Significantly, the sample with a 3.4 wt.% of Pt exhibited the largest specific electrochemical surface area and was found to be four times as active as the commercial Pt/C catalyst for the ORR in terms of equivalent Pt mass.

  1. Degeneration of the vestibular nerve in unilateral Meniere's disease evaluated by galvanic vestibular-evoked myogenic potentials.

    Science.gov (United States)

    Chang, Chih-Ming; Young, Yi-Ho; Jaw, Fu-Shan; Wang, Chi-Te; Cheng, Po-Wen

    2017-09-01

    The staging system of Meniere's disease utilizes audiograms to probe cochlear dysfunction. We explored the addition of galvanic vestibular-evoked myogenic potentials (VEMP) to further explore vestibular function. Seventy patients with unilateral Meniere's disease were enrolled in this study. Within 2weeks of diagnosis, all subjects underwent pure tone audiometry, cervical and ocular VEMP, and caloric test. The prevalence of abnormal tests and the VEMP characteristic parameters such as latencies and amplitudes were analyzed. In affected ears, the abnormal rate of acoustic cVEMPs, galvanic cVEMPs, vibratory oVEMPs and galvanic oVEMPs was 37%, 17%, 20%, and 9%, respectively. No significant differences existed in VEMP latencies and amplitudes between affected ears and unaffected ears. The impairment of otolithic organs was found to be more than that of vestibular afferents. The deterioration of the saccule was more than that of the utricle, whereas retrolabyrinthine degeneration of sacculo-collic reflex and vestibulo-ocular reflex was similar. This study is the first to use an electrophysiological test to evaluate the retrolabyrinthine function of patients with unilateral Meniere's disease. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  2. Saccule contribution to immediate early gene induction in the gerbil brainstem with posterior canal galvanic or hypergravity stimulation

    Science.gov (United States)

    Marshburn, T. H.; Kaufman, G. D.; Purcell, I. M.; Perachio, A. A.

    1997-01-01

    Immunolabeling patterns of the immediate early gene-related protein Fos in the gerbil brainstem were studied following stimulation of the sacculus by both hypergravity and galvanic stimulation. Head-restrained, alert animals were exposed to a prolonged (1 h) inertial vector of 2 G (19.6 m/s2) head acceleration directed in a dorso-ventral head axis to maximally stimulate the sacculus. Fos-defined immunoreactivity was quantified, and the results compared to a control group. The hypergravity stimulus produced Fos immunolabeling in the dorsomedial cell column (dmcc) of the inferior olive independently of other subnuclei. Similar dmcc labeling was induced by a 30 min galvanic stimulus of up to -100 microA applied through a stimulating electrode placed unilaterally on the bony labyrinth overlying the posterior canal (PC). The pattern of vestibular afferent firing activity induced by this galvanic stimulus was quantified in anesthetized gerbils by simultaneously recording from Scarpa's ganglion. Only saccular and PC afferent neurons exhibited increases in average firing rates of 200-300%, suggesting a pattern of current spread involving only PC and saccular afferent neurons at this level of stimulation. These results suggest that alteration in saccular afferent firing rates are sufficient to induce Fos-defined genomic activation of the dmcc, and lend further evidence to the existence of a functional vestibulo-olivary-cerebellar pathway of adaptation to novel gravito-inertial environments.

  3. Performance of plain and galvanized reinforcing steel during the initiation stage of corrosion in concrete with pozzolanic additions

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, E.I.; Saguees, A.A. [Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering; Powers, R.G. [Florida Dept. of Transportation, Gainesville, FL (United States). Materials Office

    1996-11-01

    The pH of the concrete pore solution is expected to be somewhat lower in concretes using pozzolanic additions than in concrete using unblended cements. Variations in pH pore solution may hold the key to explaining conflicting reports on the performance of galvanized rebar. To examine that factor, plain and galvanized rebars have been tested for over two years in concrete specimens made with cement type 2, with various contents of fly ash and silica fume. Electrochemical impedance measurements and sensitive polarization techniques have been used to measure the rate of metal dissolution in the absence of chloride contamination at two different levels of concrete moisture. The plain steel specimens have shown little tendency for passivation in two of the cement compositions with the highest levels of pozzolanic addition. The galvanized steel passivated in all cases and showed apparent corrosion current densities of less than 0.3 {micro}A near the end of the test. Implications of the length of the corrosion initiation period and on current materials selection criteria are presented.

  4. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function.

