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

NASA Astrophysics Data System (ADS)

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

Research on the Microstructures and Mechanical Properties of Ti Micro-Alloyed Cold Rolled Hot-Dip Galvanizing DP980 Steel

NASA Astrophysics Data System (ADS)

Han, Yun; Kuang, Shuang; Qi, Xiumei; Xie, Chunqian; Liu, Guanghui

Effects of galvanizing simulation parameters on microstructures and mechanical properties of Ti-microalloyed cold rolled hot-dip galvanizing DP980 steel were investigated in this study by optical microscopy (OM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and tensile test. Moreover, the precipitation behavior of Ti in the experimental steel was also studied. The results show that, as the heating temperature increases, the tensile strength of experimental galvanizing DP980 steel decreases while the yield ratio and elongation of the steel are enhanced. The microstructures of experimental steels exhibit typical dual phase steel character and the volume fractions of MA islands are almost 30%. In addition, lots of nano-sized TiC precipitates can be found in the ferrite grains.

A novel method of utilization of hot dip galvanizing slag using the heat waste from itself for protection from radiation.

PubMed

Dong, Mengge; Xue, Xiangxin; Kumar, Ashok; Yang, He; Sayyed, M I; Liu, Shan; Bu, Erjun

2018-02-15

A novel, unconventional, low cost, eco-friendly and effective shielding materials have been made utilizing the hot dip galvanizing slag using the heat waste from itself, thereby saving the natural resources and preventing the environmental pollution. SEM-EDS of shielding materials indicates that the other elements are distributed in Zn element. The mass attenuation properties of shielding materials were measured using a narrow beam geometrical setup at 0.662MeV, 1.17MeV and 1.33MeV. The half value thickness layer, effective atomic number, and electron density were used to analyze the shielding performance of the materials. The EBFs and EABFs for the prepared shielding materials were also studied with incident photon energy for penetration depths upto 40mfp. The shielding effectiveness has been compared with lead, iron, zinc, some standard shielding concretes, different glasses and some alloys. The shielding effectiveness of the prepared samples is almost found comparable to iron, zinc, selected alloys and glasses while better than some standard shielding concretes. In addition, it is also found that the bending strength of all shielding materials is more than 110MPa. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Annealing Temperature on Microstructure and Mechanical Properties of Hot-Dip Galvanizing DP600 Steel

NASA Astrophysics Data System (ADS)

Hai-yan, Sun; Zhi-li, Liu; Yang, Xu; Jian-qiang, Shi; Lian-xuan, Wang

Hot-dip galvanizing dual phase steel DP600 steel grade with low Si was produced by steel plant and experiments by simulating galvanizing thermal history. The microstructure was observed and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of different annealing temperatures on the microstructure and mechanical properties of dual-phase steel was also discussed. The experimental results show that the dual-phase steel possesses excellent strength and elongation that match EN10346 600MPa standards. The microstructure is ferrite and martensite. TEM micrograph shows that white ferrite with black martensite islands inlay with a diameter of around 1um and the content of 14 18%. The volume will expand and phase changing take the form of shear transformation when ferrite converted to martensite. So there are high density dislocations in ferrite crystalline grain near martensite. The martensite content growing will be obvious along with annealing temperature going up. But the tendency will be weak when temperature high.

Evaluation of zinc coating procedures : final report.

DOT National Transportation Integrated Search

1978-01-01

This research project was conducted in order to compare the existing procedure of zinc coating by hot-dip galvanizing with the other zinc coating systems of painting and electroplating. : Hardware coated by these processes was exposed to varied labor...

Effect of Mg on the Microstructure and Corrosion Resistance of the Continuously Hot-Dip Galvanizing Zn-Mg Coating

PubMed Central

Dong, Anping; Li, Baoping; Lu, Yanling; Zhu, Guoliang; Xing, Hui; Shu, Da; Sun, Baode; Wang, Jun

2017-01-01

The microstructure of continuously hot-dip galvanizing Zn-Mg coating was investigated in order to obtain the mechanism of the effects of Mg on the corrosion resistance. In this paper, the vertical section of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner was calculated. The results indicates that the phase composition of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner is the same as Zn-Mg binary phase diagram, suggesting Al in the Zn-Mg (ZM) coatings mainly concentrates on the interfacial layer between the coating and steel substrate. The microstructure of continuously hot-dip galvanizing ZM coatings with 0.20 wt % Al containing 1.0–3.0 wt % Mg was investigated using tunneling electron microscopy (TEM). The morphology of Zn in the coating changes from bulk to strip and finally to mesh-like, and the MgZn2 changes from rod-like to mesh-like with the Mg content increasing. Al in the ZM coatings mainly segregates at the Fe2Al5 inhibition layer and the Mg added to the Zn bath makes this inhibition layer thinner and uneven. Compared to GI coating, the time of the first red rust appears increases by more than two-fold and expansion rate of red rust reduces by more than four-fold in terms of salt spray experiment. The ZM coating containing 2.0 wt % Mg has the best corrosion resistance. The enhanced corrosion resistance of ZM coatings mainly depends on different corrosion products. PMID:28829393

Effect of Mg on the Microstructure and Corrosion Resistance of the Continuously Hot-Dip Galvanizing Zn-Mg Coating.

PubMed

Dong, Anping; Li, Baoping; Lu, Yanling; Zhu, Guoliang; Xing, Hui; Shu, Da; Sun, Baode; Wang, Jun

2017-08-22

The microstructure of continuously hot-dip galvanizing Zn-Mg coating was investigated in order to obtain the mechanism of the effects of Mg on the corrosion resistance. In this paper, the vertical section of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner was calculated. The results indicates that the phase composition of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner is the same as Zn-Mg binary phase diagram, suggesting Al in the Zn-Mg (ZM) coatings mainly concentrates on the interfacial layer between the coating and steel substrate. The microstructure of continuously hot-dip galvanizing ZM coatings with 0.20 wt % Al containing 1.0-3.0 wt % Mg was investigated using tunneling electron microscopy (TEM). The morphology of Zn in the coating changes from bulk to strip and finally to mesh-like, and the MgZn₂ changes from rod-like to mesh-like with the Mg content increasing. Al in the ZM coatings mainly segregates at the Fe₂Al₅ inhibition layer and the Mg added to the Zn bath makes this inhibition layer thinner and uneven. Compared to GI coating, the time of the first red rust appears increases by more than two-fold and expansion rate of red rust reduces by more than four-fold in terms of salt spray experiment. The ZM coating containing 2.0 wt % Mg has the best corrosion resistance. The enhanced corrosion resistance of ZM coatings mainly depends on different corrosion products.

Simulation to coating weight control for galvanizing

NASA Astrophysics Data System (ADS)

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

2013-05-01

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

Theoretical Investigation of the Interfacial Reactions during Hot-Dip Galvanizing of Steel

NASA Astrophysics Data System (ADS)

Mandal, G. K.; Balasubramaniam, R.; Mehrotra, S. P.

2009-03-01

In the modern galvanizing line, as soon as the steel strip enters the aluminum-containing zinc bath, two reactions occur at the strip and the liquid-zinc alloy interface: (1) iron rapidly dissolves from the strip surface, raising the iron concentration in the liquid phase at the strip-liquid interface; and (2) aluminum forms a stable aluminum-iron intermetallic compound layer at the strip-coating interface due to its greater affinity toward iron. The main objective of this study is to develop a simple and realistic mathematical model for better understanding of the kinetics of galvanizing reactions at the strip and the liquid-zinc alloy interface. In the present study, a model is proposed to simulate the effect of various process parameters on iron dissolution in the bath, as well as, aluminum-rich inhibition layer formation at the substrate-coating interface. The transient-temperature profile of the immersed strip is predicted based on conductive and convective heat-transfer mechanisms. The inhibition-layer thickness at the substrate-coating interface is predicted by assuming the cooling path of the immersed strip consists of a series of isothermal holds of infinitesimal time-step. The influence of galvanizing reaction is assessed by considering nucleation and growth mechanisms at each hold time, which is used to estimate the total effect of the immersion time on the formation mechanism of the inhibition layer. The iron- dissolution model is developed based on well established principles of diffusion taking into consideration the area fraction covered by the intermetallic on the strip surface during formation of the inhibition layer. The model can be effectively used to monitor the dross formation in the bath by optimizing the process parameters. Theoretical predictions are compared with the findings of other researchers. Simulated results are in good agreement with the theoretical and experimental observation carried out by other investigators.

Effect of Process Parameters on the Structure and Properties of Galvanized Sheets

NASA Astrophysics Data System (ADS)

Shukla, S. K.; Saha, B. B.; Triathi, B. D.; Avtar, Ram

2010-07-01

The effect of galvanizing parameters on the structure (spangle size and coating microstructure) and properties (formability and corrosion resistance) of galvanized sheets was studied in a hot dip process simulator (HDPS) in a conventional Pb bearing (0.08-0.10%) zinc bath by varying zinc bath Al level (0.10-0.28%), bath temperature (718-743 K), dipping time (1.5-3.5 s), wiping gas flow rate (200-450 lpm), nozzle distance (15-17 mm) and wiping delay time (0.1-2.1 s). Al level in the range of 0.18-0.24% in combination with dipping time of 1.5-2.5 s and bath temperature of 718-733 K results in superior formability ( E cv: ~9.3 mm) of the composite (thickness: 0.8 mm). High post-dip cooling rates (~25 K/s) suppress spangle growth (spangle size: ~2 mm). The spangle size of the GI sheet strongly influences the corrosion rate which increases from 5.8 to 9.2 mpy with a decrease in spangle size from 17.5 to 3 mm. By controlling the Al level (0.20%) in zinc bath and bath temperature (733 K), the corrosion rate of mini-spangle GI sheet can be controlled to a level of 5.5 mpy.

Vanadium Microalloyed High Strength Martensitic Steel Sheet for Hot-Dip Coating

NASA Astrophysics Data System (ADS)

Hutchinson, Bevis; Komenda, Jacek; Martin, David

Cold rolled steels with various vanadium and nitrogen levels have been treated to simulate the application of galvanizing and galvannealing to hardened martensitic microstructures. Strength levels were raised 100-150MPa by alloying with vanadium, which mitigates the effect of tempering. This opens the way for new ultra-high strength steels with corrosion resistant coatings produced by hot dip galvanising.

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

NASA Astrophysics Data System (ADS)

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

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

PubMed

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.

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

PubMed

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor.

PubMed

Ren, Xiulian; Wei, Qifeng; Hu, Surong; Wei, Sijie

2010-09-15

This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with omega(1/2) (omega: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH(4)Cl concentration was 53.46 g L(-1) and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min(-1). Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor. Copyright 2010 Elsevier B.V. All rights reserved.

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials

PubMed Central

Azari, Z.; 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. PMID:27347531

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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 < 0.3) oxides. The addition of the minor alloying elements changed the morphology of the Si-rich oxides from a continuous film to discrete islands and this improved the wettability by molten Zn. The improved wetting effect of the minor alloying elements was attributed to an increased area fraction of the surface where the oxides were thinner, enabling a direct unhindered reaction between Fe and the Al in the liquid Zn and the 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.

A study of the influence of air-knife tilting on coating thickness in hot-dip galvanizing

NASA Astrophysics Data System (ADS)

Cho, Tae-Seok; Kwon, Young-Doo; Kwon, Soon-Bum

2009-09-01

Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5° is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pressure itself is not so large.

Comparative life cycle cost assessment of painted and hot-dip galvanized bridges.

PubMed

Rossi, B; Marquart, S; Rossi, G

2017-07-15

The study addresses the life cycle cost assessment (LCCA) of steel bridges, focusing on the maintenance activities and the maintenance scenario. Firstly, the unit costs of maintenance activities and their durability (i.e. the time between two activities) are evaluated. Pragmatic data are provided for the environment category C4 and for three activities: Patch Up, Overcoating and Remove & Replace. A comparative LCCA for a typical hypothetic steel girder bridge is carried out, either painted or hot-dip galvanized (HDG), in the environmental class C4. The LCC versus the cumulated life is provided for both options. The initial cost of the steel unpainted option is only 50.3% of the HDG option. It is shown that after 'Overcoating' occurring at 18.5 years, the total Net Present Value (NPV) of the painted option surpasses that of the HDG option. A sensitivity analysis of the NPV to the cost and service life parameters, the escalation and discount rates is then performed. The discount and escalation rates, considerably influences the total LCC, following a non-linear trend. The total LCC decreases with the discount rate increasing and, conversely, increases with the escalation rate increasing. Secondly, the influence of the maintenance scenario on the total LCC is assessed based on a probabilistic approach. A permutation of the three independent maintenance activities assumed to occur six times over the life of the bridge is considered and a probability of occurrence is associated to each unique scenario. The most probable scenarios are then classified according to their NPV or achieved service life. This approach leads to the definition of a cost-effective maintenance scenario i.e. the scenario, within all the considered permutations, that has the minimum LCC in a range of lifespan. Besides, the probabilistic analysis also shows that, whatever the scenario, the return on investment period ranges between 18.5 years and 24.2 years. After that period, the HDG option becomes

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

PubMed Central

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

Respiratory Symptoms and Pulmonary Function Tests among Galvanized Workers Exposed To Zinc Oxide.

PubMed

Aminian, Omid; Zeinodin, Hamidreza; Sadeghniiat-Haghighi, Khosro; Izadi, Nazanin

2015-01-01

Galvanization is the process of coating steel or cast iron pieces with a thin layer of zinc allowing protection against corrosion. One of the important hazards in this industry is exposure to zinc compounds specially zinc oxide fumes and dusts. In this study, we evaluated chronic effects of zinc oxide on the respiratory tract of galvanizers. Overall, 188 workers were selected from Arak galvanization plant in 2012, 71 galvanizers as exposed group and 117 workers from other departments of plants as control group. Information was collected using American Thoracic Society (ATS) standard questionnaire, physical examination and demographic data sheet. Pulmonary function tests were measured for all subjects. Exposure assessment was done with NIOSH 7030 method. The Personal Breathing Zone (PBZ) air sampling results for zinc ranged from 6.61 to 8.25 mg/m³ above the permissible levels (Time weighted average; TWA:2 mg/m³). The prevalence of the respiratory symptoms such as dyspnea, throat and nose irritation in the exposed group was significantly (P<0.01) more than the control group. Decreasing in average percent in all spirometric parameters were seen in the galvanizers who exposed to zinc oxide fumes and dusts. The prevalence of obstructive respiratory disease was significantly (P=0.034) higher in the exposed group. High workplace zinc levels are associated with an increase in respiratory morbidity in galvanizers. Therefore administrators should evaluate these workers with periodic medical examinations and implement respiratory protection program in the working areas.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

PubMed

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.

40 CFR 420.121 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Hot Coating Subcategory § 420.121 Specialized definitions. (a) The term galvanizing means coating steel products with zinc by the hot dip... products with terne metal by the hot dip process including the immersion of the steel product in a molten...

40 CFR 420.121 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Hot Coating Subcategory § 420.121 Specialized definitions. (a) The term galvanizing means coating steel products with zinc by the hot dip... products with terne metal by the hot dip process including the immersion of the steel product in a molten...

40 CFR 420.121 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Hot Coating Subcategory § 420.121 Specialized definitions. (a) The term galvanizing means coating steel products with zinc by the hot dip... products with terne metal by the hot dip process including the immersion of the steel product in a molten...

Role of Al in Zn bath on the formation of the inhibition layer during hot-dip galvanizing for a 1.2Si-1.5Mn transformation-induced plasticity steel

NASA Astrophysics Data System (ADS)

Wang, Kuang-Kuo; Hsu, Chiung-Wen; Chang, Liuwen; Gan, Dershin; Yang, Kuo-Cheng

2013-11-01

This study investigated the interaction between the Al in the Zn bath and the surface oxides formed by selective oxidation on a 1.2Si-1.5Mn TRIP steel during hot-dip galvanizing. XPS and TEM were employed for characterization. The results indicated that the amorphous xMnO·SiO2 oxide could react with Al to form a Si-Mn-Al-containing oxide. The crystalline MnSiO3 and Mn2SiO4 oxides could be largely reduced by Al to form holes in the oxide film. Consequently, the steel covered by a layer of mixed xMnO·SiO2 and MnSiO3 could form a continuous Fe2Al5 inhibition layer and showed the highest galvanizability among the three samples examined.

Corrosion protection of galvanized steels by silane-based treatments

NASA Astrophysics Data System (ADS)

Yuan, Wei

The possibility of using silane coupling agents as replacements for chromate treatments was investigated on galvanized steel substrates. In order to understand the influence of deposition parameters on silane film formation, pure zinc substrates were first used as a model for galvanized steel to study the interaction between silane coupling agents and zinc surfaces. The silane films formed on pure zinc substrates from aqueous solutions were characterized by ellipsometry, contact angle measurements, reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. The deposition parameters studied include solution concentration, solution dipping time and pH value of the applied solution. It appears that silane film formation involved a true equilibrium of hydrolysis and condensation reactions in aqueous solutions. It has been found that the silane film thickness obtained depends primarily on the solution concentration and is almost independent of the solution dipping time. The molecular orientation of applied silane films is determined by the pH value of applied silane solutions and the isoelectric point of metal substrates. The deposition window in terms of pH value for zinc substrates is between 6.0 and 9.0. The total surface energy of the silane-coated pure zinc substrates decreases with film aging time, the decrease rate, however, is determined by the nature of silane coupling agents. Selected silane coupling agents were applied as prepaint or passivation treatments onto galvanized steel substrates. The corrosion protection provided by these silane-based treatments were evaluated by salt spray test, cyclic corrosion test, electrochemical impedance spectroscopy, and stack test. The results showed that silane coupling agents can possibly be used to replace chromates for corrosion control of galvanized steel substrates. Silane coatings provided by these silane treatments serve mainly as physical barriers. Factors that

Influence of Gas Atmosphere Dew Point on the Selective Oxidation and the Reactive Wetting During Hot Dip Galvanizing of CMnSi TRIP Steel

NASA Astrophysics Data System (ADS)

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

2013-01-01

The selective oxidation and reactive wetting of intercritically annealed Si-bearing CMnSi transformation-induced plasticity steels were investigated by high-resolution transmission electron microscopy. In a N2 + 10 pct H2 gas atmosphere with a dew point (DP) ranging from 213 K to 278 K (-60 °C to 5 °C), a continuous layer of selective oxides was formed on the surface. Annealing in a higher DP gas atmosphere resulted in a thinner layer of external oxidation and a greater depth of internal oxidation. The hot dipping was carried out in a Zn bath containing 0.22 mass pct Al, and the bath temperature was 733 K (460 °C). Coarse and discontinuous Fe2Al5- x Zn x grains and Fe-Zn intermetallics (ζ and δ) were observed at the steel/coating interface after the hot dip galvanizing (HDG) of panels were annealed in a low DP atmosphere 213 K (-60 °C). The Fe-Zn intermetallics were formed both in areas where the Fe2Al5- x Zn x inhibition layer had not been formed and on top of non-stoichiometric Fe-Al-Zn crystals. Poor wetting was observed on panels annealed in a low DP atmosphere because of the formation of thick film-type oxides on the surface. After annealing in higher DP gas atmospheres, i.e., 263 K and 278 K (-10 °C and 5 °C), a continuous and fine-grained Fe2Al5- x Zn x layer was formed. No Fe-Zn intermetallics were formed. The small grain size of the inhibition layer was attributed to the nucleation of the Fe2Al5- x Zn x grains on small ferrite sub-surface grains and the presence of granular surface oxides. A high DP atmosphere can therefore significantly contribute to the decrease of Zn-coating defects on CMnSi TRIP steels processed in HDG lines.

The Corrosion Behavior of Cold Sprayed Zinc Coatings on Mild Steel Substrate

NASA Astrophysics Data System (ADS)

Chavan, Naveen Manhar; Kiran, B.; Jyothirmayi, A.; Phani, P. Sudharshan; Sundararajan, G.

2013-04-01

Zinc and its alloy coatings have been used extensively for the cathodic protection of steel. Zinc coating corrodes in preference to the steel substrate due to its negative corrosion potential. Numerous studies have been conducted on the corrosion behavior of zinc and its alloy coatings deposited using several techniques viz., hot dip galvanizing, electrodeposition, metalizing or thermal spray etc. Cold spray is an emerging low temperature variant of thermal spray family which enables deposition of thick, dense, and pure coatings at a rapid rate with an added advantage of on-site coating of steel structures. In the present study, the corrosion characteristics of cold sprayed zinc coatings have been investigated for the first time. In addition, the influence of heat treatment of zinc coating at a temperature of 150 °C on its corrosion behavior has also been addressed.

Process for dezincing galvanized steel

DOEpatents

Morgan, W.A.; Dudek, F.J.; Daniels, E.J.

1998-07-14

A process is described for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75 C and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (1) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (2) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (3) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (4) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte. 1 fig.

Process for dezincing galvanized steel

DOEpatents

Morgan, William A.; Dudek, Frederick J.; Daniels, Edward J.

1998-01-01

A process for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75.degree. C. and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (i) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (ii) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (iii) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (iv) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte.

Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part II. Damage modes

NASA Astrophysics Data System (ADS)

Parisot, Rodolphe; Forest, Samuel; Pineau, André; Grillon, François; Demonet, Xavier; Mataigne, Jean-Michel

2004-03-01

Zinc-based coatings are widely used for protection against corrosion of steel-sheet products in the automotive industry. The objective of the present article is to investigate the damage modes at work in three different microstructures of a zinc coating on an interstitial-free steel substrate under tension, planestrain tension, and expansion loading. Plastic-deformation mechanisms are addressed in the companion article. Two main fracture mechanisms, namely, intergranular cracking and transgranular cleavage fracture, were identified in an untempered cold-rolled coating, a tempered cold-rolled coating, and a recrystallized coating. No fracture at the interface between the steel and zinc coating was observed that could lead to spalling, in the studied zinc alloy. A complex network of cleavage cracks and their interaction with deformation twinning is shown to develop in the material. An extensive quantitative analysis based on systematic image analysis provides the number and cumulative length of cleavage cracks at different strain levels for the three investigated microstructures and three loading conditions. Grain refinement by recrystallization is shown to lead to an improved cracking resistance of the coating. A model for crystallographic cleavage combining the stress component normal to the basal plane and the amount of plastic slip on the basal slip systems is proposed and identified from equibiaxial tension tests and electron backscattered diffraction (EBSD) analysis of the cracked grains. This analysis requires the computation of the nonlinear stress-strain response of each grain using a crystal-plasticity constitutive model. The model is then applied successfully to other loading conditions and is shown to account for the preferred orientations of damaged grains observed in the case of plane-strain tension.

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

NASA Astrophysics Data System (ADS)

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.

Hot-dipped tin-zinc on U-0. 75 w/o Ti

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weirick, L.J.

1979-09-01

Conventional Zn galvanizing of U-0.75 Ti results in nonuniform coatings and reduced elongation because of thermal aging of the surface of the U-Ti. A lower melting material which would give sacrificial galvanic protection to the U-Ti was found in the Sn-Zn alloy system. The present work describes: (1) the metallography of the Sn-Zn system, (2) the electrochemistry of the Sn-Zn system with respect to U-Ti, (3) the mechanics of applying a Sn-Zn coating to U-Ti, (4) salt spray corrosion test results of various Sn-Zn alloys applied to U-Ti coupons, and (5) mechanical property tests of coated U-Ti tensile bars. Anmore » 80 Sn-20 Zn alloy (MP-280/sup 0/C) was chosen for the galvanizing study because of its lower melting point. The results showed that all alloys of the Sn-Zn system galvanically protected the U-Ti in salt fog environments. The lack of a suitable low temperature flux prevented the operation of the Sn-Zn bath at its optimum temperature and low elongations were obtained with this coating system.« less

Remote Laser Welding of Zinc Coated Steel Sheets in an Edge Lap Configuration with Zero Gap

NASA Astrophysics Data System (ADS)

Roos, Christian; Schmidt, Michael

Remote Laser Welding (RLW) of zinc-coated steel sheets is a great challenge for the automotive industry but offers high potentials with respect to flexibility and costs. In state of the art applications, sheets are joined in overlap configuration with a preset gap for a stable zinc degassing. This paper investigates RLW of fillets without a preset gap and conditions for a stable process. The influence of process parameters on weld quality and process stability is shown. Experimental data give evidence, that the degassing of zinc through the capillary and the rear melt pool are the major degassing mechanisms. Furthermore the paper gives experimental validation of the zinc degassing in advance of the process zone to the open side of the fillet. Chemical analysis of the hot-dip galvanized zinc coating proof the iron-zinc-alloys to be the reason for a limited effectiveness of this mechanism in comparison to pure zinc as intermediate.

Comparative studies on acid leaching of zinc waste materials

NASA Astrophysics Data System (ADS)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

On the Processing of Martensitic Steels in Continuous Galvanizing Lines: Part 1

NASA Astrophysics Data System (ADS)

Song, Taejin; Kwak, Jaihyun; de Cooman, B. C.

2012-01-01

Whereas low-carbon (<0.2 mass pct) martensitic grades can be produced easily in continuous annealing processing lines equipped with the required cooling capacity, the thermal cycles in continuous galvanizing lines make it difficult to produce hot-dip Zn or Zn-alloy coated high-strength martensitic grades. This is because of the tempering processes occurring during dipping of the strip in the liquid Zn bath and, in the case of galvannealed sheet steel, the short thermal treatment required to achieve the alloying between the Zn and the steel. These short additional thermal treatments last less than 30 seconds but severely degrade the mechanical properties. Using a combination of internal friction, X-ray diffraction, and transmission electron microscopy, it is shown that the ultrafine-grained lath microstructure allows for a rapid dislocation recovery and carbide formation during the galvanizing processes. In addition, the effective dislocation pinning occurring during the galvannealing process results in strain localization and the suppression of strain hardening.

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

NASA Astrophysics Data System (ADS)

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.

Influence of Bond Coats on the Microstructure and Mechanical Behaviors of HVOF-Deposited TiAlNb Coatings

NASA Astrophysics Data System (ADS)

Zeng, H. J.; Zhang, L. Q.; Lin, J. P.; He, X. Y.; Zhang, Y. C.; Jia, P.

2012-12-01

Hot dip galvanizing has been extensively employed for corrosion protection of steel structures. However, during the process of galvanization, the corrosion in molten zinc brings many problems to galvanization industry. In this study, as a material of corrosion resistance to molten zinc intended for application in Hot-dip galvanization, HVOF Ti28.15Al63.4Nb8.25Y (at.%) coatings with different bond coats (NiCr5Al, NiCoCrAlY, CoCrAlYTaSi, and NiCr80/20) were deposited onto 316L stainless steel substrate, respectively. The influences of different bond coats on HVOF Ti28.15Al63.4Nb8.25Y coatings were investigated. The results showed that bond coat had an obvious influence on improving the mechanical properties of HVOF Ti28.15Al63.4Nb8.25Y coatings. HVOF Ti28.15Al63.4Nb8.25Y coatings with NiCoCrAlY bond coat displayed the best mechanical properties. However, bond coats had no obvious effects on the microstructure, porosity, and hardness of HVOF Ti28.15Al63.4Nb8.25Y top coatings. The effects of as-received powder morphology and grain size on the characteristics of coatings were also discussed.

Galvanizing and Galvannealing Behavior of CMnSiCr Dual-Phase Steels

NASA Astrophysics Data System (ADS)

Lin, Ko-Chun; Chu, Peng-Wei; Lin, Chao-Sung; Chen, Hon-Bor

2013-06-01

Alloying elements, such as Mn, Mo, Si, and Cr, are commonly used to enhance the strength of advanced high-strength steels. Those elements also play an important role in the hot-dip galvanizing (GI) and galvannealing (GA) process. In this study, two kinds of CMnSiCr dual-phase steels were galvanized and galvannealed using a hot-dip simulator to investigate the effect of the alloying elements on the microstructure of the GI and GA coatings. The results showed that the dual-phase steels had good galvanizability because no bare spots were observed and the Fe-Zn phases were readily formed at the interface. However, the alloying reaction during the GA process was significantly hindered. XPS analysis showed that external oxidation occurred under an extremely low dew point [213 K to 203 K (-60 °C to -70 °C)] atmosphere during the annealing prior to hot dipping. However, most of the oxides were reduced during the GI process. After the GI process, the Al was present as solid solutes in the Fe-Zn phase, suggesting that the Fe-Zn phase was formed from the transformation of the Fe-Al inhibition alloy. Meanwhile, the solubility of Si in the ζ phase was extremely low. With continued GA reaction, the ζ phase transformed into the δ phase, which contained approximately 1.0 at.pct Si. The Si also diffused into the Zn layer during the GA reaction. Hence, the ζ phase did not homogeneously nucleate at the steel substrate/Zn coating interface, but was found at the area away from the interface. Therefore, the Fe-Zn phases on the CMnSiCr dual-phase steels were relatively non-uniform compared to those on interstitial-free steel.

High Temperature Oxidation of Hot-Dip Aluminized T92 Steels

NASA Astrophysics Data System (ADS)

Abro, Muhammad Ali; Hahn, Junhee; Lee, Dong Bok

2018-03-01

The T92 steel plate was hot-dip aluminized, and oxidized in order to characterize the high-temperature oxidation behavior of hot-dip aluminized T92 steel. The coating consisted of Al-rich topcoat with scattered Al3Fe grains, Al3Fe-rich upper alloy layer with scattered (Al, Al5Fe2, AlFe)-grains, and Al5Fe2-rich lower alloy layer with scattered (Al5Fe2, AlFe)-grains. Oxidation at 800 °C for 20 h formed (α-Al2O3 scale)/(AlFe layer)/(AlFe3 layer)/(α-Fe(Al) layer), while oxidation at 900 °C for 20 h formed (α-Al2O3 scale plus some Fe2O3)/(AlFe layer)/(AlFe3 layer)/(α-Fe(Al) layer) from the surface. During oxidation, outward migration of all substrate elements, inward diffusion of oxygen, and back and forth diffusion of Al occurred according to concentration gradients. Also, diffusion transformed and broadened AlFe and AlFe3 layers dissolved with some oxygen and substrate alloying elements. Hot-dip aluminizing improved the high-temperature oxidation resistance of T92 steel through preferential oxidation of Al at the surface.

High Temperature Oxidation of Hot-Dip Aluminized T92 Steels

NASA Astrophysics Data System (ADS)

Abro, Muhammad Ali; Hahn, Junhee; Lee, Dong Bok

2018-05-01

The T92 steel plate was hot-dip aluminized, and oxidized in order to characterize the high-temperature oxidation behavior of hot-dip aluminized T92 steel. The coating consisted of Al-rich topcoat with scattered Al3Fe grains, Al3Fe-rich upper alloy layer with scattered (Al, Al5Fe2, AlFe)-grains, and Al5Fe2-rich lower alloy layer with scattered (Al5Fe2, AlFe)-grains. Oxidation at 800 °C for 20 h formed (α-Al2O3 scale)/(AlFe layer)/(AlFe3 layer)/(α-Fe(Al) layer), while oxidation at 900 °C for 20 h formed (α-Al2O3 scale plus some Fe2O3)/(AlFe layer)/(AlFe3 layer)/(α-Fe(Al) layer) from the surface. During oxidation, outward migration of all substrate elements, inward diffusion of oxygen, and back and forth diffusion of Al occurred according to concentration gradients. Also, diffusion transformed and broadened AlFe and AlFe3 layers dissolved with some oxygen and substrate alloying elements. Hot-dip aluminizing improved the high-temperature oxidation resistance of T92 steel through preferential oxidation of Al at the surface.

Selective Oxidation and Reactive Wetting During Hot-Dip Galvanizing of a 1.0 pct Al-0.5 pct Si TRIP-Assisted Steel

NASA Astrophysics Data System (ADS)

Bellhouse, E. M.; McDermid, J. R.

2012-07-01

Selective oxidation and reactive wetting during continuous galvanizing were studied for a low-alloy transformation induced plasticity (TRIP)-assisted steel with 0.2 pct C, 1.5 pct Mn, 1.0 pct Al and 0.5 pct Si. Three process atmospheres were tested during annealing prior to galvanizing: 220 K (-53 °C) dew point (dp) N2-20 pct H2, 243 K (-30 °C) dp N2-5 pct H2 and 278 K (+5 °C) dp N2-5 pct H2. The process atmosphere oxygen partial pressure affected the oxide chemistry, morphology and thickness. For the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres, film and nodule-type manganese, silicon and aluminum containing oxides were observed at the surface. For the 278 K (+5 °C) dp atmosphere, MnO was observed at the grain boundaries and as thicker localized surface films. Oxide morphology, thickness and chemistry affected reactive wetting, with complete wetting being observed for the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres and incomplete reactive wetting being observed for the 278 K (+5 °C) dp atmosphere. Complete reactive wetting for the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres was attributed to a combination of zinc bridging of oxides, aluminothermic reduction of surface oxides and wetting of the oxides. Incomplete wetting for the 278 K (+5 °C) dp atmosphere was attributed to localized thick MnO films.

The effect of zinc thickness on corrosion film breakdown of Colombian galvanized steel

NASA Astrophysics Data System (ADS)

Sandoval-Amador, A.; E Torres Ramirez, J.; Cabrales-Villamizar, P. A.; Laverde Cataño, D.; Y Peña-Ballesteros, D.

2017-12-01

This work studies the corrosion behaviour of Colombian galvanized steel in solutions of chloride and sulphate ions. The effect of the thickness and exposure time on the film’s breakdown susceptibility and protectiveness of the corrosion products were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The corrosion products were analysed using SEM-EDS and XRD. The samples with a higher thickness level in the zinc film (Z180) have the lowest corrosion rate. In this case, one of the products that was formed by the chemical reactions that occurred was Zinc hydroxide, which exhibits a passive behaviour as observed in the Pourbaix curves of the obtained potentials and in how the different Ph levels of the solutions worked. The sheets with the highest thickness (Z180) had the best performance, since at the end of the study they showed the least amount of damage on the surface of the zinc layer. This is because the thickness of the zinc layer favours the formation of simonkolleite, which is the corrosion product that protects the material under the conditions of the study.

A Cellular Automaton / Finite Element model for predicting grain texture development in galvanized coatings

NASA Astrophysics Data System (ADS)

Guillemot, G.; Avettand-Fènoël, M.-N.; Iosta, A.; Foct, J.

2011-01-01

Hot-dipping galvanizing process is a widely used and efficient way to protect steel from corrosion. We propose to master the microstructure of zinc grains by investigating the relevant process parameters. In order to improve the texture of this coating, we model grain nucleation and growth processes and simulate the zinc solid phase development. A coupling scheme model has been applied with this aim. This model improves a previous two-dimensional model of the solidification process. It couples a cellular automaton (CA) approach and a finite element (FE) method. CA grid and FE mesh are superimposed on the same domain. The grain development is simulated at the micro-scale based on the CA grid. A nucleation law is defined using a Gaussian probability and a random set of nucleating cells. A crystallographic orientation is defined for each one with a choice of Euler's angle (Ψ,θ,φ). A small growing shape is then associated to each cell in the mushy domain and a dendrite tip kinetics is defined using the model of Kurz [2]. The six directions of basal plane and the two perpendicular directions develop in each mushy cell. During each time step, cell temperature and solid fraction are then determined at micro-scale using the enthalpy conservation relation and variations are reassigned at macro-scale. This coupling scheme model enables to simulate the three-dimensional growing kinetics of the zinc grain in a two-dimensional approach. Grain structure evolutions for various cooling times have been simulated. Final grain structure has been compared to EBSD measurements. We show that the preferentially growth of dendrite arms in the basal plane of zinc grains is correctly predicted. The described coupling scheme model could be applied for simulated other product or manufacturing processes. It constitutes an approach gathering both micro and macro scale models.

How Many Atomic Layers of Zinc Are in a Galvanized Iron Coating? An Experiment for General Chemistry Laboratory

ERIC Educational Resources Information Center

Yang, Shui-Ping

2007-01-01

This article describes an experiment using a novel gasometric assembly to determine the thickness and number of atomic layers of zinc coating on galvanized iron substrates. Students solved this problem through three stages. In the first stage, students were encouraged to find a suitable acidic concentration through the guided-inquiry approach. In…

Zinc exposure for female workers in a galvanizing plant in Northern Italy.

PubMed

Riccò, Matteo; Cattani, Silvia; Signorelli, Carlo

2018-01-01

Very little is known regarding the toxicokinetics of inhaled zinc, in particular in the case of female workers and for modern, low exposure settings. Our aim is to evaluate the relationship of external zinc levels to those of serum and urine for female workers. Eleven female workers (age: 41.7±8 years old, body mass index (BMI): 23.5±4.2 kg/m²) in a galvanizing plant were investigated. Exposure assessment consisted of personal/environmental air samples, and measurement of zinc in serum (collected at the end of first shift of the working week (T1)) and urine, collected before the first shift of the working week (T0), T1 and at the end of the last shift of the working week (T2). Both environmental and personal air samplings for zinc and zinc compounds were below the recommended by the German Research Foundation (Deutsche Forschungsgemeinschaft - DFG) limit values of 2 mg/m³ (7.34±2.8 μg/m³ and 8.31±2.4 μg/ m³, respectively). Serum (118.6±20.9 μg /dl) and urine zinc levels were within reference values for female Italian subjects: the latter increased from 56.4±33.5 μg/dl at T0, to 59.8±37.0 μg/dl at T1, and ultimately 65.4±34.4 μg/dl at T2, but no significant trend was found. End of shift (Spearman's correlation coefficient p value = 0.027) and differential excretion of urinary zinc (both: T0 vs. T1 and T0 vs. T2) were correlated with airborne zinc concentration (p = 0.002 and 0.006, respectively). In general, our data suggests that urine may be a useful medium also for female in order to assess zinc exposure. Further studies are required in order to evaluate whether differential excretion may be useful for the biomonitoring of zinc exposure in the workplaces also for male workers. Int J Occup Med Environ Health 2018;31(1):113-124. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

On the Processing of Martensitic Steels in Continuous Galvanizing Lines: Part II

NASA Astrophysics Data System (ADS)

Song, Taejin; Kwak, Jaihyun; de Cooman, B. C.

2012-01-01

The conventional continuous hot-dip galvanizing (GI) and galvannealing (GA) processes can be applied to untransformed austenite to produce Zn and Zn-alloy coated low-carbon ultra-high-strength martensitic steel provided specific alloying additions are made. The most suitable austenite decomposition behavior results from the combined addition of boron, Cr, and Mo, which results in a pronounced transformation bay during isothermal transformation. The occurrence of this transformation bay implies a considerable retardation of the austenite decomposition in the temperature range below the bay, which is close to the stages in the continuous galvanizing line (CGL) thermal cycle related to the GI and GA processes. After the GI and GA processes, a small amount of granular bainite, which consists of bainitic ferrite and discrete islands of martensite/austenite (M/A) constituents embedded in martensite matrix, is present in the microstructure. The ultimate tensile strength (UTS) of the steel after the GI and GA cycle was over 1300 MPa, and the stress-strain curve was continuous without any yielding phenomena.

Effect of Zinc Coatings on Joint Properties and Interfacial Reactions in Aluminum to Steel Ultrasonic Spot Welding

NASA Astrophysics Data System (ADS)

Haddadi, F.; Strong, D.; Prangnell, P. B.

2012-03-01

Dissimilar joining of aluminum to steel sheet in multimaterial automotive structures is an important potential application of ultrasonic spot welding (USW). Here, the weldability of different zinc-coated steels with aluminum is discussed, using a 2.5-kW USW welder. Results show that soft hot-dipped zinc (DX56-Z)-coated steel results in better weld performance than hard (galv-annealed) zinc coatings (DX53-ZF). For Al to hard galv-annealed-coated steel welds, lap shear strengths reached a maximum of ~80% of the strength of an Al-Al joint after a 1.0 s welding time. In comparison, welds between Al6111-T4 and hot dipped soft zinc-coated steel took longer to achieve the same maximum strength, but nearly matched the Al-Al joint properties. The reasons for these different behaviors are discussed in terms of the interfacial reactions between the weld members.

Polyfibroblast: A Self-Healing and Galvanic Protection Additive

DTIC Science & Technology

2012-09-12

self-healing and galvanic protection capacity to the primer (Figure 1). Polyfibroblast consists of paint-filled microcapsules and zinc powder. It has...significant added cost. Microcapsule Figure 1. Polyfibroblast contains fresh paint encapsulated in polymer shells plus Zn powder. When scratched, resin...from the broken microcapsules fills the crack to form a polymer scar. Zn powder supplies galvanic protection in the event of incomplete healing

Research on Forming Mechanisms and Controlling Measurements for Surface Light Spot Defects of Galvanizing Steel Coils for Automobile Use

NASA Astrophysics Data System (ADS)

Guangmin, Wei; Haiyan, Sun; Jianqiang, Shi; Lianxuan, Wang; Haihong, Wu

When producing high surface quality galvanizing steel coils for automobile use, there are always many light spots on the surface since Hansteel CGL No.1 has been put into operation. The defect samples were analyzed by SEM and EDS. The result shows that cause for light spot is not only one. There are more Mn and P in high strength auto sheet, which can result in difficulty to be cleaned off the oxide on the hot rolled coils, so the defects coming. This is why the defects come with high strength auto sheet. When coils galvanized, the defects can't be covered up. To the contrary, the defects will be more obvious when zinc growing on the surface. And sometimes zinc or residue can adhere to work rolls when strips passing through SPM. The deposits then press normal coating. So the light spots come more. When the defect comes from pressing, there is no defect on steel base. The causation is found and measures were taken including high pressure cleaning equipments adopted. Result shows that the defects disappeared.

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

NASA Astrophysics Data System (ADS)

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.

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

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 11 2012-01-01 2012-01-01 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, 1990...

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

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 11 2014-01-01 2014-01-01 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, 1990...

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

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 11 2013-01-01 2013-01-01 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, 1990...

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

ERIC Educational Resources Information Center

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.…

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

NASA Astrophysics Data System (ADS)

Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

46 CFR 160.035-3 - Construction of steel oar-propelled lifeboats.

Code of Federal Regulations, 2010 CFR

2010-10-01

... apparatus shall have a minimum factor of safety of six. (2) For construction and capacity of disengaging... shall be galvanized by the hot dipped process. All fabricated pieces or sections are to be galvanized...

[Exposure to metal compounds in occupational galvanic processes].

PubMed

Surgiewicz, Jolanta; Domański, Wojciech

2006-01-01

Occupational galvanic processes are provided in more than 600 small and medium enterprises in Poland. Workers who deal with galvanic coating are exposed to heavy metal compounds: tin, silver, copper and zinc. Some of them are carcinogenic, for example, hexavalent chromium compounds, nickel and cadmium compounds. Research covered several tens of workstations involved in chrome, nickel, zinc, tin, silver, copper and cadmium plating. Compounds of metals present in the air were determined: Cr, Ni, Cd, Sn, Ag--by atomic absorption spectrometry with electrothermal atomization (ET-AAS) and Zn--by atomic absorption spectrometry with flame atomization (F-AAS). The biggest metal concentrations--of silver and copper--were found at workstations of copper, brass, cadmium, nickel and chrome plating, conducted at the same time. Significant concentrations of copper were found at workstations of maintenance bathing and neutralizing of sewage. The concentrations of metals did not exceed Polish MAC values. MAC values were not exceeded for carcinogenic chromium(VI), nickel or cadmium, either. In galvanic processes there was no hazard related to single metals or their compounds, even carcinogenic ones. Combined exposure indicators for metals at each workstation did not exceed 1, either. However, if there are even small quantities of carcinogenic agents, health results should always be taken into consideration.

Interfacial chemistry of zinc anodes for reinforced concrete structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Covino, B.S. Jr.; Bullard, S.J.; Cramer, S.D.

1997-12-01

Thermally-sprayed zinc anodes are used in both galvanic and impressed current cathodic protection systems for reinforced concrete structures. The Albany Research Center, in collaboration with the Oregon Department of Transportation, has been studying the effect of electrochemical aging on the bond strength of zinc anodes for bridge cathodic protection systems. Changes in anode bond strength and other anode properties can be explained by the chemistry of the zinc-concrete interface. The chemistry of the zinc-concrete interface in laboratory electrochemical aging studies is compared with that of several bridges with thermal-sprayed zinc anodes and which have been in service for 5 tomore » 10 years using both galvanic and impressed current cathodic protection systems. The bridges are the Cape Creek Bridge on the Oregon coast and the East Camino Undercrossing near Placerville, CA. Also reported are interfacial chemistry results for galvanized steel rebar from the 48 year old Longbird Bridge in Bermuda.« less

Techno-Economic Assessment of Recycling BOF Offgas Cleaning System Solid Wastes by Using Zinc-Free Scrap

NASA Astrophysics Data System (ADS)

Ma, Naiyang

High zinc concentration in basic oxygen furnace (BOF) steelmaking offgas (OG) cleaning system solid wastes is one of the main barriers for recycling of the solid wastes in sintering — blast furnace ironmaking process. One of the possible solutions is to utilize zinc-free scrap in BOF steelmaking so that the BOF OG solid wastes will not be contaminated with zinc and can be recycled through sintering — blast furnace ironmaking. This paper describes a model for helping to decide whether to use zinc-free scrap in a BOF process. A model computing marginal price increment of zinc-free scrap is developed. The marginal price increment is proportional to value change of the BOF OG solid wastes after and before using zinc-free scrap, to ratio of BOF solid waste rate to purchased galvanized scrap rate, and to price of galvanized scrap. Due to the variations of consumption rate of purchased galvanized scrap and home galvanized scrap, iron ore price, landfill cost, and price of purchased galvanized scrap, using zinc-free scrap in a BOF process might be economically feasible for some ironmaking and steelmaking plants or in some particular market circumstances.

Personal reflections on a galvanizing trail.

PubMed

O'Dell, B L

1998-01-01

This article encompasses my perception of, and experience in, an exciting segment of the trace element era in nutrition research: the role of zinc in the nutrition of animals and humans. Zinc has been a major player on the stage of trace element research, and it has left a trail that galvanized the attention of many researchers, including myself. It is ubiquitous in biological systems, and it plays a multitude of physiologic and biochemical functions. A brief historical overview is followed by a discussion of the contributions the work done in my laboratory has made toward understanding the physiological and biochemical functions of zinc. The effort of 40 years has led to the belief that one of zinc's major roles, and perhaps its first limiting role, is to preserve plasma-membrane function as regards ion channels and signal transduction. Although substantial knowledge has been gained relating to the importance of zinc in nutrition, much remains to be discovered.

The Corrosion Protection of 2219-T87 Aluminum by Organic and Inorganic Zinc-Rich Primers

NASA Technical Reports Server (NTRS)

Danford, M. D.; Mendrek, M. J.; Walsh, D. W.