    Science.gov (United States)

    Reinis, S; Landolt, J P; Weiss, D S; Money, K E

    1984-03-01

    /he spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent (14)--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique (19). Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. In cats with intact labyrinths, D2O changed the optimal length of the light bar that was able to stimulate the cortical cell as well as the path on which it evoked the response of the cell. Both values, which constitute the receptive field of the cell, changed approximately proportionately. This effect usually lasts for less than 4.5 h. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells (and the other cellular characteristics studied) did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease

  5. Statistical strategies for microRNAseq batch effect reduction

    OpenAIRE

    Guo,Yan; Zhao, Shilin; Su, Pei-Fang; Li, Chung-I; Ye, Fei; Flynn, Charles R.; Shyr, Yu

    2014-01-01

    RNAseq technology is replacing microarray technology as the tool of choice for gene expression profiling. While providing much richer data than microarray, analysis of RNAseq data has been much more challenging. Among the many difficulties of RNAseq analysis, correctly adjusting for batch effect is a pivotal one for large-scale RNAseq based studies. The batch effect of RNAseq data is most obvious in microRNA (miRNA) sequencing studies. Using real miRNA sequencing (miRNAseq) dat...

  6. Optimal control of a fed-batch fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Dekkers, R.M.

    1984-01-01

    The common cultivation of bakers' yeast is an aerobic fed-batch fermentation under sugar-limited growth. The ultimate objective of on-line computer control is to optimize the process through maximizing the productivity of biomass formation while minimizing the consumption of raw materials for the product. Results obtained on the optimal control of a fed-batch fermentation are given. The aspects to be considered are instrumentation, state estimation, optimization and process control.

  7. Differences of silicon photodiode spectral reflectance among the same batch

    Institute of Scientific and Technical Information of China (English)

    A.L.Mu(n)oz Zurita; J.Campos Acosta; A.Pons Aglio; A.Shcherbakov

    2008-01-01

    Photodiode's reflectance plays an important role regarding the relation between responsivity and the incident flux. In this work we analyze how the spectral reflectance changes among photodiodes from the same manufacturer and batch and how the reflectance of three standard photodiodes has drifted during six years. The results show that the reflectance changes from diode to diode within the same batch and also show th.at the reflectance ofphotodiodes changes on time. This ageing is spectrally dependent.

  8. 75 FR 34425 - Certain Steel Nails from the People's Republic of China: Final Results of the First New Shipper...

    Science.gov (United States)

    2010-06-17

    ... limited to, coating in vinyl, zinc (galvanized, whether by electroplating or hot-dipping one or more times), phosphate cement, and paint. Head styles include, but are not limited to, flat, projection, cupped, oval... collated with adhesive or polyester film tape backed with a heat seal adhesive. Also excluded from the...

  9. 77 FR 24462 - Certain Steel Nails From the People's Republic of China: Amended Final Results of the Second...

    Science.gov (United States)

    2012-04-24

    .... Finishes include, but are not limited to, coating in vinyl, zinc (galvanized, whether by electroplating or hot dipping one or more times), ] phosphate cement, and paint. Head styles include, but are not... adhesive or polyester film tape backed with a heat seal adhesive. Also excluded from the scope of the order...

  10. 76 FR 30101 - Certain Steel Nails From the People's Republic of China: Final Results of Antidumping Duty...

    Science.gov (United States)

    2011-05-24

    ... diameters. Finishes include, but are not limited to, coating in vinyl, zinc (galvanized, whether by electroplating or hot dipping one or more times), phosphate cement, and paint. Head styles include, but are not....375 inches and 2.5 inches in length, and that are collated with adhesive or polyester film tape backed...

  11. 76 FR 23279 - Certain Steel Nails From the People's Republic of China: Amended Final Results of the First...

    Science.gov (United States)

    2011-04-26

    ... Works/Stanley Fastening Systems LP, and an unaffiliated wire drawing subcontractor are collectively..., nails made of round wire and nails that are cut. Certain steel nails may be of one piece construction or... are not limited to, coating in vinyl, zinc (galvanized, whether by electroplating or hot-dipping one...

  12. 78 FR 12718 - Certain Steel Threaded Rod From the People's Republic of China: Affirmative Final Determination...

    Science.gov (United States)

    2013-02-25

    ... or coatings, such as plain oil finish as a temporary rust protectant, zinc coating (i.e., galvanized, whether by electroplating or hot-dipping), paint, and other similar finishes and coatings, may be applied... 0.40 percent of lead, or 1.25 percent of nickel, or 0.30 percent of tungsten, or 0.012 percent...

  13. Batch process monitoring based on multilevel ICA-PCA

    Institute of Scientific and Technical Information of China (English)

    Zhi-qiang GE; Zhi-huan SONG

    2008-01-01

    In this paper,we describe a new batch process monitoring method based on multilevel independent component analysis and principal component analysis (MLICA-PCA).Unlike the conventional multi-way principal component analysis (MPCA) method,MLICA-PCA provides a separated interpretation for multilevel batch process data.Batch process data are partitioned into two levels:the within-batch level and the between-batch level.In each level,the Gaussian and non-Ganssian components of process information can be separately extracted.I2,T2 and SPE statistics are individually built and monitored.The new method facilitates fault diagnosis.Since the two variation levels arc decomposed,the variables responsible for faults in each level can be identified and interpreted more easily.A case study of the Dupont benchmark process showed that the proposed method was more efficient and interpretable in fault detection and diagnosis,compared to the alternative batch process monitoring method.

  14. Polynomial Batch Codes for Efficient IT-PIR

    Directory of Open Access Journals (Sweden)

    Henry Ryan

    2016-10-01

    Full Text Available Private information retrieval (PIR is a way for clients to query a remote database without the database holder learning the clients’ query terms or the responses they generate. Compelling applications for PIR are abound in the cryptographic and privacy research literature, yet existing PIR techniques are notoriously inefficient. Consequently, no such PIRbased application to date has seen real-world at-scale deployment. This paper proposes new “batch coding” techniques to help address PIR’s efficiency problem. The new techniques exploit the connection between ramp secret sharing schemes and efficient information-theoretically secure PIR (IT-PIR protocols. This connection was previously observed by Henry, Huang, and Goldberg (NDSS 2013, who used ramp schemes to construct efficient “batch queries” with which clients can fetch several database records for the same cost as fetching a single record using a standard, non-batch query. The new techniques in this paper generalize and extend those of Henry et al. to construct “batch codes” with which clients can fetch several records for only a fraction the cost of fetching a single record using a standard non-batch query over an unencoded database. The batch codes are highly tuneable, providing a means to trade off (i lower server-side computation cost, (ii lower server-side storage cost, and/or (iii lower uni- or bi-directional communication cost, in exchange for a comparatively modest decrease in resilience to Byzantine database servers.

  15. Shortcut Algorithm for Simulation of Batch Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    WU Huixiong; XU Shimin; HU Hui; XIAO Bin

    2007-01-01

    The batch extractive distillation (BED) process has the advantages of both batch and extractive distillation. It is one of the most promising means for the separation of azeotropic and close-boiling point systems. However, so far this process has not been applied in industry due to its over-complexity. A new shortcut model was proposed to simulate the operation of the batch extractive distillation operations. This algorithm is based on the assumption that the batch extractive distillation column can be considered as a continuous extractive distillation column with changing feed at anytime. Namely, the whole batch process is simulated as a succession of a finite number of steady states of short duration, in which holdup is considered as constant mole. For each period of time the batch extractive distillation process is solved through the algorithm for continuous extractive distillation. Finally, the practical implementation of the shortcut model is discussed and data from the lab-oratory and literature are presented. It is found that this model has better adaptability, more satisfactory accuracy and less calculative load than previous rigorous model. Hence the algorithm for simulating BED is verified.

  16. [Characteristic of Particulate Emissions from Concrete Batching in Beijing].

    Science.gov (United States)

    Xue, Yi-feng; Zhou, Zhen; Zhong, Lian-hong; Yan, Jing; Qu, Song; Huang, Yu-hu; Tian, He- zhong; Pan, Tao

    2016-01-15

    With the economic development and population growth in Beijing, there is a strong need for construction and housing, which leads to the increase of the construction areas. Meanwhile, as a local provided material, the production of concrete has been raised. In the process of concrete production by concrete batching, there are numerous particulates emitted, which have large effect on the atmospheric environment, however, systematic study about the tempo-spatial characteristics of pollutant emission from concrete batching is still rare. In this study, we estimated the emission of particulates from concrete batching from 1991 to 2012 using emission factor method, analyzed the tempo-spatial characteristics of pollutant emission, established the uncertainty range by adopting Monte-Carlo method, and predicted the future emission in 2020 based on the relative environmental and economical policies. The results showed that: (1) the emissions of particulates from concrete batching showed a trend of "first increase and then decrease", reaching the maximum in 2005, and then decreased due to stricter emission standard and enhanced environmental management. (2) according to spatial distribution, the emission of particulates from concrete batch mainly concentrated in the urban area with more human activities, and the area between the fifth ring and the sixth ring contributed the most. (3) through scenarios analysis, for further reducing the emission from concrete batching in 2020, more stricter standard for green production as well as powerful supervision is needed.

  17. Fed-batch versus batch cultures of Yarrowia lipolytica for γ-decalactone production from methyl ricinoleate.

    Science.gov (United States)

    Gomes, Nelma; Teixeira, José A; Belo, Isabel

    2012-04-01

    Constant medium feeding rate and intermittent fed-batch fermentation strategies were investigated aiming to increase the yields of γ-decalactone production by Yarrowia lipolytica, using methyl ricinoleate as substrate and ricinoleic acid source. The accumulation of another compound, 3-hydroxy-γ-decalactone, was also analyzed since it derives from the direct precursor of γ-decalactone thereby providing information about the enzymatic activities of the pathway. Both strategies were compared with the traditional batch mode in terms of overall productivity and yield in respect to the substrate. Although the productivity of γ-decalactone was considerably higher in the batch mode (168 mg l(-1) h(-1)), substrate conversion to lactone (73 mg γ-decalactone g(-1)) was greater in the intermittent fed-batch giving 6.8 g γ-decalactone l(-1). This last strategy therefore has potential for γ-decalactone production at an industrial level.