1995-01-01

The behavior of zinc-rich primer-coated 2219-T87 aluminum in a 3.5-percent Na-Cl was investigated using electrochemical techniques. The alternating current (ac) method of electrochemical impedance spectroscopy (EIS), in the frequency range of 0.001 to 40,000 Hz, and the direct current (dc) method of polarization resistance (PR) were used to evaluate the characteristics of an organic, epoxy zinc-rich primer and an inorganic, ethyl silicate zinc-rich primer. A dc electrochemical galvanic corrosion test was also used to determine the corrosion current of each zinc-rich primer anode coupled to a 2219-T87 aluminum cathode. Duration of the EIS/PR and galvanic testing was 21 days and 24 h, respectively. The galvanic test results demonstrated a very high galvanic current between the aluminum cathode and both zinc-rich primer anodes (37.9 pA/CM2 and 23.7 pA/CM2 for the organic and inorganic primers, respectively). The PR results demonstrated a much higher corrosion rate of the zinc in the inorganic primer than in the organic primer, due primarily to the higher porosity in the former. Based on this investigation, the inorganic zinc-rich primer appears to provide superior galvanic protection and is recommended for additional study for application in the solid rocket booster aft skirt.

The corrosion protection of 2219-T87 aluminum by organic and inorganic zinc-rich primers

NASA Technical Reports Server (NTRS)

Danford, M. D.; Mendrek, M. J.; Walsh, D. W.

1995-01-01

The behavior of zinc-rich primer-coated 2219-T87 aluminum in a 3.5-percent Na-Cl was investigated using electrochemical techniques. The alternating current (ac) method of electro-chemical impedance spectroscopy (EIS), in the frequency range of 0.001 to 40,000 Hz, and the direct current (dc) method of polarization resistance (PR) were used to evaluate the characteristics of an organic, epoxy zinc-rich primer and an inorganic, ethyl silicate zinc-rich primer. A dc electrochemical galvanic corrosion test was also used to determine the corrosion current of each zinc-rich primer anode coupled to a 2219-T87 aluminum cathode. Duration of the EIS/PR and galvanic testing was 21 days and 24 h, respectively. the galvanic test results demonstrated a very high galvanic current between the aluminum cathode and both zinc-rich primer anodes (37.9 micro A/cm(exp 2) and 23.7 micro A/cm(exp 2) for the organic and inorganic primers, respectively). The PR results demonstrated a much higher corrosion rate of the zinc in the inorganic primer than in the organic primer, due primarily to the higher porosity in the former. Based on this investigation, the inorganic zinc-rich primer appears to provide superior galvanic protection and is recommended for additional study for application in the solid rocket booster aft skirt.

Performance of Inductors Attached to a Galvanizing Bath

NASA Astrophysics Data System (ADS)

Zhou, Xinping; Yuan, Shuo; Liu, Chi; Yang, Peng; Qian, Chaoqun; Song, Bao

2013-12-01

By taking a galvanizing bath with inductors from an Iron and Steel Co., Ltd as an example, the distributions of Lorentz force and generated heat in the inductor are simulated. As a result, the zinc flow and the temperature distribution driven by the Lorentz force and the generated heat in the inductor of a galvanizing bath are simulated numerically, and their characteristics are analyzed. The relationship of the surface-weighted average velocity at the outlet and the temperature difference between the inlet and the outlet and the effective power for the inductor is studied. Results show that with an increase in effective power for the inductor, the surface-weighted average velocity at the outlet and the temperature difference between the inlet and the outlet increase gradually. We envisage this work to lay a foundation for the study of the performance of the galvanizing bath in future.

Real-time monitoring of laser welding of galvanized high strength steel in lap joint configuration

NASA Astrophysics Data System (ADS)

Kong, Fanrong; Ma, Junjie; Carlson, Blair; Kovacevic, Radovan

2012-10-01

Two different cases regarding the zinc coating at the lap joint faying surface are selected for studying the influence of zinc vapor on the keyhole dynamics of the weld pool and the final welding quality. One case has the zinc coating fully removed at the faying surface; while the other case retains the zinc coating on the faying surface. It is found that removal of the zinc coating at the faying surface produces a significantly better weld quality as exemplified by a lack of spatters whereas intense spatters are present when the zinc coating is present at the faying surface. Spectroscopy is used to detect the optical spectra emitted from a laser generated plasma plume during the laser welding of galvanized high strength DP980 steel in a lap-joint configuration. A correlation between the electron temperature and defects within the weld bead is identified by using the Boltzmann plot method. The laser weld pool keyhole dynamic behavior affected by a high-pressure zinc vapor generated at the faying surface of galvanized steel lap-joint is monitored in real-time by a high speed charge-coupled device (CCD) camera assisted with a green laser as an illumination source.

Dip-slope and Dip-slope Failures in Taiwan - a Review

NASA Astrophysics Data System (ADS)

Lee, C.

2011-12-01

Taiwan is famous for dip-slope and dip-slope slides. Dip-slopes exist at many places in the fold-and-thrust belt of Taiwan. Under active cutting of stream channels and man-made excavations, a dip-slope may become unstable and susceptible for mass sliding. Daylight of a bedding parallel clay seam is the most dangerous type for dip-slope sliding. Buckling or shear-off features may also happen at toe of a long dip-slope. Besides, a dip-slope is also dangerous for shallow debris slides, if the slope angle is between 25 to 45 degrees and the debris (colluvium or slope wash) is thick (>1m). These unstable slopes may slide during a triggering event, earthquake or typhoon storm; or even slide without a triggering event, like the 2010 Tapu case. Initial buckling feature had been found in the dip-slope of the Feitsui arch dam abutment after detailed explorations. Shear-off feature have also been found in dip-slope located in right bank of the Nahua reservoir after field investigation and drilling. The Chiufengerhshan slide may also be shear-off type. On the other hand, the Tapu, the Tsaoling slides and others are of direct slide type. The Neihoo Bishan slide is a shallow debris slide on dip-slope. All these cases demonstrate the four different types of dip-slope slide. The hazard of a dip-slope should be investigated to cover these possible types of failure. The existence of bedding parallel clay seams is critical for the stability of a dip-slope, either for direct slide or buckling or shear-off type of failure, and is a hot point during investigation. Because, the stability of a dip-slope is changing with time, therefore, detailed explorations to including weathering and erosion rates are also very necessary to ensure the long-term stability of a dip-slope.

Selective Oxidation and Reactive Wetting during Galvanizing of a CMnAl TRIP-Assisted Steel

NASA Astrophysics Data System (ADS)

Bellhouse, E. M.; McDermid, J. R.

2011-09-01

A transformation induced plasticity (TRIP)-assisted steel with 0.2 pct C, 1.5 pct Mn, and 1.5 pct Al was successfully galvanized using a thermal cycle previously shown to produce an excellent combination of strength and ductility. The steel surface chemistry and oxide morphology were determined as a function of process atmosphere oxygen partial pressure. For the 220 K (-53 °C) dew point (dp) + 20 pct H2 atmosphere, the oxide morphology was a mixture of films and nodules. For the 243 K (-30 °C) dp + 5 pct H2 atmosphere, nodules of MnO were found primarily at grain boundaries. For the 278 K (+5 °C) dp + 5 pct H2 atmosphere, nodules of metallic Fe were found on the surface as a result of alloy element internal oxidation. The steel surface chemistry and oxide morphology were then related to the reactive wetting behavior during continuous hot dip galvanizing. Good wetting was obtained using the two lower oxygen partial pressure process atmospheres [220 K dp and 243 K dp (-53 °C dp and -30 °C dp)]. An increase in the number of bare spots was observed when using the higher oxygen partial pressure process atmosphere (+5 °C dp) due to the increased thickness of localized oxide films.

Coating transformations in the early stages of hot-dip galvannealing of steel sheet

NASA Astrophysics Data System (ADS)

McDevitt, Erin Todd

The present, comprehensive study of the reactions occurring early in galvanneal processing under conditions typical of commercial production represents the first detailed investigation of the microstructural evolution of the coating in the early stages of galvannealing and the results shed new light on the course of the coating microstructural development. During hot dipping, an Fe2Al5 inhibition layer formed on the surface of the steel substrate in the first instants of immersion in Zn baths containing as low as 0.10 wt.% Al. When hot-dipping in a 0.14 wt.% Al, the as-dipped coating microstructure consisted of an Fe2Al 5 layer on the steel surface. That layer was covered by a layer of the Fe-Zn compound Gamma1, which was covered by the zeta phase or unalloyed Zn. Substrate chemistry did not affect coating microstructure development in the bath. Thermodynamic predictions of the precipitation behavior during the bath reactions agrees well with experimental observations. A mechanism for coating microstructure development in the Zn bath which is consistent with all the experimental results is proposed. From this information, the metallurgical variables which govern inhibition layer formation are discerned. The breakdown of the Fe2Al5 inhibition layer during galvannealing at 500°C occurred without the formation of outbursts. Instead, the grain boundary diffusion of Al into the steel substrate accounted for dissolution of the inhibition layer in the first second of galvannealing. A mechanism for inhibition layer breakdown is presented. P-additions affected only the rate at which the inhibition layer dissolved and did not affect the rate of Fe-Zn compound formation. P in the substrate blocked grain boundary diffusion of Al into the substrate thus slowing inhibition layer dissolution. The slower overall galvannealing behavior often observed on P-bearing substrates is due to a longer period of inhibition layer survival which results in a longer incubation period for the

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

NASA Astrophysics Data System (ADS)

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

2009-07-01

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

Surface Oxidation of the High-Strength Steels Electrodeposited with Cu or Fe and the Resultant Defect Formation in Their Coating during the Following Galvanizing and Galvannealing Processes

NASA Astrophysics Data System (ADS)

Choi, Yun-Il; Beom, Won-Jin; Park, Chan-Jin; Paik, Doojin; Hong, Moon-Hi

2010-12-01

This study examined the surface oxidation of high-strength steels electrodeposited with Cu or Fe and the resultant defect formation in their coating during the following galvanizing and galvannealing processes. The high-strength steels were coated with an Cu or Fe layer by the electroplating method. Then, the coated steels were annealed in a reducing atmosphere, dipped in a molten zinc, and finally transformed into galvannealed steels through the galvannealing process. The formation of Si and Mn oxides on the surface of the high-strength steel was effectively suppressed, and the density of surface defects on the galvanized steel was significantly reduced by the pre-electrodeposition of Cu and Fe. This effect was more prominent for the steels electrodeposited at higher cathodic current densities. The finer electrodeposit layer formed at higher cathodic current density on the steels enabled the suppression of partial surface oxidation by Mn or Si and better wetting of Zn on the surface of the steels in the following galvanizing process. Furthermore, the pre-electrodeposited steels exhibited a smoother surface without surface cracks after the galvannealing process compared with the untreated steel. The diffusion of Fe and Zn in the Zn coating layer in the pre-electrodeposited steels appears to occur more uniformly during the galvannealing process due to the low density of surface defects induced by oxides.

The corrosion protection of AISI(TM) 1010 steel by organic and inorganic zinc-rich primers

NASA Technical Reports Server (NTRS)

Danford, M. D.; Mendrek, M. J.

1995-01-01

The behavior of zinc-rich primer-coated AISI 1010 steel in 3.5-percent Na-Cl was investigated using electrochemical techniques. The alternating current (ac) method of electrochemical impedance spectroscopy (EIS), in the frequency range of 0.001 to 40,000 Hz, and the direct current (dc) method of polarization resistance (PR), were used to evaluate the characteristics of an organic, epoxy zinc-rich primer and an inorganic, ethyl silicate zinc-rich primer. A dc electromechanical galvanic corrosion test was also used to determine the corrosion current of each zinc-rich primer anode coupled to a 1010 steel cathode. Duration of the EIS/PR and galvanic testing was 21 days and 24 h, respectively. The galvanic test results demonstrated a very high current between the steel cathode and both zinc-rich primer anodes (38.8 and 135.2 microns A/sq cm for the organic and inorganic primers, respectively). The results of corrosion rate determinations demonstrated a much higher corrosion rate of the zinc in the inorganic primer than in the organic primer, due primarily to the higher porosity in the former. EIS equivalent circuit parameters confirmed this conclusion. Based on this investigation, the inorganic zinc-rich primer appears to provide superior galvanic protection and is recommended for additional study for application on solid rocket booster steel hardware.

A review on methods of recovery of acid(s) from spent pickle liquor of steel industry.

PubMed

Ghare, N Y; Wani, K S; Patil, V S

2013-04-01

Pickling is the process of removal of oxide layer and rust formed on metal surface. It also removes sand and corrosion products from the surface of metal. Acids such as sulfuric acid, hydrochloric acid are used for pickling. Hydrofluoric acid-Nitric acid mixture is used for stainless steel pickling. Pickling solutions are spent when acid concentration in pickling solutions decreases by 75-85%, which also has metal content up to 150-250 g/ dm3. Spent pickling liquor (SPL) should be dumped because the efficiency of pickling decreases with increasing content of dissolved metal in the bath. The SPL content depends on the plant of origin and the pickling method applied there. SPL from steel pickling in hot-dip galvanizing plants contains zinc(II), iron, traces of lead, chromium. and other heavy metals (max. 500 mg/dm3) and hydrochloric acid. Zinc(II) passes tothe spent solution after dissolution of this metal from zinc(II)-covered racks, chains and baskets used for transportation of galvanized elements. Unevenly covered zinc layers are usually removed in another pickling bath. Due to this, zinc(II) concentration increases even up to 110 g/dm3, while iron content may reach or exceed even 80 g/dm3 in the same solution. This review presents an overview on different aspects of generation and treatment of SPL with recourse to recovery of acid for recycling. Different processes are described in this review and higher weightage is given to membrane processes.

Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

DOEpatents

Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

1988-01-01

Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

Inertization of heavy metals present in galvanic sludge by DC thermal plasma.

PubMed

Leal Vieira Cubas, Anelise; de Medeiros Machado, Marília; de Medeiros Machado, Marina; Gross, Frederico; Magnago, Rachel Faverzani; Moecke, Elisa Helena Siegel; Gonçalvez de Souza, Ivan

2014-01-01

Galvanic sludge results from the treatment of effluents generated by the industrial metal surface treatment of industrial material, which consists in the deposition of a metal on a surface or a metal surface attack, for example, electrodeposition of conductors (metals) and non conductive, phosphate, anodizing, oxidation and/or printed circuit. The treatment proposed here is exposure of the galvanic sludge to the high temperatures provided by thermal plasma, a process which aims to vitrify the galvanic sludge and render metals (iron, zinc, and chromium) inert. Two different plasma reactors were assembled: with a DC transferred arc plasma torch and with a DC nontransferred arc plasma torch. In this way it was possible to verify which reactor was more efficient in the inertization of the metals and also to investigate whether the addition of quartzite sand to the sludge influences the vitrification of the material. Quantification of water content and density of the galvanic raw sludge were performed, as well as analyzes of total organic carbon (TOC) and identify the elements that make up the raw sludge through spectroscopy X-ray fluorescence (XRF). The chemical composition and the form of the pyrolyzed and vitrified sludge were analyzed by scanning electron microscopy with energy-dispersive X-ray spectrometer (SEM-EDS) analysis, which it is a analysis that shows the chemical of the sample surface. The inertization of the sludge was verified in leaching tests, where the leachate was analyzed by flame atomic absorption spectroscopy (FAAS). The results of water content and density were 64.35% and 2.994 g.cm(-3), respectively. The TOC analysis determined 1.73% of C in the sample of galvanic raw sludge, and XRF analysis determined the most stable elements in the sample, and showed the highest peaks (higher stability) were Fe, Zn, and Cr. The efficiency of the sludge inertization was 100% for chromium, 99% for zinc, and 100% for iron. The results also showed that the most

76 FR 22446 - Office of Hazardous Materials Safety; Notice of Applications for Modification of Special Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-21

... submitted in triplicate. If confirmation of receipt of comments is desired, include a self-addressed stamped..., Tilbury, test criteria for Hot- Ontario. Dip Galvanized cylinders from the ratio rejection in Sec. 180.209...

Influence of the cooling method on the structure of 55AlZn coatings

NASA Astrophysics Data System (ADS)

Mendala, J.

2011-05-01

In metallization processes, metals or metal alloys are used which have a low melting point and good anticorrosion properties. Moreover, they must form durable intermetallic compounds with iron or its alloys. The most common hot-dip metallization technology involves galvanizing, however, molten multi-component metal alloys are used as well. An addition of aluminium to the zinc bath causes an increase in corrosion resistance of the obtained coatings. The article presents results of tests of obtaining coatings by the batch hot-dip method in an 55AlZn bath. Kinetics of the coating growth in the tested alloys were determined in the changeable conditions of bath temperature, dip time and type of cooling. The structure of coatings and their phase composition were revealed. As a result of the tests performed, it has been found that an increase in total thickness of the coatings as a function of the dipping time at a constant temperature is almost of a parabolic nature, whereas an increase in the transient layer is of a linear nature. The structure was identified by the XRD analysis and the morphology of the coatings was tested by means of SEM. It has been found that the cooling process with the use of higher rates of cooling causes a size reduction of the structure in the outer layer and a reduction of thickness of both the intermediate diffusion layer and the whole coating by ca. 25 %.

46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

Code of Federal Regulations, 2013 CFR

2013-10-01

... materials and pressure design of subchapter F of this chapter. (b) Piping for salt-water service must be of a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of extra-heavy...

46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

Code of Federal Regulations, 2014 CFR

2014-10-01

... materials and pressure design of subchapter F of this chapter. (b) Piping for salt-water service must be of a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of extra-heavy...

46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

Code of Federal Regulations, 2010 CFR

2010-10-01

... materials and pressure design of subchapter F of this chapter. (b) Piping for salt-water service must be of a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of extra-heavy...

46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

Code of Federal Regulations, 2011 CFR

2011-10-01

... materials and pressure design of subchapter F of this chapter. (b) Piping for salt-water service must be of a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of extra-heavy...

46 CFR 128.220 - Class II non-vital systems-materials and pressure design.

Code of Federal Regulations, 2012 CFR

2012-10-01

... materials and pressure design of subchapter F of this chapter. (b) Piping for salt-water service must be of a corrosion-resistant material and, if ferrous, be hot-dip galvanized or be at least of extra-heavy...

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

NASA Astrophysics Data System (ADS)

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.

Characteristics of joining and hybrid composite forging of aluminum solid parts and galvanized steel sheets

NASA Astrophysics Data System (ADS)

Wesling, V.; Treutler, K.; Bick, T.; Stonis, M.; Langner, J.; Kriwall, M.

2018-06-01

In lightweight construction, light metals like aluminum are used in addition to high-strength steels. However, a welded joint of aluminum and steel leads to the precipitation of brittle, intermetallic phases and contact corrosion. Nevertheless, to use the advantages of this combination in terms of weight saving composite hybrid forging has been developed. In this process, an aluminum solid part and a steel sheet were formed in a single step and joined at the same time with zinc as brazing material. For this purpose, the zinc was applied by hot dipping on the aluminum in order to produce a connection via this layer in a forming process, under pressure and heat. Due to the formed intermediate layer of zinc, the formation of the Fe-Al intermetallic phases and the contact corrosion are excluded. By determining the mathematical relationships between joining parameters and the connection properties the strength of a specific joint geometry could be adjusted to reach the level of conventional joining techniques. In addition to the presentation of the joint properties, the influence of the joining process on the structure of the involved materials is also shown. Furthermore, the failure behavior under static tensile and shear stress will be shown.

Influence of thermal treatment temperature on high-performance varistors prepared by hot-dipping tin oxide thin films in Nb2O5 powder

NASA Astrophysics Data System (ADS)

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

2018-06-01

SnOx-Nb2O5 thin film varistors were prepared by hot-dipping oxygen-deficient tin oxide films in Nb2O5 powder in air, and the influence of hot-dipping temperature (HDT) on the varistor performance of the samples was systematically explored. When the HDT increased from 300 to 700 °C, the nonlinear coefficient of the samples raised first and then dropped down, reaching the maximum of 14.73 at 500 °C, and the breakdown electric field exhibited a similar variation trend, gaining the peak value of 0.0201 V/nm at this temperature. Correspondingly, the leakage current decreased first and then increased with increasing HDT, reaching the minimum of 17.1 mA/cm2 at 500 °C. Besides, it was proposed that a grain-boundary defect barrier model was responsible for the nonlinear behavior of the obtained SnOx-Nb2O5 film varistors. This high-performance thin film varistor with nanoscaled thickness might be much promising in nano-devices or devices working in low voltage.

The effect of environmentally friendly hot-dipping auxiliary on the morphology of alloy coatings

NASA Astrophysics Data System (ADS)

Chen, Suhong; Guo, Kai; Zhu, Yi; Gao, Feng; Han, Zhijun

2017-10-01

Zn-Al-Mg-RE hot-dip alloy coatings which prepared by the environmentally friendly plating auxiliary were investigated by X-ray diffraction (XRD), SEM analysis and salt spray measurement. Significant variation in coating surface morphology and element content are observed with increasing content of Al and Mg in this paper. A reinforced ternary eutectic Zn-Al-MgZn2 is confirmed which attribute to improvement metallographic structure derived from certain ternary eutectic reaction in alloy solidification. For Mg-containing coatings, the enhanced corrosion resistance is observed by corrosion resistance test in salt spray at 35°C with 5% NaCl in terms of corrosion weight changes. It is found that the incorporation of 3 wt.% Mg and 0.1 wt.% rare earth element in to Zn-Al-Mg-RE bath caused structural refinement of the crystal and also helped to achieve excellent surface morphology.

Formation of microstructural features in hot-dip aluminized AISI 321 stainless steel

NASA Astrophysics Data System (ADS)

Huilgol, Prashant; Rajendra Udupa, K.; Udaya Bhat, K.

2018-02-01

Hot-dip aluminizing (HDA) is a proven surface coating technique for improving the oxidation and corrosion resistance of ferrous substrates. Although extensive studies on the HDA of plain carbon steels have been reported, studies on the HDA of stainless steels are limited. Because of the technological importance of stainless steels in high-temperature applications, studies of their microstructural development during HDA are needed. In the present investigation, the HDA of AISI 321 stainless steel was carried out in a pure Al bath. The microstructural features of the coating were studied using scanning electron microscopy and transmission electron microscopy. These studies revealed that the coating consists of two regions: an Al top coat and an aluminide layer at the interface between the steel and Al. The Al top coat was found to consist of intermetallic phases such as Al7Cr and Al3Fe dispersed in an Al matrix. Twinning was observed in both the Al7Cr and the Al3Fe phases. Furthermore, the aluminide layer comprised a mixture of nanocrystalline Fe2Al5, Al7Cr, and Al. Details of the microstructural features are presented, and their formation mechanisms are discussed.

Study on the wiping gas jet in continuous galvanizing line

NASA Astrophysics Data System (ADS)

Kweon, Yong-Hun; Kim, Heuy-Dong

2011-09-01

In the continuous hot-dip galvanizing process, the gas-jet wiping is used to control the coating thickness of moving steel strip. The high speed gas-jet discharged from the nozzle slot impinges on the strip, and at this moment, wipes the liquid coating layer dragged by a moving strip. The coating thickness is generally influenced on the flow characteristics of wiping gas-jet such as the impinging pressure distribution, pressure gradient and shear stress distribution on the surface of strip. The flow characteristics of wiping gas-jet mentioned above depends upon considerably both the process operating conditions such as the nozzle pressure, nozzle-to-strip distance and line speed, and the geometry of gas-jet wiping apparatus such as the height of nozzle slot. In the present study, the effect of the geometry of nozzle on the coating thickness is investigated with the help of a computational fluid dynamics method. The height of nozzle slot is varied in the range of 0.6mm to 1.7mm. A finite volume method (FVM) is employed to solve two-dimensional, steady, compressible Navier-Stokes equations. Based upon the results obtained, the effect of the height of nozzle slot in the gas-jet wiping process is discussed in detail. The computational results show that for a given standoff distance between the nozzle to the strip, the effective height of nozzle slot exists in achieving thinner coating thickness.

Effect of the Type of Surface Treatment and Cement on the Chloride Induced Corrosion of Galvanized Reinforcements

NASA Astrophysics Data System (ADS)

Tittarelli, Francesca; Mobili, Alessandra; Vicerè, Anna Maria; Roventi, Gabriella; Bellezze, Tiziano

2017-10-01

The effect of a new passivation treatment, obtained by immersion of the galvanized reinforcements in a trivalent chromium salts based solution, on the chlorides induced corrosion has been investigated. To investigate also the effect of cement alkalinity on corrosion behaviour of reinforcements, concretes manufactured with three different European cements were compared. The obtained results show that the alternative treatment based on hexavalent chromium-free baths forms effective protection layers on the galvanized rebar surfaces. The higher corrosion rates of zinc coating in concrete manufactured with Portland cement compared to those recorded for bars in concrete manufactured with pozzolanic cement depends strongly on the higher chloride content at the steel concrete interface.

Galvanic Liquid Applied Coating System for Protection of Embedded Steel Surfaces from Corrosion

NASA Technical Reports Server (NTRS)

Curran, Joseph; MacDowell, Louis; Voska, N. (Technical Monitor)

2002-01-01

The corrosion of reinforcing steel in concrete is an insidious problem for the Kennedy Space Center, government agencies, and the general public. Existing corrosion protection systems on the market are costly, complex, and time-consuming to install, require continuous maintenance and monitoring, and require specialized skills for installation. NASA's galvanic liquid-applied coating offers companies the ability to conveniently protect embedded steel rebar surfaces from corrosion. Liquid-applied inorganic galvanic coating contains one ore more of the following metallic particles: magnesium, zinc, or indium and may contain moisture attracting compounds that facilitate the protection process. The coating is applied to the outer surface of reinforced concrete so that electrical current is established between metallic particles and surfaces of embedded steel rebar; and electric (ionic) current is responsible for providing the necessary cathodic protection for embedded rebar surfaces.

Galvanizing action: conclusions and next steps for mainstreaming zinc interventions in public health programs.

PubMed

Brown, Kenneth H; Baker, Shawn K

2009-03-01

This paper summarizes the results of the foregoing reviews of the impact of different intervention strategies designed to enhance zinc nutrition, including supplementation, fortification, and dietary diversification or modification. Current evidence indicates a beneficial impact of such interventions on zinc status and zinc-related functional outcomes. Preventive zinc supplementation reduces the incidence of diarrhea and acute lower respiratory tract infection among young children, decreases mortality of children over 12 months of age, and increases growth velocity. Therapeutic zinc supplementation during episodes of diarrhea reduces the duration and severity of illness. Zinc fortification increases zinc intake and total absorbed zinc, and recent studies are beginning to confirm a positive impact of zinc fortification on indicators of population zinc status. To assist with the development of zinc intervention programs, more information is needed on the prevalence of zinc deficiency in different countries, and rigorous evaluations of the effectiveness of large-scale zinc intervention programs should be planned. Recommended steps for scaling up zinc intervention programs, with or without other micronutrients, are described. In summary, there is now clear evidence of the benefit of selected interventions to reduce the risk of zinc deficiency, and a global commitment is urgently needed to conduct systematic assessments of population zinc status and to develop interventions to control zinc deficiency in the context of existing public health and nutrition programs.

Zinc toxicology following particulate inhalation

PubMed Central

Cooper, Ross G.

2008-01-01

The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl2 inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection. PMID:20040991

Nanoporous metallic surface: Facile fabrication and enhancement of boiling heat transfer

NASA Astrophysics Data System (ADS)

Tang, Yong; Tang, Biao; Qing, Jianbo; Li, Qing; Lu, Longsheng

2012-09-01

The paper reports a flexible and low-cost approach, hot-dip galvanizing and dealloying, for the fabrication of enhanced nanoporous metallic surfaces. A Cu-Zn alloy layer mainly composed of γ-Cu5Zn8 and β'-CuZn was formed during the hot-dipping process. The multiple oxidation peaks recorded in the anodic liner sweep voltammetry measurements indicate different dezincification preferences of the alloy phases. A nanoporous copper surface with approximately 50-200 nm in pore size was obtained after a free corrosion process. The nanoporous structure improves the surface wettability and shows dramatic reduction of wall superheat compared to that of the plain surface in the pool-boiling experiments.

Adsorption of Cashew Allergens to Acid-Etched Zinc Metal Particles

USDA-ARS?s Scientific Manuscript database

Galvanized metal surfaces are approved by the FDA for use in many food processing steps. Food allergens can cause severe reactions even in very small amounts, and surfaces contaminated with allergens could pose a serious threat. The binding of cashew allergens to zinc particles was evaluated. Whi...

Cross Coating Weight Control by Electromagnetic Strip Stabilization at the Continuous Galvanizing Line of ArcelorMittal Florange

NASA Astrophysics Data System (ADS)

Guelton, Nicolas; Lopès, Catherine; Sordini, Henri

2016-08-01

In hot dip galvanizing lines, strip bending around the sink roll generates a flatness defect called crossbow. This defect affects the cross coating weight distribution by changing the knife-to-strip distance along the strip width and requires a significant increase in coating target to prevent any risk of undercoating. The already-existing coating weight control system succeeds in eliminating both average and skew coating errors but cannot do anything against crossbow coating errors. It has therefore been upgraded with a flatness correction function which takes advantage of the possibility of controlling the electromagnetic stabilizer. The basic principle is to split, for every gage scan, the coating weight cross profile of the top and bottom sides into two, respectively, linear and non-linear components. The linear component is used to correct the skew error by realigning the knives with the strip, while the non-linear component is used to distort the strip in the stabilizer in such a way that the strip is kept flat between the knives. Industrial evaluation is currently in progress but the first results have already shown that the strip can be significantly flattened between the knives and the production tolerances subsequently tightened without compromising quality.

Galvanic coupling between D6AC steel, 6061-T6 aluminum, Inconel 718 and graphite-epoxy composite material: Corrosion occurrence and prevention

NASA Technical Reports Server (NTRS)

Danford, M. D.; Higgins, R. H.

1983-01-01

The effects of galvanic coupling between D6AC steel, 6061-T6 aluminum, Inconel 718, and graphite-epoxy composite material (G/E) in 3.5% NaCl were studied. Measurements of corrosion potentials, galvanic currents and corrosion rates of the bare metals using weight-loss methods served to establish the need for corrosion protection in cases where D6AC steel and 6061-T6 aluminum are galvanically coupled to G/E in salt water while Inconel 718 was shown to be compatible with G/E. Six tests were made to study corrosion protective methods for eliminating galvanic corrosion in the cases of D6AC steel and 6061-T6 aluminum coupled to G/E. These results indicate that, when the G/E is completely coated with paint or a paint/polyurethane resin combination, satisfactory protection of the D6AC steel is achieved with either a coat of zinc-rich primer or a primer/topcoat combination. Likewise, satisfactory corrosion protection of the aluminum is achieved by coating it with an epoxy coating system.

The Role of Zinc Layer During Wetting of Aluminium on Zinc-coated Steel in Laser Brazing and Welding

NASA Astrophysics Data System (ADS)

Gatzen, M.; Radel, T.; Thomy, C.; Vollertsen, F.

The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading of liquid aluminium on the coated surface. For industrial brazing and welding processes these zinc-coatings enable a fluxless joining between aluminium and steel in many cases. Yet, the reason for the beneficial effect of the zinc to the wetting process is not completely understood. Fundamental investigations on the wetting behaviour of single aluminium droplets on different zinc-coated steel surfaces have revealed a distinct difference between coated surfaces at room temperature and at elevated temperature regarding the influence of different coating thicknesses. In this paper the case of continuous laser brazing and welding processes of aluminium and commercial galvanized zinc-coated steel sheets are presented. It is shown that in the case of bead-on-plate laser beam brazing, the coating thickness has a measureable effect on the resulting wetting angle and length but does not have a significant impact in case of overlap laser beam welding. This might be linked to different heat transfer conditions. The results also strongly indicate that proper initialbreakup of oxide layers is still required to accomplish good wetting on zinc-coated surfaces.

Exposure testing of fasteners in preservative treated wood : gravimetric corrosion rates and corrosion product analyses

Treesearch

Samuel L. Zelinka; Rebecca J. Sichel; Donald S. Stone

2010-01-01

Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27oC at 100% relative humidity for 1 year. The...

Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

NASA Astrophysics Data System (ADS)

Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

2017-10-01

In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

SILICATES FOR CORROSION CONTROL IN BUILDING POTABLE WATER SYSTEMS

EPA Science Inventory

Silicates have been used to control the corrosion of drinking water distribution system materials. Previous work has shown that they are particularly useful in reducing the release of zinc from galvanized materials in hot water systems. Negatively charged silicate species were re...

Growth of ZnO nanorods on glass substrate deposited using dip coating method

NASA Astrophysics Data System (ADS)

Rani, Rozina Abdul; Ghafar, Safiah Ab; Zoolfakar, Ahmad Sabirin; Rusop, M.

2018-05-01

ZnO unique properties make it attractive for electronics and optoelectronics application. There are varieties synthesis of ZnO nanostructure but one of the best ways is by using dip coating method due to its simplicity, low cost and reliability. This research investigated the effect of precursor concentration on the morphology of ZnO nanorods using dip coating technique. ZnO nanorods is synthesized by using zinc nitrate as precursor and glass slide as substrate. The morphology of ZnO is characterized using Field Emission Scanning Electron Microscope (FESEM). By using different concentration of precursor, each outcome demonstrated diverse morphologies.

Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

NASA Astrophysics Data System (ADS)

Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

2018-03-01

Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

UV spectroscopy of Z Chamaeleontis. I - Time dependent dips in superoutburst

NASA Technical Reports Server (NTRS)

Harlaftis, E. T.; Hassall, B. J. M.; Naylor, T.; Charles, P. A.; Sonneborn, G.

1992-01-01

Extensive IUE observations of the dwarf nova Z Cha during the 1987 April superoutburst and IUE-Exosat observations during the 1985 July superoutburst are presented. The UV light curve shows two dips when folded on the orbital period. One dip, at orbital phase 0.8 becomes shallower as the superoutburst progresses and can be associated with decreasing mass transfer rate from the secondary star. The other dip, at orbital phase 0.15, appears after the development of the superhump and some days after the occurrence of the largest dip at phase 0.8. The continuum flux distribution during superoutbursts is fainter and redder than in low-inclination dwarf novae during superoutbursts. This is interpreted in terms of the extended vertical disk structure which occults the hot inner parts of the disk with the development of a 'cool' bulge on the edge of the disk at orbital phase 0.75. Details of the behaviour of the UV emission lines during eclipse and away from eclipse are discussed.

Synthesis and Crystal Structure of Dibromido{2-[(4-tert-butylmethylphenyl) iminomethyl]pyridine-κ2 N, N'}Zinc

NASA Astrophysics Data System (ADS)

Khalaj, M.; Ghazanfarpour-Darjani, M.; Seftejani, F. B.; Lalegani, A.

2017-12-01

The title compound [Zn( dip)Br2] was synthesized using the Schiff base bidentate ligand (E)-4- tert-butyl- N-(pyridine-2-ylmethylene)benzeneamine ( dip) and zinc(II) bromide salts. It has been characterized by elemental analysis, X-ray diffraction, and optical spectroscopy. The X-ray diffraction analysis demonstrates that in this structure, the zinc(II) ion is located on an inversion center and exhibits a ZnN2Br2 tetrahedral geometry. In this structure the dip ligand is coordinated with zinc(II) ion in a cyclic-bidentate fashion forming a five-membered metallocyclic ring. The compound crystallizes in the monoclinic sp. gr. P21/ m with a = 9.2700(13) Å, b = 7.6128(11) Å, c = 12.3880(17) Å, and β = 97.021(3)°.

Bioavailability of zinc in two zinc sulfate by-products of the galvanizing industry.

PubMed

Edwards, H M; Boling, S D; Emmert, J L; Baker, D H

1998-10-01

Two Zn depletion/repletion assays were conducted with chicks to determine the relative bioavailability (RBV) of Zn from two new by-products of the galvanizing industry. Using a soy concentrate-dextrose diet, slope-ratio methodology was employed to evaluate two different products: Fe-ZnSO4 x H2O with 20.2% Fe and 13.0% Zn, and Zn-FeSO4 x H2O with 14.2% Fe and 20.2% Zn. Feed-grade ZnSO4 x H2O was used as a standard. Weight gain, tibia Zn concentration, and total tibia Zn responded linearly (P < 0.01) to Zn supplementation from all three sources. Slope-ratio calculations based on weight gain established average Zn RBV values of 98% for Fe-ZnSO4 x H2O and 102% for Zn-FeSO4 x H2O, and these values were not different (P > 0.10) from the ZnSO4 standard (100%). Slope-ratio calculations based on total tibia Zn established average Zn RBV values of 126% for Fe-ZnSO4 x H2O and 127% for Zn-FeSO4 x H2O, and these values were greater (P < 0.01) than those of the ZnSO4 standard (100%). It is apparent that both mixed sulfate products of Fe and Zn are excellent sources of bioavailable Zn.

3D Model of the Neal Hot Springs Geothermal Area

DOE Data Explorer

Faulds, James E.

2013-12-31

The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.

Exposure test of fasteners in preservative-treated wood

Treesearch

Samuel L. Zelinka; Douglas R. Rammer

2006-01-01

This study examined nails and screws exposed to ACQ-treated wood for up to 12 months in a controlled environment. The environment (27ºC, 100% relative humidity) was chosen so that comparisons could be made with previous exposure tests run using CCA-treated wood in the same environment. Five types of fasteners (common 8d nail, hot-dipped galvanized 8d nail, 4d aluminum...

Use of Repeated Fluoropolymer Suspensions to Obtain Composite Electrochemical Coating Based on Zinc

NASA Astrophysics Data System (ADS)

Musikhina, T. A.; Zemtsova, E. A.; Fuks, C. L.

2017-11-01

This article deals with the issues of utilization of the waste products of fluoropolymers, namely, the suspensions of fluoroplasts that have lost their consumer properties. Such waste is recommended to be used as a filler of zinc coatings to provide increased corrosion resistance. Using the method of mathematical planning of the experiment, the authors establish the optimal compositions of galvanizing chloride-ammonium electrolytes to obtain the corrosion-resistant composite electrochemical coatings (CEC) of zinc-fluoropolymer. As a result, coatings with a finely crystalline structure were obtained differing in the distribution pattern on the surface of the samples and depending on the variation in the zinc concentration in the electrolytes. The samples of steel reinforcement with the zinc-fluoropolymer coating were tested on corrosion resistance. The increase of anticorrosive properties in CEC zinc-fluoropolymer and a slight decrease in microhardness were indicated.

21 CFR 882.1540 - Galvanic skin response measurement device.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Galvanic skin response measurement device. 882... Galvanic skin response measurement device. (a) Identification. A galvanic skin response measurement device... electrical resistance of the skin and the tissue path between two electrodes applied to the skin. (b...

21 CFR 882.1540 - Galvanic skin response measurement device.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Galvanic skin response measurement device. 882... Galvanic skin response measurement device. (a) Identification. A galvanic skin response measurement device... electrical resistance of the skin and the tissue path between two electrodes applied to the skin. (b...

21 CFR 882.1540 - Galvanic skin response measurement device.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Galvanic skin response measurement device. 882... Galvanic skin response measurement device. (a) Identification. A galvanic skin response measurement device... electrical resistance of the skin and the tissue path between two electrodes applied to the skin. (b...

21 CFR 882.1540 - Galvanic skin response measurement device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Galvanic skin response measurement device. 882... Galvanic skin response measurement device. (a) Identification. A galvanic skin response measurement device... electrical resistance of the skin and the tissue path between two electrodes applied to the skin. (b...

Simulation on the steel galvanic corrosion and acoustic emission

NASA Astrophysics Data System (ADS)

Yu, Yang; Shi, Xin; Yang, Ping

2015-12-01

Galvanic corrosion is a very destructive localized corrosion. The research on galvanic corrosion could determine equipment corrosion and prevent the accidents occurrence. Steel corrosion had been studied by COMSOL software with mathematical modeling. The galvanic corrosion of steel-aluminum submerged into 10% sodium chloride solution had been on-line detected by PIC-2 acoustic emission system. The results show that the acoustic emission event counts detected within unit time can qualitative judge galvanic corrosion rate and further erosion trend can be judged by the value changes.

Effects of surface hydroxylation on adhesion at zinc/silica interfaces.

PubMed

Le, Ha-Linh Thi; Goniakowski, Jacek; Noguera, Claudine; Koltsov, Alexey; Mataigne, Jean-Michel

2018-06-06

The weak interaction between zinc and silica is responsible for the poor performance of anti-corrosive galvanic zinc coatings on modern advanced high-strength steels, which are fundamental in the automotive industry, and important for rail transport, shipbuilding, and aerospace. With the goal of identifying possible methods for its improvement, we report an ab initio study of the effect of surface hydroxylation on the adhesion characteristics of model zinc/β-cristobalite interfaces, representative of various surface hydroxylation/hydrogenation conditions. We show that surface silanols resulting from dissociative water adsorption at the most stable stoichiometric (001) and (111) surfaces prevent strong zinc-silica interactions. However, dehydrogenation of such interfaces produces oxygen-rich zinc/silica contacts with excellent adhesion characteristics. These are due to partial zinc oxidation and the formation of strong iono-covalent Zn-O bonds between zinc atoms and the under-coordinated excess anions, remnant of the hydroxylation layer. Interestingly, these interfaces appear as the most thermodynamically stable in a wide range of realistic oxygen-rich and hydrogen-lean environments. We also point out that the partial oxidation of zinc atoms in direct contact with the oxide substrate may somewhat weaken the cohesion in the zinc deposit itself. This fundamental analysis of the microscopic mechanisms responsible for the improved zinc wetting on pre-hydroxylated silica substrates provides useful guidelines towards practical attempts to improve adhesion.

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

NASA Astrophysics Data System (ADS)

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.

Effect of sulfur and magnesium on hot ductility and pitting corrosion for Inconel 690 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, K.; Zhang, B.; Zhang, S.

1995-12-31

A series of hot tensile tests has been performed to study the effect of sulfur and magnesium on hot ductility of Inconel 690 alloy. The hot ductility has been evaluated from the reduction of area in hot tensile tests using a Gleeble testing machine. The value of reduction in area decreased with increasing sulfur content in the temperature range from 900 C to 1,200 C. When sulfur content was larger than 0.0025%, a ductility dip appeared, and the greater the sulfur content, the deeper and wider the ductility dip. The Scanning Electron Microscope (SEM) analyses showed that the fracture appearancesmore » changed gradually from transgranular to intergranular with increasing sulfur content, meanwhile sulfur and titanium segregation were observed at grain boundaries. The ductility dip of 690 alloy with relatively higher sulfur content could be inhibited by adding appropriate amount of magnesium. However, excessive addition led to magnesium precipitation, which was detrimental to hot ductility. The pitting test has also been conducted and the results showed that pitting rate obviously increased with increasing sulfur content.« less

Galvanic cell for processing of used nuclear fuel

DOEpatents

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.

77 FR 28404 - Galvanized Steel Wire From China and Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

...)] Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1\\ developed in the... reason of imports from China of galvanized steel wire, provided for in subheadings 7217.20.30, 7217.20.45... reason of imports from Mexico of galvanized steel wire, provided for in subheadings 7217.20.30, 7217.20...

Ion exchange treatment of rinse water generated in the galvanizing process.

PubMed

Marañón, Elena; Fernández, Yolanda; Castrillón, Leonor

2005-01-01

A study was conducted of the viability of using the cationic exchange resins Amberlite IR-120 and Lewatit SP-112 to treat rinse water generated in the galvanizing process as well as acidic wastewater containing zinc (Zn) and iron (Fe). Solutions containing either 100 mg/L of Zn at pH 5.6 (rinse water) or Fe and Zn at concentrations of 320 and 200 mg/L at pH 1.5 (acidic water), respectively, were percolated through packed beds until the resins were exhausted. Breakthrough capacities obtained ranged between 1.1 and 1.5 meq metal/mL resin. The elution of metal and the regeneration of resins were performed with hydrochloric acid. The influence of the flowrate used during the loading stage was also studied, with 0.5 bed volumes/min (3.2 cm/min) found to be the optimum flowrate.

Properties of Galvanized and Galvannealed Advanced High Strength Hot Rolled Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

V.Y. Guertsman; E. Essadiqi; S. Dionne

2008-04-01

The objectives of the project were (i) to develop the coating process information to achieve good quality coatings on 3 advanced high strength hot rolled steels while retaining target mechanical properties, (ii) to obtain precise knowledge of the behavior of these steels in the various forming operations and (iii) to establish accurate user property data in the coated conditions. Three steel substrates (HSLA, DP, TRIP) with compositions providing yield strengths in the range of 400-620 MPa were selected. Only HSLA steel was found to be suitable for galnaizing and galvannealing in the hot rolled condition.

A Statistical Review of Alternative Zinc and Copper Extraction from Mineral Fertilizers and Industrial By-Products.

PubMed

Cenciani de Souza, Camila Prado; Aparecida de Abreu, Cleide; Coscione, Aline Renée; Alberto de Andrade, Cristiano; Teixeira, Luiz Antonio Junqueira; Consolini, Flavia

2018-01-01

Rapid, accurate, and low-cost alternative analytical methods for micronutrient quantification in fertilizers are fundamental in QC. The purpose of this study was to evaluate whether zinc (Zn) and copper (Cu) content in mineral fertilizers and industrial by-products determined by the alternative methods USEPA 3051a, 10% HCl, and 10% H2SO4 are statistically equivalent to the standard method, consisting of hot-plate digestion using concentrated HCl. The commercially marketed Zn and Cu sources in Brazil consisted of oxides, carbonate, and sulfate fertilizers and by-products consisting of galvanizing ash, galvanizing sludge, brass ash, and brass or scrap slag. The contents of sources ranged from 15 to 82% and 10 to 45%, respectively, for Zn and Cu. The Zn and Cu contents refer to the variation of the elements found in the different sources evaluated with the concentrated HCl method as shown in Table 1. A protocol based on the following criteria was used for the statistical analysis assessment of the methods: F-test modified by Graybill, t-test for the mean error, and linear correlation coefficient analysis. In terms of equivalents, 10% HCl extraction was equivalent to the standard method for Zn, and the results of the USEPA 3051a and 10% HCl methods indicated that these methods were equivalents for Cu. Therefore, these methods can be considered viable alternatives to the standard method of determination for Cu and Zn in mineral fertilizers and industrial by-products in future research for their complete validation.

Physicochemistry, morphology and leachability of selected metals from post-galvanized sewage sludge from screw factory in Łańcut, SE Poland

NASA Astrophysics Data System (ADS)

Galas, Dagmara; Kalembkiewicz, Jan; Sitarz-Palczak, Elżbieta

2016-12-01

Morphology, physicochemical properties, chemical composition of post-galvanized sewage sludge from Screw Factory in Łańcut, leachability and mobility of metals has been analyzed. The analyses with the use of scanning electron microscope with an adapter to perform chemical analysis of microsites (EDS) showed that the material is characterized by a high fragmentation and a predominant number of irregularly shaped grains. The sewage sludge is alkaline with a large loss of ignition (34.6%) and small bulk density (< 1 g/cm3). The EDS analyses evidenced presence of oxygen, silicon, calcium, chromium, iron and zinc in all examined areas, and presence of manganese and copper in selected areas indicating a non-uniform distribution of metals in the sewage sludge. Within one-stage mineralization and FAAS technique a predominant share of calcium, zinc and iron in terms of dry matter was recorded in the sewage sludge. The contents of Co, Cr, Cu, K, Mn, Ni and Pb in sewage sludge are below 1%. Evaluation of mobility and leaching of metals in sewage sludge was carried out by means of two parameters: accumulation coefficient of mobile fractions and leaching level related to the mass solubility of sewage sludge. The results indicate that the short-term or long-term storage of not inactivated post-galvanized sewage sludge can result in release of metals.