  18. Batch and High Cell Density Fed-Batch Culture Productions of an Organophosphorus Hydrolase

    Science.gov (United States)

    2002-01-01

    0.02 g H3BO3, 0.01 g NaMoO4@ 2H2O , and 0.01 g CuSO4 . Fed-Batch Fermentations were carried out in the same Bio-Flow 3000 unit fitted with 10 L...per L): 3.0 g nitrilotriacetic acid, 6.0 MgSO4@7H2O, 1.0 g NaCl, 1.0 g MnSO4@H2O, 0.5 g FeSO4@7H20, 0.1 CaCl2@ 2H2O , 0.1 CoCl2@6H2O, 0.1 g ZnSO4@7H2O

  19. SLUDGE BATCH 7B GLASS VARIABILITY STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Edwards, T.

    2011-10-25

    The Defense Waste Processing Facility (DWPF) is preparing to initiate processing Sludge Batch 7b (SB7b). In support of the upcoming processing, the Savannah River National Laboratory (SRNL) provided a recommendation to utilize Frits 418 with a 6% Na{sub 2}O addition (26 wt% Na{sub 2}O in sludge) and 702 with a 4% Na{sub 2}O addition (24 wt% Na{sub 2}O in sludge) to process SB7b. This recommendation was based on assessments of the compositional projections for SB7b available at the time from the Savannah River Remediation (SRR). To support qualification of SB7b, SRNL executed a variability study to assess the applicability of the current durability models for SB7b. The durability models were assessed over the expected composition range of SB7b, including potential caustic additions, combined with Frits 702 and 418 over a 32-40% waste loading (WL) range. Thirty four glasses were selected based on Frits 418 and 702 coupled with the sludge projections with an additional 4-6% Na{sub 2}O to reflect the potential caustic addition. Six of these glasses, based on average nominal sludge compositions including the appropriate caustic addition, were developed for both Frit 418 and Frit 702 at 32, 36 and 40% WL to provide coverage in the center of the anticipated SB7b glass region. All glasses were fabricated and characterized using chemical composition analysis, X-ray diffraction (XRD) and the Product Consistency Test (PCT). To comply with the DWPF Glass Product Control Program, a total of thirty four glasses were fabricated to assess the applicability of the current DWPF PCCS durability models. Based on the measured PCT response, all of the glasses were acceptable with respect to the Environmental Assessment (EA) benchmark glass regardless of thermal history. The NL[B] values of the SB7b variability study glasses were less than 1.99 g/L as compared to 16.695 g/L for EA. A small number of the D-optimally selected 'outer layer' extreme vertices (EV) glasses were not

  20. SLUDGE BATCH VARIABILITY STUDY WITH FRIT 418

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Edwards, T.

    2010-11-29

    The Defense Waste Processing Facility (DWPF) initiated processing Sludge Batch 6 (SB6) in the summer of 2010. In support of processing, the Savannah River National Laboratory (SRNL) provided a recommendation to utilize Frit 418 to process SB6. This recommendation was based on assessments of the compositional projections for SB6 available at the time from the Liquid Waste Organization (LWO) and SRNL (using a model-based approach). To support qualification of SB6, SRNL executed a variability study to assess the applicability of the current durability models for SB6. The durability models were assessed over the expected Frit 418-SB6 composition range. Seventeen glasses were selected for the variability study based on the sludge projections used in the frit recommendation. Five of the glasses are based on the centroid of the compositional region, spanning a waste loading (WL) range of 32 to 40%. The remaining twelve glasses are extreme vertices (EVs) of the sludge region of interest for SB6 combined with Frit 418 and are all at 36% WL. These glasses were fabricated and characterized using chemical composition analysis, X-ray diffraction (XRD) and the Product Consistency Test (PCT). After initiating the SB6 variability study, the measured composition of the SB6 Tank 51 qualification glass produced at the SRNL Shielded Cells Facility indicated that thorium was present in the glass at an appreciable concentration (1.03 wt%), which made it a reportable element for SB6. This concentration of ThO{sub 2} resulted in a second phase of experimental studies. Five glasses were formulated that were based on the centroid of the new sludge compositional region combined with Frit 418, spanning a WL range of 32 to 40%. These glasses were fabricated and characterized using chemical composition analysis and the PCT. Based on the measured PCT response, all of the glasses (with and without thorium) were acceptable with respect to the Environmental Assessment (EA) reference glass