Scalable, "Dip-and-Dry" Fabrication of a Wide-Angle Plasmonic Selective Absorber for High-Efficiency Solar-Thermal Energy Conversion.

PubMed

Mandal, Jyotirmoy; Wang, Derek; Overvig, Adam C; Shi, Norman N; Paley, Daniel; Zangiabadi, Amirali; Cheng, Qian; Barmak, Katayun; Yu, Nanfang; Yang, Yuan

2017-11-01

A galvanic-displacement-reaction-based, room-temperature "dip-and-dry" technique is demonstrated for fabricating selectively solar-absorbing plasmonic-nanoparticle-coated foils (PNFs). The technique, which allows for facile tuning of the PNFs' spectral reflectance to suit different radiative and thermal environments, yields PNFs which exhibit excellent, wide-angle solar absorptance (0.96 at 15°, to 0.97 at 35°, to 0.79 at 80°), and low hemispherical thermal emittance (0.10) without the aid of antireflection coatings. The thermal emittance is on par with those of notable selective solar absorbers (SSAs) in the literature, while the wide-angle solar absorptance surpasses those of previously reported SSAs with comparable optical selectivities. In addition, the PNFs show promising mechanical and thermal stabilities at temperatures of up to 200 °C. Along with the performance of the PNFs, the simplicity, inexpensiveness, and environmental friendliness of the "dip-and-dry" technique makes it an appealing alternative to current methods for fabricating selective solar absorbers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of Thermal Spray Coating Applications in the Steel Industry: Part 2—Zinc Pot Hardware in the Continuous Galvanizing Line

NASA Astrophysics Data System (ADS)

Matthews, S.; James, B.

2010-12-01

This two-part article series reviews the application of thermal spray coating technology in the production of steel and steel sheet products. Part 2 of this article series is dedicated to coating solutions in the continuous galvanizing line. The corrosion mechanisms of Fe- and Co-based bulk materials are briefly reviewed as a basis for the development of thermal spray coating solutions. WC-Co thermal spray coatings are commonly applied to low Al-content galvanizing hardware due to their superior corrosion resistance compared to Fe and Co alloys. The effect of phase degradation, carbon content, and WC grain size are discussed. At high Al concentrations, the properties of WC-Co coatings degrade significantly, leading to the application of oxide-based coatings and corrosion-resistant boride containing coatings. The latest results of testing are summarized, highlighting the critical coating parameters.

40 CFR 465.20 - Applicability; description of the galvanized basis material subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... galvanized basis material subcategory. 465.20 Section 465.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS COIL COATING POINT SOURCE CATEGORY Galvanized Basis Material Subcategory § 465.20 Applicability; description of the galvanized basis material...

Evaluation of inorganic zinc-rich primers using Electrochemical Impedance Spectroscopy (EIS) in combination with atmospheric exposure

NASA Technical Reports Server (NTRS)

Calle, Luz M.

1994-01-01

This investigation explored the use of Electrochemical Impedance Spectroscopy (EIS) in combination with atmospheric exposure as a short term method for analyzing the performance of twenty-one commercially available zinc-rich primers. The twenty-one zinc-rich primers were: Carboline CZ-11, Ameron Devoe-Marine Catha-Coat 304, Briner V-65, Ameron D-21-9, Sherwin Williams Zinc Clad II, Carboline CZ-D7, Ameron D-4, Dupont Ganicin 347WB, Porter TQ-4374H, Inorganic Coatings IC-531, Subox Galvanox IV, Southern Coatings Chemtec 600, GLidden Glidzinc 5530, Byco SP-101, Tnemec 90E-75, Devoe Catha-Coat 302H, Glidden Glidzinc 5536, Koppers 701, Ameron D-21-5, Coronado 935-152, and Subox Galvanox V. Data were also collected on galvanized steel for comparison purposes. A library of Bode magnitude plots was generated for each coating including curves for the initial time and after each week of atmospheric exposure at the Beach Corrosion Test site near the Space Shuttle launch pad at the Kennedy Space Center for up to four weeks. Subsequent measurements were collected after 8 weeks and after one year of atmospheric exposure. Analysis of the impedance data was performed with the purpose of identifying parameters that could be used to predict the long-term performance of zinc-rich primers. It has been shown that there is a correlation between the long-term performance of zinc-rich primers and several parameters obtained from EIS measurements in combination with atmospheric exposure. The equivalent circuit R2(R2C(R3W)) provided a satisfactory fit for the EIS data. The corrosion potential and the R2 resistance are parameters indicative of the galvanic mechanism of protection. The capacitance of the coating is related to the barrier mechanism of protection.

Zinc Extraction from Zinc Plants Residue Using Selective Alkaline Leaching and Electrowinning

NASA Astrophysics Data System (ADS)

Ashtari, Pedram; Pourghahramani, Parviz

2015-10-01

Annually, a great amount of zinc plants residue is produced in Iran. One of them is hot filter cake (known as HFC) which can be used as a secondary resource of zinc, cobalt and manganese. Unfortunately, despite its heavy metal content, the HFC is not treated. For the first time, zinc was selectively leached from HFC employing alkaline leaching. Secondly, leaching was optimized to achieve maximum recovery using this method. Effects of factors like NaOH concentration (C = 3, 5, 7 and 9 M), temperature (T = 50, 70, 90 and 105 °C), solid/liquid ratio (weight/volume, S/L = 1/10 and 1/5 W/V) and stirring speed (R = 500 and 800 rpm) were studied on HFC leaching. L16 orthogonal array (OA, two factors in four levels and two factors in two levels) was applied to determine the optimum condition and the most significant factor affecting the overall zinc extraction. As a result, maximum zinc extraction was 83.4 %. Afterwards, a rough test was conducted for zinc electrowinning from alkaline solution according to the common condition available in literature by which pure zinc powder (99.96 %) was successfully obtained.

Optimizing the withdrawal speed using dip coating for optical sensor

NASA Astrophysics Data System (ADS)

Samat, S. F. A.; Sarah, M. S. P.; Idros, M. Faizol Md; Rusop, M.

2018-05-01

The processing route of sol-gel has been used for many productions of thin film using metal oxide such as titanium dioxide, zinc oxide, carbon dioxide and so on. For this research the thin film phase was studied has high transmittance using dip coating technique with different withdrawal speed for optical sensing. The result obtained from optical transmittance spectra that transmits at 30nm and bend at 350nm to 800nm was in the visible light wavelength range. From the data, the withdrawal speed was low at 5s and 10s could give the highest transmittance which were 90.41% and 87.91% respectively.

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

PubMed Central

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, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. 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 O2. 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 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. PMID:22291514

Galvanic Manufacturing in the Cities of Russia: Potential Source of Ambient Nanoparticles

PubMed Central

Golokhvast, Kirill S.; Shvedova, Anna A.

2014-01-01

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. PMID:25329582

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

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false RUS specification for seven wire galvanized steel..., ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.370 RUS specification for seven wire galvanized... Steel Wire Strand, issued May 1978. All seven wire galvanized steel strand purchased after April 1, 1990...

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

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false RUS specification for seven wire galvanized steel..., ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.370 RUS specification for seven wire galvanized... Steel Wire Strand, issued May 1978. All seven wire galvanized steel strand purchased after April 1, 1990...

75 FR 17162 - Dipping and Coating Operations (Dip Tanks) Standard; Extension of the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-05

...] Dipping and Coating Operations (Dip Tanks) Standard; Extension of the Office of Management and Budget's... Standard on Dipping and Coating Operations (Dip Tanks) (29 CFR 1910.126(g)(4)). DATES: Comments must be... of efforts in obtaining information (29 U.S.C. 657). The Standard on Dipping and Coating Operations...

78 FR 21159 - Additional Requirements for Special Dipping and Coating Operations (Dip Tanks); Extension of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-09

...] Additional Requirements for Special Dipping and Coating Operations (Dip Tanks); Extension of the Office of Management and Budget's Approval of the Information Collection (Paperwork) Requirement AGENCY: Occupational... requirement specified in its Standard on Dipping and Coating Operations (Dip Tanks) (29 CFR 1910.126(g)(4...

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

PubMed

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Metallurgical investigation into ductility dip cracking in nickel based alloys

NASA Astrophysics Data System (ADS)

Noecker, Fredrick F., II

A690 is a Ni-Cr-Fe alloy with excellent resistance to general corrosion, localized corrosion and stress corrosion cracking. However, the companion filler metal for A690, EN52, has been shown by several researchers to be susceptible to ductility dip cracking (DDC), which limits its widespread use in joining applications. The Gleeble hot ductility test was used to evaluate the DDC susceptibility of A600 and A690, along with their filler metals, EN82H and EN52, throughout the heating and cooling portions of a simulated weld reheat thermal cycle. Both macroscopic mechanical measures and microscopic measures of DDC were quantified and compared. Water quenching was conducted at select temperatures for subsequent microstructural characterization. Microstructural and microchemical characterization was carried out using scanning electron microscopy, transmission electron microscopy and analytical electron microscopy (AEM) techniques. The greatest resistance to DDC was observed in A600 and A690 during heating, where no DDC cracks formed even when the samples were fractured. Both A690 and EN52 were found to form an intermediate on-cooling dip in ductility and UTS, which corresponded to an increase in ductility dip crack length. The hot ductility and cracking resistance of EN82H remained high throughout the entire thermal cycle. DDC susceptibility in both EN52 and EN82H decreased when the thermal cycle was modified to promote coarsening/precipitation of intergranular carbides prior to straining. AEM analysis did not reveal any sulfur or phosphorous intergranular segregation in EN52 at 1600°F on-heating, on-cooling or after a 60 second hold. The ductility dip cracks were preferentially oriented at a 45° to the tensile axis and were of a wedge type appearance, both of which are characteristic of grain boundary sliding (GBS). Samples with microstructures that consisted of coarsened carbides and/or serrated grain boundaries, which are expected to decrease GBS, were found to be

Mineralogical Evidence of Galvanic Corrosion in Domestic, Drinking Water Pipes

EPA Science Inventory

Drinking water distribution system (DWDS) piping contains numerous examples of galvanically-coupled metals (e.g., soldered copper pipe joints, copper-lead pipes joined during partial replacements of lead service lines). The possible role of galvanic corrosion in the release of l...

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

PubMed

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.

76 FR 55031 - Galvanized Steel Wire From the People's Republic of China: Preliminary Affirmative Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-06

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-976] Galvanized Steel Wire From... galvanized steel wire (galvanized wire) from the People's Republic of China (PRC). For information on the..., filed in proper form, concerning imports of galvanized wire from the PRC.\\1\\ The Department initiated a...

Ultrasonic dip seal maintenance system

DOEpatents

Poindexter, Allan M.; Ricks, Herbert E.

1978-01-01

A system for removing impurities from the surfaces of liquid dip seals and or wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities.

Concentrations and sources of cadmium, copper, lead and zinc in house dust in Christchurch, New Zealand.

PubMed

Kim, N; Fergusson, J

1993-09-30

The amounts (microgram m-2) and concentrations (microgram g-1) of cadmium, copper, lead and zinc have been measured in house dust in Christchurch, New Zealand. For 120 houses surveyed the geometric mean concentrations of the four metals are 4.24 micrograms g-1, 165 micrograms g-1, 573 micrograms g-1 and 10,400 micrograms g-1, respectively. In addition eleven variables, such as house age, carpet wear and traffic density, were recorded for each property and the results analysed with respect to their effects on the amounts and concentrations of the four elements. The amounts of all the metals were highly correlated with the overall dustiness of the houses, which was found to be predominantly determined by the degree of carpet wear. No one dominant source of cadmium was identified, although several minor sources including carpet wear, galvanized iron roofs and red/orange/yellow coloured carpets were implicated. Petrol lead and lead-based paints were identified as significant sources of lead in house dust. Rubber carpet underlays or backings were identified as a significant source of zinc, with some contribution from galvanized iron roofs. Road traffic and probably the existence of a fire place appear to contribute to the copper levels.

Corrosion of galvanized transmission towers near the Colbert Steam Plant: data report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coleman, J.H.

1980-01-01

This report contains data relating power plant emissions and the thickness of the galvanized layers on 20 electric transmission towers near the Colbert Steam plant after 25 years of ambient exposure. In addition to the thickness of the galvanized layers, total exposure to SO/sub 2/ at each tower was estimated and relevant meteorological data were reported. These data may be useful in relating galvanized corrosion to power plant emissions.

Galvanic corrosion of nitinol under deaerated and aerated conditions.

PubMed

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.

"Hot spots" growth on single nanowire controlled by electric charge.

PubMed

Xi, Shaobo; Liu, Xuehua; He, Ting; Tian, Lei; Wang, Wenhui; Sun, Rui; He, Weina; Zhang, Xuetong; Zhang, Jinping; Ni, Weihai; Zhou, Xiaochun

2016-06-09

"Hot spots" - a kind of highly active site, which are usually composed of some unique units, such as defects, interfaces, catalyst particles or special structures - can determine the performance of nanomaterials. In this paper, we study a model system, i.e. "hot spots" on a single Ag nanowire in the galvanic replacement reaction (GRR), by dark-field microscopy. The research reveals that electric charge can be released by the formation reaction of AgCl, and consequently the electrochemical potential on Ag nanowire drops. The electric charge could induce the reduction of Ag(+) to form the "hot spots" on the nanowire during the GRR. The appearance probability of "hot spots" is almost even along the Ag nanowire, while it is slightly lower near the two ends. The spatial distance between adjacent "hot spots" is also controlled by the charge, and obeys a model based on Boltzmann distribution. In addition, the distance distribution here has an advantage in electron transfer and energy saving. Therefore, it's necessary to consider the functions of electric charge during the synthesis or application of nanomaterials.

The timing of galvanic vestibular stimulation affects responses to platform translation

NASA Technical Reports Server (NTRS)

Hlavacka, F.; Shupert, C. L.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

1999-01-01

We compared the effects of galvanic vestibular stimulation applied at 0, 0.5, 1.5 and 2.5 s prior to a backward platform translation on postural responses. The effect of the galvanic stimulation was largest on the final equilibrium position of the center of pressure (CoP). The largest effects occurred for the 0.5 and 0-s pre-period, when the dynamic CoP pressure changes in response to both the galvanic stimulus and the platform translation coincided. The shift in the final equilibrium position was also larger than the sum of the shifts for the galvanic stimulus and the platform translation alone for the 0.5 and 0-s pre-periods. The initial rate of change of the CoP response to the platform translation was not significantly affected in any condition. Changes in the peak CoP position could be accounted for by local interaction of CoP velocity changes induced by the galvanic and translation responses alone, but the changes in final equilibrium position could only be accounted for by a change in global body orientation. These findings suggest that the contribution of vestibulospinal information is greatest during the dynamic phase of the postural response, and that the vestibular system contributes most to the later components of the postural response, particularly to the final equilibrium position. These findings suggest that a nonlinear interaction between the vestibular signal induced by the galvanic current and the sensory stimuli produced by the platform translation occurs when the two stimuli are presented within 1 s, during the dynamic phase of the postural response to the galvanic stimulus. When presented at greater separations in time, the stimuli appear to be treated as independent events, such that no interaction occurs. Copyright 1999 Elsevier Science B.V.

76 FR 19382 - Galvanized Steel Wire From China and Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-07

...)] Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission. ACTION... galvanized steel wire, provided for in subheading 7217.20.30 and 7217.20.45 of the Harmonized Tariff Schedule... investigations are being instituted in response to a petition filed on March 31, 2011, by Davis Wire Corp...

Energy and Process Optimization and Benchmarking of Army Industrial Processes

DTIC Science & Technology

2006-09-01

casting is a metal part formed by pouring molten iron, steel, aluminum, zinc , titanium, magnesium, copper, brass, bronze or cobalt, in nearly all...blanketing techniques. The loss of high-priced alloys is also mini- mized, while slag or dross rates are cut in half to help decrease disposal costs...fabricated of iron and steel; hot dip coating such items with aluminum, lead, or zinc ; retin- ning cans and utensils; (3) engraving, chasing and

76 FR 29266 - Galvanized Steel Wire From China and Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

...)] Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1\\ developed in the... reason of imports from China and Mexico of galvanized steel wire, provided for in subheading 7217.20.30... March 31, 2011, a petition was filed with the Commission and Commerce by Davis Wire Corporation...

Structure and Stoichiometry of MgxZny in Hot-Dipped Zn-Mg-Al Coating Layer on Interstitial-Free Steel

NASA Astrophysics Data System (ADS)

Kim, Jaenam; Lee, Chongsoo; Jin, Youngsool

2018-03-01

Correlations of stoichiometry and phase structure of MgxZny in hot-dipped Zn-Mg-Al coating layer which were modified by additive element have been established on the bases of diffraction and phase transformation principles. X-ray diffraction (XRD) results showed that MgxZny in the Zn-Mg-Al coating layers consist of Mg2Zn11 and MgZn2. The additive elements had a significant effect on the phase fraction of Mg2Zn11 while the Mg/Al ratio had a negligible effect. Transmission electron microscope (TEM) assisted selected area electron diffraction (SAED) results of small areas MgxZny were indexed dominantly as MgZn2 which have different Mg/Zn stoichiometry between 0.10 and 0.18. It is assumed that the MgxZny have deviated stoichiometry of the phase structure with additive element. The deviated Mg2Zn11 phase structure was interpreted as base-centered orthorhombic by applying two theoretical validity: a structure factor rule explained why the base-centered orthorhombic Mg2Zn11 has less reciprocal lattice reflections in the SAED compared to hexagonal MgZn2, and a phase transformation model elucidated its reasonable lattice point sharing of the corresponding unit cell during hexagonal MgZn2 (a, b = 0.5252 nm, c = 0.8577 nm) transform to intermediate tetragonal and final base-centered orthorhombic Mg2Zn11 (a = 0.8575 nm, b = 0.8874 nm, c = 0.8771 nm) in the equilibrium state.

KIC 8462852 optical dipping event

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2017-05-01

T. Boyajian (Louisiana State University) et al. reported in ATel #10405 that an optical dip is underway in KIC 8462852 (Boyajian's Star, Tabby's Star) beginning on 2017 May 18 UT. Tentative signs of small dips had been seen beginning April 24, and enhanced monitoring had begun at once at Fairborn Observatory (Tennessee State University). Photometry and spectroscopy from there on May 18 and 19 UT showed a dip underway. Cousins V photometry showed a drop of 0.02 magnitude, the largest dip (and the first clear one) seen in more than a year of monitoring. AAVSO observer Bruce Gary (GBL, Hereford, AZ) carried out V photometry which showed a fading from 11.906 V ± 0.004 to 11.9244 V ± 0.0033 between UT 2017 May 14 and May 19, a drop of 1.7%. Swift/UVOT observations obtained May 18 15:19 did not show a statistically significant drop in v, but Gary's photometry is given more weight. r'-band observations from Las Cumbres Observatory obtained 2017 May 17 to May 19 showed a 2% dip. Spectra by I. Steele (Liverpool JMU) et al. taken on 2017 May 20 with the 2.0 meter Liverpool Telescope, La Palma, showed no differences in the source compared to a reference spectrum taken 2016 July 4 when the system was not undergoing a dip (ATel #10406).Dips typically last for a few days, and larger dips can last over a week. It is not clear that this dip is over. Precision time-series V photometry is urgently requested from AAVSO observers, although all photometry is welcome. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). See full Alert Notice for more details. KIC 8462852 was the subject of AAVSO Alert Notices 532 and 542. See also Boyajian et al. 2016, also available as a preprint (http://arxiv.org/abs/1509.03622). General information about KIC 8462852 may be found at http://www.wherestheflux.com/.

76 FR 68422 - Galvanized Steel Wire From Mexico: Preliminary Determination of Sales at Less Than Fair Value and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-04

... DEPARTMENT OF COMMERCE International Trade Administration [A-201-840] Galvanized Steel Wire From... determines that galvanized steel wire (galvanized wire) from Mexico is being, or is likely to be, sold in the... investigation on galvanized wire from Mexico. See Galvanized Steel Wire from the People's Republic of China and...

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

PubMed

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 < 2.5 and chloride concentrations at least 11 times higher than bulk water levels. Waters with relatively high chloride tend to sustain high 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.

PRDM9 variation strongly influences recombination hot-spot activity and meiotic instability in humans.

PubMed

Berg, Ingrid L; Neumann, Rita; Lam, Kwan-Wood G; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A; Jeffreys, Alec J

2010-10-01

PRDM9 has recently been identified as a likely trans regulator of meiotic recombination hot spots in humans and mice. PRDM9 contains a zinc finger array that, in humans, can recognize a short sequence motif associated with hot spots, with binding to this motif possibly triggering hot-spot activity via chromatin remodeling. We now report that human genetic variation at the PRDM9 locus has a strong effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Subtle changes within the zinc finger array can create hot-spot nonactivating or enhancing variants and can even trigger the appearance of a new hot spot, suggesting that PRDM9 is a major global regulator of hot spots in humans. Variation at the PRDM9 locus also influences aspects of genome instability-specifically, a megabase-scale rearrangement underlying two genomic disorders as well as minisatellite instability-implicating PRDM9 as a risk factor for some pathological genome rearrangements.

PRDM9 variation strongly influences recombination hot-spot activity and meiotic instability in humans

PubMed Central

Berg, Ingrid L.; Neumann, Rita; Lam, Kwan-Wood G.; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A.; Jeffreys, Alec J.

2011-01-01

PRDM9 has recently been identified as a likely trans-regulator of meiotic recombination hot spots in humans and mice1-3. The protein contains a zinc finger array that in humans can recognise a short sequence motif associated with hot spots4, with binding to this motif possibly triggering hot-spot activity via chromatin remodelling5. We now show that variation in the zinc finger array in humans has a profound effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Very subtle changes within the array can create hot-spot non-activating and enhancing alleles, and even trigger the appearance of a new hot spot. PRDM9 thus appears to be the preeminent global regulator of hot spots in humans. Variation at this locus also influences aspects of genome instability, specifically a megabase-scale rearrangement underlying two genomic disorders6 as well as minisatellite instability7, implicating PRDM9 as a risk factor for some pathological genome rearrangements. PMID:20818382

Iterative dip-steering median filter

NASA Astrophysics Data System (ADS)

Huo, Shoudong; Zhu, Weihong; Shi, Taikun

2017-09-01

Seismic data are always contaminated with high noise components, which present processing challenges especially for signal preservation and its true amplitude response. This paper deals with an extension of the conventional median filter, which is widely used in random noise attenuation. It is known that the standard median filter works well with laterally aligned coherent events but cannot handle steep events, especially events with conflicting dips. In this paper, an iterative dip-steering median filter is proposed for the attenuation of random noise in the presence of multiple dips. The filter first identifies the dominant dips inside an optimized processing window by a Fourier-radial transform in the frequency-wavenumber domain. The optimum size of the processing window depends on the intensity of random noise that needs to be attenuated and the amount of signal to be preserved. It then applies median filter along the dominant dip and retains the signals. Iterations are adopted to process the residual signals along the remaining dominant dips in a descending sequence, until all signals have been retained. The method is tested by both synthetic and field data gathers and also compared with the commonly used f-k least squares de-noising and f-x deconvolution.

76 FR 33242 - Galvanized Steel Wire From the People's Republic of China: Postponement of Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-08

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-976] Galvanized Steel Wire From... the countervailing duty investigation of galvanized steel wire from the People's Republic of China. See Galvanized Steel Wire From the People's Republic of China: Initiation of Countervailing Duty...

24 CFR 3280.703 - Minimum standards.

Code of Federal Regulations, 2012 CFR

2012-04-01

.../ASME B1.20.1-1983. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Nonferrous Pipe... 1997 revisions. Ferrous Pipe and Fittings Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Standard Specification for Electric-Resistance-Welded...

24 CFR 3280.703 - Minimum standards.

Code of Federal Regulations, 2010 CFR

2010-04-01

.../ASME B1.20.1-1983. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Nonferrous Pipe... 1997 revisions. Ferrous Pipe and Fittings Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Standard Specification for Electric-Resistance-Welded...

24 CFR 3280.604 - Materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Pipe Threads, General Purpose (Inch... Seamless Copper Pipe, Standard Sizes—ASTM B42-93. Standard Specification for General Requirements for...

24 CFR 3280.604 - Materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Pipe Threads, General Purpose (Inch... Seamless Copper Pipe, Standard Sizes—ASTM B42-93. Standard Specification for General Requirements for...

24 CFR 3280.604 - Materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Pipe Threads, General Purpose (Inch... Seamless Copper Pipe, Standard Sizes—ASTM B42-93. Standard Specification for General Requirements for...

24 CFR 3280.703 - Minimum standards.

Code of Federal Regulations, 2011 CFR

2011-04-01

.../ASME B1.20.1-1983. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Nonferrous Pipe... 1997 revisions. Ferrous Pipe and Fittings Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Standard Specification for Electric-Resistance-Welded...

24 CFR 3280.703 - Minimum standards.

Code of Federal Regulations, 2013 CFR

2013-04-01

.../ASME B1.20.1-1983. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Nonferrous Pipe... 1997 revisions. Ferrous Pipe and Fittings Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Standard Specification for Electric-Resistance-Welded...

Coating Galvanized Steel

DTIC Science & Technology

1989-06-01

bonding of topcoats to smooth galvanizing have lead to such practices as washing with vinegar , washing with copper sulfate solution, or weathering before...of special treatments other than weathering: "The "home cure" type of treatments such as washing the surface with vinegar , acetic acid, cider, copper... alcohol . The wash primer used was MIL-P-15328 (Formula 117). It is spray- applied to give 0.3- to 0.5-mil dry film thickness and is used on ships to

9 CFR 72.25 - Dipping methods.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Dipping methods. 72.25 Section 72.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Dipping methods. Dipping is accomplished by thoroughly wetting the entire skin by either immersion in a...

9 CFR 72.25 - Dipping methods.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Dipping methods. 72.25 Section 72.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... CATTLE § 72.25 Dipping methods. Dipping is accomplished by thoroughly wetting the entire skin by either...

9 CFR 72.25 - Dipping methods.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Dipping methods. 72.25 Section 72.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... CATTLE § 72.25 Dipping methods. Dipping is accomplished by thoroughly wetting the entire skin by either...

9 CFR 72.25 - Dipping methods.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Dipping methods. 72.25 Section 72.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... CATTLE § 72.25 Dipping methods. Dipping is accomplished by thoroughly wetting the entire skin by either...

9 CFR 72.25 - Dipping methods.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Dipping methods. 72.25 Section 72.25 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... CATTLE § 72.25 Dipping methods. Dipping is accomplished by thoroughly wetting the entire skin by either...

Thermodynamic modelling of the formation of zinc-manganese ferrite spinel in electric arc furnace dust.

PubMed

Pickles, C A

2010-07-15

Electric arc furnace dust is generated when automobile scrap, containing galvanized steel, is remelted in an electric arc furnace. This dust is considered as a hazardous waste in most countries. Zinc is a major component of the dust and can be of significant commercial value. Typically, the majority of the zinc exists as zinc oxide (ZnO) and as a zinc-manganese ferrite spinel ((Zn(x)Mn(y)Fe(1-x-y))Fe(2)O(4)). The recovery of the zinc from the dust in metal recycling and recovery processes, particularly in the hydrometallurgical extraction processes, is often hindered by the presence of the mixed ferrite spinel. However, there is a paucity of information available in the literature on the formation of this spinel. Therefore, in the present research, the equilibrium module of HSC Chemistry 6.1 was utilized to investigate the thermodynamics of the formation of the spinel and the effect of variables on the amount and the composition of the mixed ferrite spinel. It is proposed that the mixed ferrite spinel forms due to the reaction of iron-manganese particulates with both gaseous oxygen and zinc, at the high temperatures in the freeboard of the furnace above the steel melt. Based on the thermodynamic predictions, methods are proposed for minimizing the formation of the mixed ferrite spinel. 2010 Elsevier B.V. All rights reserved.

77 FR 17418 - Galvanized Steel Wire From the People's Republic of China: Final Affirmative Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-976] Galvanized Steel Wire From... exporters of galvanized steel wire (galvanized wire) from the People's Republic of China (the PRC). For... investigation are Davis Wire Corporation, Johnstown Wire Technologies, Inc., Mid- South Wire Company, Inc...

A microfluidic galvanic cell on a single layer of paper

NASA Astrophysics Data System (ADS)

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.

76 FR 73589 - Galvanized Steel Wire From the People's Republic of China: Amended Preliminary Determination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-975] Galvanized Steel Wire From... galvanized steel wire from the People's Republic of China (``PRC'').\\1\\ We are amending our Preliminary... Fair Value and Postponement of Final Determination: Galvanized Steel Wire from the People's Republic of...

24 CFR 3280.703 - Minimum standards.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines—ASTM A539-1999. Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1-1983. Welding and Seamless Wrought...

Nd:YAG laser welding of coated sheet steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graham, M.P.; Kerr, H.W.; Weckman, D.C.

1994-12-31

Coated sheet steels are used extensively in the automotive industry for the fabrication of automobile body components; however, their reduced weldability by the traditional welding processes has led to numerous studies into the use of alternate process such as laser welding. In this paper, we present a modified joint geometry which allows high quality lap welds of coated sheet steels to be made by laser welding processes. Hot-dipped galvanized sheet (16 gauge), with a 60 g/m zinc coating was used in this study. A groove was created in the top sheet of a specimen pair by pressing piano wires ofmore » various diameters into the sheet. The specimens were clamped together in a lag-joint configuration such that they were in contacted only along the grove projection. A parametric study was conducted using the variables of welding speed, laser mean power (685 W, 1000 W and 1350 W), and grove size. Weld quality and weld pool dimensions were assessed using metallurgical cross-sections and image analysis techniques. Acceptable quality seam welds were produced in the galvanized sheet steel with both grove sizes when using 1000 W and 1350 W laser mean powers and a range of welding speeds. Results of the shear-tensile tests showed that high loads to failure, with failure occurring in the parent material, were predominately found in welds produced at speeds over 1.2 m/min and when using the high mean laser powers: 1000 W and 1350 W. A modified lap joint geometry, in which a groove is pre-placed in the top sheet of the lap-joint configuration, has been developed which permits laser welding of coated sheet steels. Good quality seam welds have been produced in 16 gauge galvanized sheet steels at speeds up to 2.7 m/min using a 2 kW CW Nd:YAG laser operating at 1350 W laser mean power. Weld quality was not affected by changes in groove size.« less

77 FR 17427 - Notice of Final Determination of Sales at Less Than Fair Value: Galvanized Steel Wire From Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... Determination of Sales at Less Than Fair Value: Galvanized Steel Wire From Mexico AGENCY: Import Administration... the investigation of sales at less than fair value of galvanized steel wire (galvanized wire) from Mexico.\\1\\ \\1\\ See Galvanized Steel Wire from Mexico: Preliminary Determination of Sales at Less Than...

24 CFR 3280.604 - Materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Material and Property Standard for Special Cast Iron Fittings—IAPMO PS 5-84. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1-1983...

An analysis of variable dissolution rates of sacrificial zinc anodes: a case study of the Hamble estuary, UK.

PubMed

Rees, Aldous B; Gallagher, Anthony; Comber, Sean; Wright, Laurence A

2017-09-01

Sacrificial anodes are intrinsic to the protection of boats and marine structures by preventing the corrosion of metals higher up the galvanic scale through their preferential breakdown. The dissolution of anodes directly inputs component metals into local receiving waters, with variable rates of dissolution evident in coastal and estuarine environments. With recent changes to the Environmental Quality Standard (EQS), the load for zinc in estuaries such as the Hamble, UK, which has a large amount of recreational craft, now exceeds the zinc standard of 7.9 μg/l. A survey of boat owners determined corrosion rates and estimated zinc loading at between 6.95 and 7.11 t/year. The research confirms the variable anode corrosion within the Hamble and highlighted a lack of awareness of anode technology among boat owners. Monitoring and investigation discounted metal structures and subterranean power cables as being responsible for these variations but instead linked accelerated dissolution to marina power supplies and estuarine salinity variations.

Liquid sodium dip seal maintenance system

DOEpatents

Briggs, Richard L.; Meacham, Sterling A.

1980-01-01

A system for spraying liquid sodium onto impurities associated with liquid dip seals of nuclear reactors. The liquid sodium mixing with the impurities dissolves the impurities in the liquid sodium. The liquid sodium having dissolved and diluted the impurities carries the impurities away from the site thereby cleaning the liquid dip seal and surrounding area. The system also allows wetting of the metallic surfaces of the dip seal thereby reducing migration of radioactive particles across the wetted boundary.

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

NASA Astrophysics Data System (ADS)

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.

Two-colour dip spectroscopy of jet-cooled molecules

NASA Astrophysics Data System (ADS)

Ito, Mitsuo

In optical-optical double resonance spectroscopy, the resonance transition from an intermediate state to a final state can be detected by a dip of the signal (fluorescence or ion) associated with the intermediate state. This method probing the signal of the intermediate state may be called `two-colour dip spectroscopy'. Various kinds of two-colour dip spectroscopy such as two-colour fluorescence/ion dip spectroscopy, two-colour ionization dip spectroscopy employing stimulated emission, population labelling spectroscopy and mass-selected ion dip spectroscopy with dissociation were briefly described, paying special attention to their characteristics in excitation, detection and application. They were extensively and successfully applied to jet-cooled large molecules and provided us with new useful information on the energy and dynamics of excited molecules.

Large Capacity SMES for Voltage Dip Compensation

NASA Astrophysics Data System (ADS)

Iwatani, Yu; Saito, Fusao; Ito, Toshinobu; Shimada, Mamoru; Ishida, Satoshi; Shimanuki, Yoshio

Voltage dips of power grids due to thunderbolts, snow damage, and so on, cause serious damage to production lines of precision instruments, for example, semiconductors. In recent years, in order to solve this problem, uninterruptible power supply systems (UPS) are used. UPS, however, has small capacity, so a great number of UPS are needed in large factories. Therefore, we have manufactured the superconducting magnetic energy storage (SMES) system for voltage dip compensation able to protect loads with large capacity collectively. SMES has advantages such as space conservation, long lifetime and others. In field tests, cooperating with CHUBU Electric Power Co., Inc. we proved that SMES is valuable for compensating voltage dips. Since 2007, 10MVA SMES improved from field test machines has been running in a domestic liquid crystal display plant, and in 2008, it protected plant loads from a number of voltage dips. In this paper, we report the action principle and components of the improved SMES for voltage dip compensation, and examples of waveforms when 10MVA SMES compensated voltage dips.

The Effect of Bi on the Selective Oxide Formation on CMnSi TRIP Steel

NASA Astrophysics Data System (ADS)

Oh, Jonghan; Cho, Lawrence; Kim, Myungsoo; Kang, Kichul; De Cooman, Bruno C.

2016-11-01

The effect of Bi addition on the selective oxidation and the galvanizability of CMnSi transformation-induced plasticity (TRIP) steels was studied by hot dip galvanizing laboratory simulations. Bi-added TRIP steels were intercritically annealed at 1093 K (820 °C) and galvanized in a 0.22 wt pct Al-containing Zn bath. The oxide morphology was investigated by scanning electron microscopy, transmission electron microscopy, and 3D atom probe tomography. Bi formed a Bi-enriched surface layer during the intercritical annealing. A decrease of the oxygen permeability was observed with increasing Bi addition. The internal oxidation was suppressed in Bi-added CMnSi TRIP steel. The surface oxide morphology was changed from a continuous layer morphology to a more lens-shaped morphology. The galvanizability of the Bi-added TRIP steel was improved by the combination of the change of the oxide morphology and the dissolution of the Bi-enriched surface layer during immersion of the strip in the Zn bath.

9 CFR 72.13 - Permitted dips and procedures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Administrator, APHIS. Before a dip will be specifically approved as a permitted dip for the eradication of ticks... effectually eradicate ticks without injury to the animals dipped. (d) Tissue residues; restriction on...

On the possibility to grow zinc oxide-based transparent conducting oxide films by hot-wire chemical vapor deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abrutis, Adulfas, E-mail: adulfas.abrutis@chf.vu.lt; Silimavicus, Laimis; Kubilius, Virgaudas

Hot-wire chemical vapor deposition (HW-CVD) was applied to grow zinc oxide (ZnO)-based transparent conducting oxide (TCO) films. Indium (In)-doped ZnO films were deposited using a cold wall pulsed liquid injection CVD system with three nichrome wires installed at a distance of 2 cm from the substrate holder. The wires were heated by an AC current in the range of 0–10 A. Zn and In 2,2,6,6-tetramethyl-3,5-heptanedionates dissolved in 1,2-dimethoxyethane were used as precursors. The hot wires had a marked effect on the growth rates of ZnO, In-doped ZnO, and In{sub 2}O{sub 3} films; at a current of 6–10 A, growth rates weremore » increased by a factor of ≈10–20 compared with those of traditional CVD at the same substrate temperature (400 °C). In-doped ZnO films with thickness of ≈150 nm deposited on sapphire-R grown at a wire current of 9 A exhibited a resistivity of ≈2 × 10{sup −3} Ωcm and transparency of >90% in the visible spectral range. These initial results reveal the potential of HW-CVD for the growth of TCOs.« less

Effect of Continuous Galvanizing Heat Treatments on the Microstructure and Mechanical Properties of High Al-Low Si Transformation Induced Plasticity Steels

NASA Astrophysics Data System (ADS)

Bellhouse, E. M.; McDermid, J. R.

2010-02-01

Heat treatments were performed using an isothermal bainitic transformation (IBT) temperature compatible with continuous hot-dip galvanizing on two high Al-low Si transformation induced plasticity (TRIP)-assisted steels. Both steels had 0.2 wt pct C and 1.5 wt pct Mn; one had 1.5 wt pct Al and the other had 1 wt pct Al and 0.5 wt pct Si. Two different intercritical annealing (IA) temperatures were used, resulting in intercritical microstructures of 50 pct ferrite (α)-50 pct austenite (γ) and 65 pct α-35 pct γ. Using the IBT temperature of 465 °C, five IBT times were tested: 4, 30, 60, 90, and 120 seconds. Increasing the IBT time resulted in a decrease in the ultimate tensile strength (UTS) and an increase in the uniform elongation, yield strength, and yield point elongation. The uniform elongation was higher when using the 50 pct α-50 pct γ IA temperature when compared to the 65 pct α-35 pct γ IA temperature. The best combinations of strength and ductility and their corresponding heat treatments were as follows: a tensile strength of 895 MPa and uniform elongation of 0.26 for the 1.5 pct Al TRIP steel at the 50 pct γ IA temperature and 90-second IBT time; a tensile strength of 880 MPa and uniform elongation of 0.27 for the 1.5 pct Al TRIP steel at the 50 pct γ IA temperature and 120-second IBT time; and a tensile strength of 1009 MPa and uniform elongation of 0.22 for the 1 pct Al-0.5 pct Si TRIP steel at the 50 pct γ IA temperature and 120-second IBT time.

Prognostic investigation of galvanic corrosion precursors in aircraft structures and their detection strategy

NASA Astrophysics Data System (ADS)

James, Robin; Kim, Tae Hee; Narayanan, Ram M.

2017-04-01

Aluminum alloys have been the dominant materials for aerospace construction in the past fifty years due to their light weight, forming and alloying, and relative low cost in comparison to titanium and composites. However, in recent years, carbon fiber reinforced polymers (CFRPs) and honeycomb materials have been used in aircrafts in the quest to attain lower weight, high temperature resistance, and better fuel efficiency. When these two materials are coupled together, the structural strength of the aircraft is unparalleled, but this comes at a price, namely galvanic corrosion. Previous experimental results have shown that when CFRP composite materials are joined with high strength aluminum alloys (AA7075-T6 or AA2024-T3), galvanic corrosion occurs at the material interfaces, and the aluminum is in greater danger of corroding, particularly since carbon and aluminum are on the opposite ends of the galvanic series. In this paper, we explore the occurrence of the recognizable precursors of galvanic corrosion when CFRP plate is coupled to an aluminum alloy using SS-304 bolts and exposed to environmental degradation, which creates significant concerns for aircraft structural reliability. The galvanic corrosion software package, BEASY, is used to simulate the growth of corrosion in the designed specimen after which a microwave non-destructive testing (NDT) technique is explored to detect corrosion defects that appear at the interface of this galvanic couple. This paper also explores a loaded waveguide technique to determine the dielectric constant of the final corrosion product at the Q-band millimeter-wave frequency range (33-50 GHz), as this can be an invaluable asset in developing early detection strategies.

Investigation of galvanic corrosion in laser-welded stainless steel sheets

NASA Astrophysics Data System (ADS)

Kwok, Chi-Tat; Fong, Siu Lung; Cheng, Fai Tsun; Man, Hau-Chung

2004-10-01

In the present study, bead-on-plate specimens of 1-mm sheets of austenitic and duplex stainless steels were fabricated by laser penetration welding with a 2.5-kW CW Nd:YAG laser. The galvanic corrosion behavior of laser-weldment (LW) against as-received (AR) specimens with an area rato of 1:1 in 3.5% NaCL solution was studied by means of a zero-resistance ammeter. The free corrosion potentials of as-received specimens were found to be considerably higher than those of laser weldments, indicating that the weldments are more active and always act as anodes. The ranking of galvanic current densities (IG) of the couples in ascending order is: AR S31603-LW S31603 < AR S31803-LW S31803 < AR S32760-LW S32760 < AR S30400-LW S30400. For the galvanic couple between AR S30400 and LW S30400, the IG is the highest (78.6 nA/cm2) because large amount of δ-ferrite in the weld zone acts as active sites. On the other hand, the IG of the galvanic couple between AR S31603 and LW S31603 is the lowest (-26 nA/cm2) because no δ-ferrite is present after laser welding. The recorded IG of all couples revealed constantly low values (in the rnage of nA/cm2) and sometimes stayed negative, which indicated polarity reversal.

Zinc coated sheet steel for press hardening

NASA Astrophysics Data System (ADS)

Ghanbari, Zahra N.

Galvanized steels are of interest to enhance corrosion resistance of press-hardened steels, but concerns related to liquid metal embrittlement have been raised. The objective of this study was to assess the soak time and temperature conditions relevant to the hot-stamping process during which Zn penetration did or did not occur in galvanized 22MnB5 press-hardening steel. A GleebleRTM 3500 was used to heat treat samples using hold times and temperatures similar to those used in industrial hot-stamping. Deformation at both elevated temperature and room temperature were conducted to assess the coating and substrate behavior related to forming (at high temperature) and service (at room temperature). The extent of alloying between the coating and substrate was assessed on undeformed samples heat treated under similar conditions to the deformed samples. The coating transitioned from an α + Gamma1 composition to an α (bcc Fe-Zn) phase with increased soak time. This transition likely corresponded to a decrease in availability of Zn-rich liquid in the coating during elevated temperature deformation. Penetration of Zn into the substrate sheet in the undeformed condition was not observed for any of the processing conditions examined. The number and depth of cracks in the coating and substrate steel was also measured in the hot-ductility samples. The number of cracks appeared to increase, while the depth of cracks appeared to decrease, with increasing soak time and increasing soak temperature. The crack depth appeared to be minimized in the sample soaked at the highest soak temperature (900 °C) for intermediate and extended soak times (300 s or 600 s). Zn penetration into the substrate steel was observed in the hot-ductility samples soaked at each hold temperature for the shortest soak time (10 s) before being deformed at elevated temperature. Reduction of area and elongation measurements showed that the coated sample soaked at the highest temperature and longest soak time

Surface and cut-edge corrosion behavior of Zn-Mg-Al alloy-coated steel sheets as a function of the alloy coating microstructure

NASA Astrophysics Data System (ADS)

Oh, Min-Suk; Kim, Sang-Heon; Kim, Jong-Sang; Lee, Jae-Won; Shon, Je-Ha; Jin, Young-Sool

2016-01-01

The effects of Mg and Al content on the microstructure and corrosion resistance of hot-dip Zn-Mg-Al alloycoated steel sheets were investigated. Pure Zn and Zn-based alloy coatings containing Mg (0-5 wt%) and Al (0.2-55 wt%) were produced by a hot-dip galvanizing method. Mg and Al addition induced formation of intermetallic microstructures, like primary Zn, Zn/MgZn2 binary eutectic, dendric Zn/Al eutectoid, and Zn/Al/MgZn2/ternary eutectic structures in the coating layer. MgZn2-related structures (Zn/MgZn2, Zn/Al/MgZn2, MgZn2) played an important role in increasing the corrosion resistance of Zn-Mg-Al alloy-coated steel sheets. Zn-3%Mg-2.5%Al coating layer containing a large volume of lamellar-shaped Zn/MgZn2 binary eutectic structures showed the best cut-edge corrosion resistance. The analysis indicated that Mg dissolved from MgZn2 in the early stage of corrosion and migrated to the cathodic region of steel-exposed cut-edge area to form dense and ordered protective corrosion products, leading to prolonged cathodic protection of Zn-Mg-Al alloy-coated steel sheets.

Origin of Dips in 4U1915-05

NASA Technical Reports Server (NTRS)

Grindlay, Jonathan E.

2003-01-01

This grant supported our participation in a proposal submitted by Didier Barret to conduct a study of the dipping LMXB 4U1915-05. In this Final Report, we summarize the Scientific Objectives of this investigation and the results achieved. Data analysis is still in progress and publication of results will be forthcoming.Our objectives in this work have been to study: 1. Spectra of dips in 4 Ul916-05: This low mass x-ray binary (LMXB) is a 50min binary system and the first to show x-ray dip behaviour. Our XMM observation was proposed to study the x-ray spectra of the dips to better constrain their physical properties. Of primary interest is the variation of the absorbing column density as a function of flux in the dip. We wish to isolate the absorption from Compton scattering components in the dip spectra, and to use the large throughput of XMM to better constrain short timescale variations of the spectrum in the dips. 2. Period of the dips and long-term ephemeris: We also seek to improve upon the long- term ephemeris of the dips by combining these more recent XMM data with earlier RXTE data to update the ephemeris for dips and the determination of the dip period to further test whether the dip period represents the true binary period of this LMXB. We shall extend the ephemeris published by Chou, Grindlay and Bloser 2001, ApJ, 549, 1135) to test the assertion of Retter, Chou et a1 2002, MNRAS, 330, 37 that the dips are indeed the binary period and not a precession period. 1 3 Results Achieved The observations for this program were delayed, presumably for reasons related to the general difficulty of scheduling XMM targets in this region moderately close to the Cygnus region. 4'171916-05 was finally observed (2lksec) on April 24, 2002, but the data have not been delivered. A second observation was conducted on September 9, 2002 (18ksec) and the data are still being analyzed. 4 Papers Presented and Published A paper is in preparation for Astronomy and Astrophysics in

Role of the DIP Molecules in DCC Signaling

DTIC Science & Technology

2001-03-01

DIP13 interacts with AKT , a key molecule for cell survival. Our results suggest that the DCC apoptotic signal is mediated by DIP13 that interferes with... AKT cell survival pathway, resulting in cell death. Finally, we have cloned DIP13 beta, suggesting that DIP13 represents a family of molecules with at...interacts with DCC through its PTB domain (Fig. 4). Interestingly, Mitsuuchi et al. (1999) identified a gene dubbed APPL that interacts with AKT , a key

[Contribution of Aleksander Sapieha (1773-1812) into European galvanization therapy].

PubMed

Gorski, P; Goetz, W

1996-01-01

For the development of the therapy using electricity as agent two tracks can be identified. On the one side, the indication for applying this therapy was handled more careful, simultaneously the technical equipment was improved. The Polish noble man Alexander Sapieha (1773-1812), the leading natural scientist of the Granddukedom of Warsaw, cooperated with excellent European scientists in order to improve the galvanic battery technologically. Among these scientists were Alexander Volta (1745-1827), the inventor of the battery, and Johann Bartholomaeus Trommsdorff (1770-1837), who is considered as one of the founders of scientific pharmacy in Europe. A. Sapieha supported the publication of galvanic experiences, e.g. in the case of Alexander of Humboldt (1769-1859) by publishing his paper about electric fishes. Sapiehas connections with the scientific centers in Turin and Bologna, Erfurt, Warszaw and Paris accelerated the exchange of information about galvanism. Later the resulting mini-batteries were employed in diathermie, in defibrillators and pacemakers. Details about these connections are presented in the lecture resp. full paper.

SERS activity studies of Ag/Au bimetallic films prepared by galvanic replacement

NASA Astrophysics Data System (ADS)

Wang, Chaonan; Fang, Jinghuai; Jin, Yonglong

2012-10-01

Ag films on Si substrates were fabricated by immersion plating, which served as sacrificial materials for preparation of Ag/Au bimetallic films by galvanic replacement method. SEM images displayed that the sacrificial Ag films presenting island morphology experienced interesting structural evolution process during galvanic replacement reaction, and nano-scaled holes were formed in the resultant bimetallic films. SERS measurements using crystal violet as an analyte showed that SERS intensities of bimetallic films were enhanced significantly compared with that of pure Ag films and related mechanisms were discussed. Immersion plating experiment carried out on Ag films on PEN substrates fabricated by photoinduced reduction method further confirmed that galvanic replacement is an easy method to fabricate Ag/Au bimetallic and a potential approach to improve the SERS performance of Ag films.

The mechanical properties and microstructures of vanadium bearing high strength dual phase steels processed with continuous galvanizing line simulations

NASA Astrophysics Data System (ADS)

Gong, Yu

For galvanized or galvannealed steels to be commercially successful, they must exhibit several attributes: (i) easy and inexpensive processing in the hot mill, cold mill and on the coating line, (ii) high strength with good formability and spot weldability, and (iii) good corrosion resistance. At the beginning of this thesis, compositions with a common base but containing various additions of V or Nb with or without high N were designed and subjected to Gleeble simulations of different galvanizing(GI), galvannealing(GA) and supercooling processing. The results revealed the phase balance was strongly influenced by the different microalloying additions, while the strengths of each phase were somewhat less affected. Our research revealed that the amount of austenite formed during intercritical annealing can be strongly influenced by the annealing temperature and the pre-annealing conditions of the hot band (coiling temperature) and cold band (% cold reduction). In the late part of this thesis, the base composition was a low carbon steel which would exhibit good spot weldability. To this steel were added two levels of Cr and Mo for strengthening the ferrite and increasing the hardenability of intercritically formed austenite. Also, these steels were produced with and without the addition of vanadium in an effort to further increase the strength. Since earlier studies revealed a relationship between the nature of the starting cold rolled microstructure and the response to CGL processing, the variables of hot band coiling temperature and level of cold reduction prior to annealing were also studied. Finally, in an effort to increase strength and ductility of both the final sheet (general formability) and the sheared edges of cold punched holes (local formability), a new thermal path was developed that replaced the conventional GI ferrite-martensite microstructure with a new ferrite-martensite-tempered martensite and retained austenite microstructure. The new

9 CFR 73.10 - Permitted dips; substances allowed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... follows: (1) Lime-sulphur dip, other than proprietary brands thereof, made in the proportion of 12 pounds of unslaked lime (or 16 pounds of commercial hydrated lime, not airslaked lime) and 24 pounds of... of lime-sulphur dip. (2) Dips made from specifically permitted proprietary brand emulsions of...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-25

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

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

PubMed

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

2016-09-08

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.

Evaluation of inorganic zinc-rich primers using Electrochemical Impedance Spectroscopy (EIS)

NASA Technical Reports Server (NTRS)

Calle, Luz M.

1993-01-01

This investigation explores the use of Electrochemical Impedance Spectroscopy (EIS) in combination with beach exposure as a short term method for analyzing the performance of twenty-one zinc-rich primers. The twenty-one zinc-rich primers were: Carboline CZ-11, Ameron Devoe-Marine Catha-Coat 304, Briner V-65, Ameron D-21-9, Sherwin Williams Zinc Clad II, Carboline CZ-D7, Ameron D-4, Dupont Ganicin 347WB, Porter TQ-4374H, Inorganic Coatings IC-531, Subox Galvanox IV, Southern Coatings Chemtec 600, Glidden Glidzinc 5530, Byco SP-101, Tnemec 90E-75, Devoe Catha-Coat 302H, Glidden Glidzinc 5536, Koppers 701, Ameron D-21-5, Coronado 935-152, and Subox Galvanoz V. Data were also collected on galvanized steel for comparison purposes. A library of Bode magnitude plots was generated for each coating including curves for the initial time and after each week of atmospheric exposure as Beach Corrosion Test Site near the Space Shuttle launch pad at the Kennedy Space Center for up to three weeks. An examination of the variation of the Bode magnitude plots with atmospheric exposure revealed no clearly identifiable trend at this point that could distinguish between the good and the poor coatings. The test will be continued by including EIS measurements after six months and one year of atmospheric exposure.

Imaging free zinc levels in vivo - what can be learned?

PubMed

De Leon-Rodriguez, Luis; Lubag, Angelo Josue M; Sherry, A Dean

2012-12-01

Our ever-expanding knowledge about the role of zinc in biology includes its role in redox modulation, immune response, neurotransmission, reproduction, diabetes, cancer, and Alzheimers disease is galvanizing interest in detecting and monitoring the various forms of Zn(II) in biological systems. This paper reviews reported strategies for detecting and tracking of labile or "free" unchelated Zn(II) in tissues. While different bound structural forms of Zn(II) have been identified and studied in vitro by multiple techniques, very few molecular imaging methods have successfully tracked the ion in vivo. A number of MRI and optical strategies have now been reported for detection of free Zn(II) in cells and tissues but only a few have been applied successfully in vivo. A recent report of a MRI sensor for in vivo tracking of Zn(II) released from pancreatic β-cells during insulin secretion exemplifies the promise of rational design of new Zn(II) sensors for tracking this biologically important ion in vivo. Such studies promise to provide new insights into zinc trafficking in vivo and the critical role of this ion in many human diseases.

Attenuation of pressure dips underneath piles of spherocylinders.

PubMed

Zhao, Haiyang; An, Xizhong; Gou, Dazhao; Zhao, Bo; Yang, Runyu

2018-05-30

The discrete element method (DEM) was used to simulate the piling of rod-like (elongated sphero-cylindrical) particles, mainly focusing on the effect of particle shape on the structural and force properties of the piles. In this work, rod-like particles of different aspect ratios were discharged on a flat surface to form wedge-shaped piles. The surface properties of the piles were characterized in terms of angle of repose and stress at the bottom of the piles. The results showed that the rise of the angle of repose became slower with the increase of particle aspect ratio. The pressure dip underneath the piles reached the maximum when the particle aspect ratio was around 1.6, beyond which the pressure dip phenomenon became attenuated. Both the pressure dip and the shear stress dip were quantitatively examined. The structure and forces inside the piles were further analyzed to understand the change in pressure dip, indicating that "bridging" or "arching" structures within the piles were the cause of the pressure dip.

Galvanic corrosion behaviors of Cu connected to Au on a printed circuit board in ammonia solution

NASA Astrophysics Data System (ADS)

Oh, SeKwon; Kim, YoungJun; Jung, KiMin; Park, MiSeok; Shon, MinYoung; Kwon, HyukSang

2018-01-01

During etching treatments of printed circuit board (PCB) with ammnioa solution, galvanic corrosion occurs between electrically connected gold and copper, and resulting in unexpected over-etching problems. Herein, we determine corrosion of galvanic coupled Cu to Au quantitatively in ammonia solutions, and evaluate factors influencing corrosion of galvanic coupled Cu to Au (i.e., area ratio of anode to cathode and stirring speed). The difference of the corrosion rate (Δi = icouple, (Cu-Au)-icorr, Cu) of Cu connected to Au (117 μA/cm2) and of single Cu (86 μA/cm2) infers the amount of over-etching of Cu resulting from galvanic corrosion in ammonia solution (Δi = 0.31 μA/cm2). As the stirring speed increases from 0 to 400 rpm, the corrosion rate of galvanic coupled Cu to Au increases from 36 to 191 μA/cm2. Furthermore, we confirm that an increase in the area ratio (Au/Cu) from 0.5 to 25 results in a higher rate of corrosion of Cu connected to Au. The corrosion rate of galvanic coupled Cu to Au is approximately 20 times higher when the area ratio of Au to Cu is 25 (1360 μA/cm2) than when the ratio is 0.5 (67 μA/cm2).

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

PubMed Central

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

Effectiveness of low-cost electromagnetic shielding using nail-together galvanized steel: Test results. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, P.F.; Kennedy, E.L.; McCormack, R.G.

1992-09-01

The sensitivity of modern electronic equipment has increased the need for costly electromagnetic shielding. To reduce this cost, the U.S. Army Construction Engineering Research Laboratories (USACERL) has developed a new concept for shielding design that uses 28-gauge galvanized steel and standard galvanized nails. In this study, an electromagnetically shielded structure using the concept was designed, built, and evaluated for shielding effectiveness. The galvanized material was mounted to the standard USACERL test aperture and nailed to the wooden module frame, and the shielding effectiveness of the new construction design was measured using radio frequency antennas and receivers. Evaluations showed that themore » nail-together structure proved adequate for many shielding applications. However, while the galvanized steel met most shielding application requirements, this process added multiple seams to the structure, which decreased shielding in many instances by as much as 40 dB. Electromagnetic shielding, Electromagnetic pulse C3I Facilities.« less

Galvanic Cells: Anodes, Cathodes, Signs and Charges

ERIC Educational Resources Information Center

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…

Galvanic vestibular stimulation speeds visual memory recall.

PubMed

Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

2008-08-01

The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

Galvanic corrosion behavior of orthodontic archwire alloys coupled to bracket alloys.

PubMed

Iijima, Masahiro; Endo, Kazuhiko; Yuasa, Toshihiro; Ohno, Hiroki; Hayashi, Kazuo; Kakizaki, Mitsugi; Mizoguchi, Itaru

2006-07-01

The purpose of this study was to provide a quantitative assessment of galvanic corrosion behavior of orthodontic archwire alloys coupled to orthodontic bracket alloys in 0.9% NaCl solution and to study the effect of surface area ratios. Two common bracket alloys, stainless steels and titanium, and four common wire alloys, nickel-titanium (NiTi) alloy, beta-titanium (beta-Ti) alloy, stainless steel, and cobalt-chromium-nickel alloy, were used. Three different area ratios, 1:1, 1:2.35, and 1:3.64, were used; two of them assumed that the multibracket appliances consists of 14 brackets and 0.016 inch of round archwire or 0.016 x 0.022 inch of rectangular archwire. The galvanic current was measured for 3 successive days using zero-impedance ammeter. When the NiTi alloy was coupled with Ti (1:1, 1:2.35, and 1:3.64 of the surface area ratio) or beta-Ti alloy was coupled with Ti (1:2.35 and 1:3.64 of the surface area ratio), Ti initially was the anode and corroded. However, the polarity reversed in 1 hour, resulting in corrosion of the NiTi or beta-Ti. The NiTi alloy coupled with SUS 304 or Ti exhibited a relatively large galvanic current density even after 72 hours. It is suggested that coupling SUS 304-NiTi and Ti-NiTi may remarkably accelerate the corrosion of NiTi alloy, which serves as the anode. The different anode-cathode area ratios used in this study had little effect on galvanic corrosion behavior.

Aerosol characterization and pulmonary responses in rats after short-term inhalation of fumes generated during resistance spot welding of galvanized steel.

PubMed

Antonini, James M; Afshari, Aliakbar; Meighan, Terence G; McKinney, Walter; Jackson, Mark; Schwegler-Berry, Diane; Burns, Dru A; LeBouf, Ryan F; Chen, Bean T; Shoeb, Mohammad; Zeidler-Erdely, Patti C

2017-01-01

Resistance spot welding is a common process to join metals in the automotive industry. Adhesives are often used as sealers to seams of metals that are joined. Anti-spatter compounds sometimes are sprayed onto metals to be welded to improve the weldability. Spot welding produces complex aerosols composed of metal and volatile compounds (VOCs) which can cause lung disease in workers. Male Sprague-Dawley rats (n = 12/treatment group) were exposed by inhalation to 25 mg/m 3 of aerosol for 4 h/day × 8 days during spot welding of galvanized zinc (Zn)-coated steel in the presence or absence of a glue or anti-spatter spray. Controls were exposed to filtered air. Particle size distribution and chemical composition of the generated aerosol were determined. At 1 and 7 days after exposure, bronchoalveolar lavage (BAL) was performed to assess lung toxicity. The generated particles mostly were in the submicron size range with a significant number of nanometer-sized particles formed. The primary metals present in the fumes were Fe (72.5%) and Zn (26.3%). The addition of the anti-spatter spray and glue did affect particle size distribution when spot welding galvanized steel, whereas they had no effect on metal composition. Multiple VOCs (e.g., methyl methacrylate, acetaldehyde, ethanol, acetone, benzene, xylene) were identified when spot welding using either the glue or the anti-spatter spray that were not present when welding alone. Markers of lung injury (BAL lactate dehydrogenase) and inflammation (total BAL cells/neutrophils and cytokines/chemokines) were significantly elevated compared to controls 1 day after exposure to the spot welding fumes. The elevated pulmonary response was transient as lung toxicity mostly returned to control values by 7 days. The VOCs or the concentrations that they were generated during the animal exposures had no measurable effect on the pulmonary responses. Inhalation of galvanized spot welding fumes caused acute lung toxicity most

Influence of Aluminum on the Formation Behavior of Zn-Al-Fe Intermetallic Particles in a Zinc Bath

NASA Astrophysics Data System (ADS)

Park, Joo Hyun; Park, Geun-Ho; Paik, Doo-Jin; Huh, Yoon; Hong, Moon-Hi

2012-01-01

The shape, size, and composition of dross particles as a function of aluminum content at a fixed temperature were investigated for aluminum added to the premelted Zn-Fe melt simulating the hot-dip galvanizing bath by a sampling methodology. In the early stage, less than 30 minutes after Al addition, local supersaturation and depletion of the aluminum concentration occurred simultaneously in the bath, resulting in the nucleation and growth of both Fe2Al5Zn x and FeZn13. However, the aluminum was homogenized continuously as the reaction proceeded, and fine and stable FeZn10Al x formed after 30 minutes. An Al-depleted zone (ADZ) mechanism was newly proposed for the "η→η+ζ→δ" phase transformations. The ζ phase bottom dross partly survived for a relatively long period, i.e., 2 hours in this work, whereas the η phase disappeared after 30 minutes. In the early stage of dross formation, both Al-free large particles as well as high-Al tiny particles were formed. The dross particle size decreased slightly with increased reaction time before reaching a plateau. The opposite tendency was observed when the Al content was 0.130 mass pct; with a relatively high Al content, the nucleation of tiny η phase dross was significantly enhanced because of the high degree of supersaturation. This unstable η phase dissolved continuously and underwent simple transformation to the stable δ phase. The relationship between nucleation potential and supersaturation ratio of species is discussed based on the thermodynamics of classical nucleation theory.

Voltage dips at the terminals of wind power installations

NASA Astrophysics Data System (ADS)

Bollen, Math H. J.; Olguin, Gabriel; Martins, Marcia

2005-07-01

This article gives an overview of the kind of voltage dips that can be expected at the terminals of a wind power installation. The overview is based on the study of those dips at the terminals of industrial installations and provides a guideline for the testing of wind power installations against voltage dips. For voltage dips due to faults, a classification into different types is presented. Five types appear at the terminals of sensitive equipment and thus have to be included when testing the wind power installation against disturbances coming from the grid. A distinction is made between installations connected at transmission level and those connected at distribution level. For the latter the phase angle jump has to be considered. Dips due to other causes (motor, transformer and capacitor switching) are briefly discussed as well as the voltage recovery after a dip. Finally some thoughts are presented on the way in which voltage tolerance requirements should be part of the design process for wind power installations. Copyright

Galvanic Corrosion In (Graphite/Epoxy)/Alloy Couples

NASA Technical Reports Server (NTRS)

Danford, Merlin D.; Higgins, Ralph H.

1988-01-01

Effects of galvanic coupling between graphite/epoxy composite material, G/E, and D6AC steel, 6061-T6 aluminum, and Inconel(R) 718 nickel alloy in salt water described in report. Introductory section summarizes previous corrosion studies of G/E with other alloys. Details of sample preparation presented along with photographs of samples before and after immersion.

Galvanic interactions of HE15 /MDN138 & HE15 /MDN250 alloys in natural seawater

NASA Astrophysics Data System (ADS)

Parthiban, G. T.; Subramanian, G.; Muthuraman, K.; Ramakrishna Rao, P.

2017-06-01

HE15 is a heat treatable high strength alloy with excellent machinability find wide applications in aerospace and defence industries. In view of their excellent mechanical properties, workability, machinability, heat treatment characteristics and good resistance to general and stress corrosion cracking, MDN138 & MDN250 have been widely used in petrochemical, nuclear and aerospace industries. The galvanic corrosion behaviour of the metal combinations HE15 /MDN138 and HE15 /MDN250, 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 MDN138, MDN250 and HE15 of the individual metal, the galvanic potential and galvanic current of the couples HE15 /MDN138 and HE15 /MDN250 were periodically monitored throughout the study period. The calcareous deposits on MDN138 and MDN250 in galvanic contact with HE15 were analyzed using XRD. The electrochemical behaviors of MDN138, MDN250 and HE15 in seawater have been studied using an electrochemical work station. The surface characteristics of MDN138 and MDN250 in galvanic contact with HE15 have been examined with scanning electron microscope. The results of the study reveal that HE15 offered required amount of protection to MDN138 & MDN250.

76 FR 23564 - Galvanized Steel Wire From the People's Republic of China: Initiation of Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-27

... the People's Republic of China: Initiation of Countervailing Duty Investigation AGENCY: Import... a countervailing duty (CVD) petition concerning imports of galvanized steel wire from the People's... Duties on Galvanized Steel Wire from the People's Republic of China'' (CVD Petition). On April 6, 2011...

South approach, looking north. The galvanized piping extends from the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South approach, looking north. The galvanized piping extends from the abutments across the length of the arch. - Weaverland Bridge, Quarry Road spanning Conestoga Creek, Terre Hill, Lancaster County, PA

E-Cigs, Menthol & Dip

MedlinePlus

... Close Search × MENU BACK CLOSE SMOKEFREE.GOV HOME E-Cigs, Menthol & Dip There are many types of tobacco products. Learn how e-cigarettes, menthol cigarettes, smokeless tobacco, and other products ...

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

PubMed

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.

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

Optimization of laser welding thin-gage galvanized steel via response surface methodology

NASA Astrophysics Data System (ADS)

Zhao, Yangyang; Zhang, Yansong; Hu, Wei; Lai, Xinmin

2012-09-01

The increasing demand of light weight and durability makes thin-gage galvanized steels (<0.6 mm) attractive for future automotive applications. Laser welding, well known for its deep penetration, high speed and small heat affected zone, provides a potential solution for welding thin-gage galvanized steels in automotive industry. In this study, the effect of the laser welding parameters (i.e. laser power, welding speed, gap and focal position) on the weld bead geometry (i.e. weld depth, weld width and surface concave) of 0.4 mm-thick galvanized SAE1004 steel in a lap joint configuration has been investigated by experiments. The process windows of the concerned process parameters were therefore determined. Then, response surface methodology (RSM) was used to develop models to predict the relationship between the processing parameters and the laser weld bead profile and identify the correct and optimal combination of the laser welding input variables to obtain superior weld joint. Under the optimal welding parameters, defect-free weld were produced, and the average aspect ratio increased about 30%, from 0.62 to 0.83.

Structural Controls of Neal Hot Springs Geothermal Field, Malhuer County, Oregon

NASA Astrophysics Data System (ADS)

Edwards, J. H.; Faulds, J. E.

2012-12-01

Detailed mapping (1:24,000) of the Neal Hot Springs area (90 km2) in eastern Oregon is part of a larger study of geothermal systems in the Basin and Range, which focuses on the structural controls of geothermal activity. The study area lies within the intersection of two regional grabens, the middle-late Miocene, N-striking, Oregon-Idaho graben and younger late Miocene to Holocene, NW-striking, western Snake River Plain graben. The geothermal field is marked by Neal Hot Springs, which effuse from opaline sinter mounds just north of Bully Creek. Wells producing geothermal fluids, with temperatures at 138°C, intersect a major, W-dipping, NNW-striking, high-angle normal fault at depths of 850-915 m. Displacement along this structure dies southward, with likely horse-tailing, which commonly produces high fracture density and a zone of high permeability conducive for channeling hydrothermal fluids. Mapping reveals that the geothermal resource lies within a local, left step-over. 'Hard-linkage' between strands of the left-stepping normal fault, revealed through a study of well chips and well logs, occurs through two concealed structures. Both are W-striking faults, with one that runs parallel to Cottonwood Creek and one 0.5 km N of the creek. Injection wells intersect these two transverse structures within the step-over. Stepping and displacement continue to the NW of the known geothermal field, along W-dipping, N-striking faults that cut lower to middle Miocene Hog Creek Formation, consisting of silicic and mafic volcanic rocks. These N-striking faults were likely initiated during initial Oregon-Idaho graben subsidence (15.3-15.1 Ma), with continued development through late Miocene. Bully Creek Formation deposits, middle to upper Miocene lacustrine and pyroclastic rocks, concomitantly filled the sub half-grabens, and they dip gently to moderately eastward. Younger, western Snake River Plain deposits, upper Miocene to Pliocene fluvial, lacustrine, and pyroclastic rocks

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

PubMed Central

Schaller, Jörg; Weiske, Arndt; Berger, Frank

2013-01-01

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. PMID:24184989

Galvanic Cells and the Determination of Equilibrium Constants

ERIC Educational Resources Information Center

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…

Comparison of piracetam measured with HPLC-DAD, HPLC-ESI-MS, DIP-APCI-MS, and a newly developed and optimized DIP-ESI-MS.

PubMed

Lenzen, Claudia; Winterfeld, Gottfried A; Schmitz, Oliver J

2016-06-01

The direct inlet probe-electrospray ionization (DIP-ESI) presented here was based on the direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI) developed by our group. It was coupled to an ion trap mass spectrometer (MS) for the detection of more polar compounds such as degradation products from pharmaceuticals. First, the position of the ESI tip, the gas and solvent flow rates, as well as the gas temperature were optimized with the help of the statistic program Minitab® 17 and a caffeine standard. The ability to perform quantitative analyses was also tested by using different concentrations of caffeine and camphor. Calibration curves with a quadratic calibration regression of R (2) = 0.9997 and 0.9998 for caffeine and camphor, respectively, were obtained. The limit of detection of 2.5 and 1.7 ng per injection for caffeine and camphor were determined, respectively. Furthermore, a solution of piracetam was used to compare established analytical methods for this drug and its impurities such as HPLC-diode array detector (DAD) and HPLC-ESI-MS with the DIP-APCI and the developed DIP-ESI. With HPLC-DAD and 10 μg piracetam on column, no impurity could be detected. With HPLC-ESI-MS, two impurities (A and B) were identified with only 4.6 μg piracetam on column, while with DIP-ESI, an amount of 1.6 μg piracetam was sufficient. In the case of the DIP-ESI measurements, all detected impurities could be identified by MS/MS studies. Graphical Abstract Scheme of the DIP-ESI principle.

Effect of nano-zinc oxide on nitrogenase activity in legumes: an interplay of concentration and exposure time

NASA Astrophysics Data System (ADS)

Kumar, Praveen; Burman, Uday; Santra, P.

2015-07-01

Experiments were carried out to study the effect of zinc oxide nanoparticles (nano-ZnO) on nitrogenase activity in legumes. In the first experiment, nodulated roots of cluster bean, moth bean, green gram and cowpea were dipped in Hoagland solution containing 1.5 and 10 μg mL-1 of nano-ZnO for 24 h. Nitrogenase activity in cluster bean, green gram and cowpea roots increased after dipping in solution containing 1.5 μg mL-1 nano-ZnO, but decreased in roots dipped in solution containing 10 μg mL-1 nano-ZnO. However, in moth bean roots, nitrogenase activity decreased after dipping in solution containing either concentration of nano-ZnO. In the second experiment, nodulated roots of green gram were dipped in Hoagland solution containing 1, 4, 6, 8 and 10 μg mL-1 nano-ZnO for 6-30 h before estimating nitrogenase activity. Results showed that an interactive effect of nano-ZnO concentration and exposure time influenced nitrogenase activity. The possible reasons behind this effect have been discussed. A model [ A = 3.44 + 0.46 t - 0.01 t 2 - 0.002 tc 2 ( R 2 = 0.81)] involving linear and power components was developed to simulate the response of nitrogenase activity in green gram roots to the concentration and exposure time of nano-ZnO.

Highly Attrition Resistant Zinc Oxide-Based Sorbents for H2S Removal by Spray Drying Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryu, C.K.; Lee, J.B.; Ahn, D.H.

2002-09-19

Primary issues for the fluidized-bed/transport reactor process are high attrition resistant sorbent, its high sorption capacity and regenerability, durability, and cost. The overall objective of this project is the development of a superior attrition resistant zinc oxide-based sorbent for hot gas cleanup in integrated coal gasification combined cycle (IGCC). Sorbents applicable to a fluidized-bed hot gas desulfurization process must have a high attrition resistance to withstand the fast solid circulation between a desulfurizer and a regenerator, fast kinetic reactions, and high sulfur sorption capacity. The oxidative regeneration of zinc-based sorbent usually initiated at greater than 600 C with highly exothermicmore » nature causing deactivation of sorbent as well as complication of sulfidation process by side reaction. Focusing on solving the sorbent attrition and regenerability of zinc oxide-based sorbent, we have adapted multi-binder matrices and direct incorporation of regeneration promoter. The sorbent forming was done with a spray drying technique that is easily scalable to commercial quantity.« less

76 FR 68407 - Galvanized Steel Wire From the People's Republic of China: Preliminary Determination of Sales at...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-04

..., shorter strands of galvanized wire are purely for non-industrial, personal use, this galvanized [[Page... Co.; Nantong Long Yang International Trade Co., Ltd.; Shaanxi New Mile International Trade Co. Ltd... per capita gross national income are comparable to the PRC in terms of economic development.\\20\\ On...

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

NASA Astrophysics Data System (ADS)

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

Social support and nocturnal blood pressure dipping: a systematic review.

PubMed

Fortmann, Addie L; Gallo, Linda C

2013-03-01

Attenuated nocturnal blood pressure (BP) dipping is a better predictor of cardiovascular disease (CVD) morbidity and mortality than resting BP measurements. Studies have reported associations between social support, variously defined, and BP dipping. A systematic review of the literature was conducted to investigate associations of functional and structural social support with nocturnal BP dipping assessed over a minimum of 24 hours. A total of 297 articles were identified. Of these, 11 met criteria for inclusion; all studies were cross-sectional in design and included adult participants only (mean age = 19 to 72 years). Evidence was most consistent for an association between functional support and BP dipping, such that 5 of 7 studies reported statistically (or marginally) significant positive associations with BP dipping. Statistically significant functional support-BP dipping associations were moderate (standardized effect size (d) = 0.41) to large (d = 2.01) in magnitude. Studies examining structural support were fewer and relatively less consistent; however, preliminary evidence was observed for associations of marital status and social contact frequency with BP dipping. Statistically significant structural support findings were medium (d = 0.53) to large (d = 1.13) in magnitude. Overall, findings suggest a link between higher levels of functional support and greater nocturnal BP dipping; preliminary evidence was also observed for the protective effects of marriage and social contact frequency. Nonetheless, the relatively small number of studies conducted to date and the heterogeneity of findings across meaningful subgroups suggest that additional research is needed to substantiate these conclusions.

Eigenvector of gravity gradient tensor for estimating fault dips considering fault type

NASA Astrophysics Data System (ADS)

Kusumoto, Shigekazu

2017-12-01

The dips of boundaries in faults and caldera walls play an important role in understanding their formation mechanisms. The fault dip is a particularly important parameter in numerical simulations for hazard map creation as the fault dip affects estimations of the area of disaster occurrence. In this study, I introduce a technique for estimating the fault dip using the eigenvector of the observed or calculated gravity gradient tensor on a profile and investigating its properties through numerical simulations. From numerical simulations, it was found that the maximum eigenvector of the tensor points to the high-density causative body, and the dip of the maximum eigenvector closely follows the dip of the normal fault. It was also found that the minimum eigenvector of the tensor points to the low-density causative body and that the dip of the minimum eigenvector closely follows the dip of the reverse fault. It was shown that the eigenvector of the gravity gradient tensor for estimating fault dips is determined by fault type. As an application of this technique, I estimated the dip of the Kurehayama Fault located in Toyama, Japan, and obtained a result that corresponded to conventional fault dip estimations by geology and geomorphology. Because the gravity gradient tensor is required for this analysis, I present a technique that estimates the gravity gradient tensor from the gravity anomaly on a profile.

21 CFR 882.1540 - Galvanic skin response measurement device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Galvanic skin response measurement device. 882.1540 Section 882.1540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1540...

Pseudarthrosis due to galvanic corrosion presenting as subarachnoid hemorrhage.

PubMed

Beavers, Rosemary Noel; Lall, Rishi Rajiv; Barnett, Juan Ortega; Desai, Sohum Kiran

2017-01-01

Two unlike metals near one another can break down as they move toward electrochemical equilibrium resulting in galvanic corrosion. We describe a case of electrochemical corrosion resulting in pseudarthrosis, followed by instrumentation failure leading to subarachnoid hemorrhage. A 53-year-old female with a history of cervical instability and two separate prior cervical fusion surgery with sublaminar cables presented with new onset severe neck pain. Restricted range of motion in her neck and bilateral Hoffman's was noted. X-ray of her cervical spine was negative. A noncontrast CT scan of her head and neck showed subarachnoid hemorrhage in the prepontine and cervicomedullary cisterns. Neurosurgical intervention involved removal of prior stainless steel and titanium cables, repair of cerebrospinal fluid leak, and nonsegmental C1-C3 instrumented fusion. She tolerated the surgery well and followed up without complication. Galvanic corrosion of the Brook's fusion secondary to current flow between dissimilar metal alloys resulted in catastrophic instrumentation failure and subarachnoid hemorrhage.

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

NASA Astrophysics Data System (ADS)

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.

Cytotoxic effect of galvanically coupled magnesium-titanium particles.

PubMed

Kim, Jua; Gilbert, Jeremy L

2016-01-01

Recent work has shown that reduction reactions at metallic biomaterial surfaces can induce significant killing of cells in proximity to the surface. To exploit this phenomenon for therapeutic purposes, for example, for cancer tumor killing or antibacterial effects (amongst other applications), magnesium metal particles, galvanically coupled to titanium by sputtering, have been evaluated for their cell-killing capability (i.e. cytotoxicity). Magnesium (Mg) particles large enough to prevent particle phagocytosis were investigated, so that only electrochemical reactions, and not particle toxicity per se, caused cytotoxic effects. Titanium (Ti) coated magnesium particles, as well as magnesium-only particles were introduced into MC3T3-E1 mouse pre-osteoblast cell cultures over a range of particle concentrations, and cells were observed to die in a dosage-dependent manner. Ti-coated magnesium particles killed more cells at lower particle concentration than magnesium alone (P<0.05), although the pH measured for magnesium and magnesium-titanium had no significant difference at similar particle concentrations. Complete cell killing occurred at 750μg/ml and 1500μg/ml for Mg-Ti and Mg, respectively. Thus, this work demonstrates that galvanically coupled Mg-Ti particles have a significant cell killing capability greater than Mg alone. In addition, when the pH associated with complete killing with particles was created using NaOH only (no particles), then the percentage of cells killed was significantly less (P<0.05). Together, these findings show that pH is not the sole factor associated with cell killing and that the electrochemical reactions, including the reduction reactions, play an important role. Reduction reactions on galvanically coupled Mg-Ti and Mg particles may generate reactive oxygen intermediates that are able to kill cells in close proximity to the particles and this approach may lead to potential therapies for infection and cancer. This paper demonstrates

A&M. TAN607. Interior view of operating gallery in hot shop. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. TAN-607. Interior view of operating gallery in hot shop. Shielded viewing windows are along right side of corridor. Cabinet on wheels at left of corridor is operating console for hot shop manipulators. When in use, it is stationed at window station and connected to appropriate control cables. note reserve bottles of zinc bromide above each station. Date: January 3, 1955. INEEL negative no. 55-0072 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Cycle oxidation behavior and anti-oxidation mechanism of hot-dipped aluminum coating on TiBw/Ti6Al4V composites with network microstructure.

PubMed

Li, X T; Huang, L J; Wei, S L; An, Q; Cui, X P; Geng, L

2018-04-10

Controlled and compacted TiAl 3 coating was successfully fabricated on the network structured TiBw/Ti6Al4V composites by hot-dipping aluminum and subsequent interdiffusion treatment. The network structure of the composites was inherited to the TiAl 3 coating, which effectively reduces the thermal stress and avoids the cracks appeared in the coating. Moreover, TiB reinforcements could pin the TiAl 3 coating which can effectively improve the bonding strength between the coating and composite substrate. The cycle oxidation behavior of the network structured coating on 873 K, 973 K and 1073 K for 100 h were investigated. The results showed the coating can remarkably improve the high temperature oxidation resistance of the TiBw/Ti6Al4V composites. The network structure was also inherited to the Al 2 O 3 oxide scale, which effectively decreases the tendency of cracking even spalling about the oxide scale. Certainly, no crack was observed in the coating after long-term oxidation due to the division effect of network structured coating and pinning effect of TiB reinforcements. Interfacial reaction between the coating and the composite substrate occurred and a bilayer structure of TiAl/TiAl 2 formed next to the substrate after oxidation at 973 K and 1073 K. The anti-oxidation mechanism of the network structured coating was also discussed.

Time Resolved X-Ray Spectral Analysis of Class II YSOs in NGC 2264 During Optical Dips and Bursts

NASA Astrophysics Data System (ADS)

Guarcello, Mario Giuseppe; Flaccomio, Ettore; Micela, Giuseppina; Argiroffi, Costanza; Venuti, Laura

2016-07-01

Pre-Main Sequence stars are variable sources. The main mechanisms responsible for their variability are variable extinction, unsteady accretion, and rotational modulation of both hot and dark photospheric spots and X-ray active regions. In stars with disks this variability is thus related to the morphology of the inner circumstellar region (<0.1 AU) and that of photosphere and corona, all impossible to be spatially resolved with present day techniques. This has been the main motivations of the Coordinated Synoptic Investigation of NGC2264, a set of simultaneous observations of NGC2264 with 15 different telescopes.We analyze the X-ray spectral properties of stars with disks extracted during optical bursts and dips in order to unveil the nature of these phenomena. Stars are analyzed in two different samples. In stars with variable extinction a simultaneous increase of optical extinction and X-ray absorption is searched during the optical dips; in stars with accretion bursts we search for soft X-ray emission and increasing X-ray absorption during the bursts. In 9/33 stars with variable extinction we observe simultaneous increase of X-ray absorption and optical extinction. In seven dips it is possible to calculate the NH/AV ratio in order to infer the composition of the obscuring material. In 5/27 stars with optical accretion bursts, we observe soft X-ray emission during the bursts that we associate to the emission of accreting gas. It is not surprising that these properties are not observed in all the stars with dips and bursts since favorable geometric configurations are required. The observed variable absorption during the dips is mainly due to dust-free material in accretion streams. In stars with accretion bursts we observe in average a larger soft X-ray spectral component not observed in non accreting stars. This indicates that this soft X-ray emission arises from the accretion shocks.

Microstructure and Mechanical Properties of Plasma Arc Brazed AISI 304L Stainless Steel and Galvanized Steel Plates

NASA Astrophysics Data System (ADS)

Jin, Yajuan; Li, Ruifeng; Yu, Zhishui; Wang, Yu

2016-04-01

Plasma arc brazing is used to join the AISI 304L stainless steel and galvanized steel plate butt joints with the CuSi3Mn1 filler wire. The effect of parameters on weld surface appearance, interfacial microstructure, and composition distribution in the joint was studied. The microhardness and mechanical tests were conducted to determine the mechanical properties of the welded specimens. The results indicated that good appearance, bead shape, and sufficient metallurgical bonding could be obtained when the brazing process was performed with a wire feeding speed of 0.8 m/min, plasma gas flow rate of 3.0 l/min, welding current of 100 A, and welding speed of 27 cm/min. During plasma arc brazing process, the top corner of the stainless steel and galvanized steel plate were heated and melted, and the melted quantity of stainless steel was much more than that of the galvanized steel due to the thermal conductivity coefficient difference between the dissimilar materials. The microhardness test results shows that the microhardness value gradually increased from the side of the galvanized steel to the stainless steel in the joint, and it is good for improving the mechanical properties of joint. The tensile strength was a little higher than that of the brazing filler, and the fracture position of weld joint was at the base metal of galvanized steel plate.

The First Post-Kepler Brightness Dips of KIC 8462852

NASA Astrophysics Data System (ADS)

Boyajian, Tabetha. S.; Alonso, Roi; Ammerman, Alex; Armstrong, David; Asensio Ramos, A.; Barkaoui, K.; Beatty, Thomas G.; Benkhaldoun, Z.; Benni, Paul; Bentley, Rory O.; Berdyugin, Andrei; Berdyugina, Svetlana; Bergeron, Serge; Bieryla, Allyson; Blain, Michaela G.; Capetillo Blanco, Alicia; Bodman, Eva H. L.; Boucher, Anne; Bradley, Mark; Brincat, Stephen M.; Brink, Thomas G.; Briol, John; Brown, David J. A.; Budaj, J.; Burdanov, A.; Cale, B.; Aznar Carbo, Miguel; Castillo García, R.; Clark, Wendy J.; Clayton, Geoffrey C.; Clem, James L.; Coker, Phillip H.; Cook, Evan M.; Copperwheat, Chris M.; Curtis, J. L.; Cutri, R. M.; Cseh, B.; Cynamon, C. H.; Daniels, Alex J.; Davenport, James R. A.; Deeg, Hans J.; De Lorenzo, Roberto; de Jaeger, Thomas; Desrosiers, Jean-Bruno; Dolan, John; Dowhos, D. J.; Dubois, Franky; Durkee, R.; Dvorak, Shawn; Easley, Lynn; Edwards, N.; Ellis, Tyler G.; Erdelyi, Emery; Ertel, Steve; Farfán, Rafael. G.; Farihi, J.; Filippenko, Alexei V.; Foxell, Emma; Gandolfi, Davide; Garcia, Faustino; Giddens, F.; Gillon, M.; González-Carballo, Juan-Luis; González-Fernández, C.; González Hernández, J. I.; Graham, Keith A.; Greene, Kenton A.; Gregorio, J.; Hallakoun, Na’ama; Hanyecz, Ottó; Harp, G. R.; Henry, Gregory W.; Herrero, E.; Hildbold, Caleb F.; Hinzel, D.; Holgado, G.; Ignácz, Bernadett; Ilyin, Ilya; Ivanov, Valentin D.; Jehin, E.; Jermak, Helen E.; Johnston, Steve; Kafka, S.; Kalup, Csilla; Kardasis, Emmanuel; Kaspi, Shai; Kennedy, Grant M.; Kiefer, F.; Kielty, C. L.; Kessler, Dennis; Kiiskinen, H.; Killestein, T. L.; King, Ronald A.; Kollar, V.; Korhonen, H.; Kotnik, C.; Könyves-Tóth, Réka; Kriskovics, Levente; Krumm, Nathan; Krushinsky, Vadim; Kundra, E.; Lachapelle, Francois-Rene; LaCourse, D.; Lake, P.; Lam, Kristine; Lamb, Gavin P.; Lane, Dave; Lau, Marie Wingyee; Lewin, Pablo; Lintott, Chris; Lisse, Carey; Logie, Ludwig; Longeard, Nicolas; Lopez Villanueva, M.; Whit Ludington, E.; Mainzer, A.; Malo, Lison; Maloney, Chris; Mann, A.; Mantero, A.; Marengo, Massimo; Marchant, Jon; Martínez González, M. J.; Masiero, Joseph R.; Mauerhan, Jon C.; McCormac, James; McNeely, Aaron; Meng, Huan Y. A.; Miller, Mike; Molnar, Lawrence A.; Morales, J. C.; Morris, Brett M.; Muterspaugh, Matthew W.; Nespral, David; Nugent, C. R.; Nugent, Katherine M.; Odasso, A.; O’Keeffe, Derek; Oksanen, A.; O’Meara, John M.; Ordasi, András; Osborn, Hugh; Ott, John J.; Parks, J. R.; Rodriguez Perez, Diego; Petriew, Vance; Pickard, R.; Pál, András; Plavchan, P.; Pollacco, Don; Pozo Nuñez, F.; Pozuelos, F. J.; Rau, Steve; Redfield, Seth; Relles, Howard; Ribas, Ignasi; Richards, Jon; Saario, Joonas L. O.; Safron, Emily J.; Sallai, J. Martin; Sárneczky, Krisztián; Schaefer, Bradley E.; Schumer, Clea F.; Schwartzendruber, Madison; Siegel, Michael H.; Siemion, Andrew P. V.; Simmons, Brooke D.; Simon, Joshua D.; Simón-Díaz, S.; Sitko, Michael L.; Socas-Navarro, Hector; Sódor, Á.; Starkey, Donn; Steele, Iain A.; Stone, Geoff; Strassmeier, Klaus G.; Street, R. A.; Sullivan, Tricia; Suomela, J.; Swift, J. J.; Szabó, Gyula M.; Szabó, Róbert; Szakáts, Róbert; Szalai, Tamás; Tanner, Angelle M.; Toledo-Padrón, B.; Tordai, Tamás; Triaud, Amaury H. M. J.; Turner, Jake D.; Ulowetz, Joseph H.; Urbanik, Marian; Vanaverbeke, Siegfried; Vanderburg, Andrew; Vida, Krisztián; Vietje, Brad P.; Vinkó, József; von Braun, K.; Waagen, Elizabeth O.; Walsh, Dan; Watson, Christopher A.; Weir, R. C.; Wenzel, Klaus; Westendorp Plaza, C.; Williamson, Michael W.; Wright, Jason T.; Wyatt, M. C.; Zheng, WeiKang; Zsidi, Gabriella

2018-01-01

We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%–2.5% dips, named “Elsie,” “Celeste,” “Skara Brae,” and “Angkor,” which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale ≪1 μm, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term “secular” dimming, which may be caused by independent processes, or probe different regimes of a single process.

Experimental galvanic anode for cathodic protection of Bridge A12112

DOT National Transportation Integrated Search

2010-11-01

Cathodic Protection (CP) has been used by MoDOT for more than 30 years to stop : corrosion of reinforced concrete bridge decks. These systems require power from local electrical : connections. A galvanic system uses the difference in electrical poten...

29 CFR 1910.124 - General requirements for dipping and coating operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... or exceeds 25% of its LFL. (2) You must ensure that any exhaust air re-circulated from a dipping or... employee enters a dip tank? When an employee enters a dip tank, you must meet the entry requirements of...

An Easy-to-Assemble Three-Part Galvanic Cell

ERIC Educational Resources Information Center

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…

76 FR 21914 - Galvanized Steel Wire From China and Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-19

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-479 and 731-TA-1183-1184 (Preliminary)] Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject antidumping and countervailing duty investigations. DATES: Effective Date...

A Novel Field-Circuit FEM Modeling and Channel Gain Estimation for Galvanic Coupling Real IBC Measurements.

PubMed

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.

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

PubMed

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.

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

PubMed Central

Gelfi, Marcello; Solazzi, Luigi; Poli, Sandro

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. 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. PMID:28772623

Effects of heat input on mechanical properties of metal inert gas welded 1.6 mm thick galvanized steel sheet

NASA Astrophysics Data System (ADS)

Rafiqul, M. I.; Ishak, M.; Rahman, M. M.

2012-09-01

It is usually a lot easier and less expensive to galvanize steel before it is welded into useful products. Galvanizing afterwards is almost impossible. In this research work, Galvanized Steel was welded by using the ER 308L stainless steel filler material. This work was done to find out an alternative way of welding and investigate the effects of heat input on the mechanical properties of butt welded joints of Galvanized Steel. A 13.7 kW maximum capacity MIG welding machine was used to join 1.6 mm thick sheet of galvanized steel with V groove and no gap between mm. Heat inputs was gradually increased from 21.06 to 25.07 joules/mm in this study. The result shows almost macro defects free welding and with increasing heat input the ultimate tensile strength and welding efficiency decrease. The Vickers hardness also decreases at HAZ with increasing heat input and for each individual specimen; hardness was lowest in heat affected zone (HAZ), intermediate in base metal and maximum in welded zone. The fracture for all specimens was in the heat affected zone while testing in the universal testing machine.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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 <100 nm (originating from impurities of the electrolyte solution) and Pd and Ag cluster ions for films with a 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.

Diamondlike carbon coating as a galvanic corrosion barrier between dental implant abutments and nickel-chromium superstructures.

PubMed

Ozkomur, Ahmet; Erbil, Mehmet; Akova, Tolga

2013-01-01

The objectives of this study were to evaluate the galvanic corrosion behavior between titanium and nickel-chromium (Ni-Cr) alloy, to investigate the effect of diamondlike carbon (DLC) coating over titanium on galvanic corrosion behavior between titanium and Ni-Cr alloy, and to evaluate the effect of DLC coating over titanium abutments on the fit and integrity of prosthetic assemblies by scanning electron microcopy (SEM). Five Ni-Cr and 10 titanium disks with a diameter of 5 mm and thickness of 3 mm were prepared. DLC coating was applied to five titanium disks. Electrode samples were prepared, and open circuit potential measurements, galvanic current measurements over platinum electrodes, and potentiodynamic polarization tests were carried out. For the SEM evaluation, 20 Ni-Cr alloy and 10 gold alloy superstructures were cast and prepared over 30 abutments. DLC coating was applied to 10 of the abutments. Following the fixation of prosthetic assemblies, the samples were embedded in acrylic resin and cross sectioned longitudinally. Internal fit evaluations were carried out through examination of the SEM images. Titanium showed more noble and electrochemically stable properties than Ni-Cr alloy. DLC coating over the cathode electrode served as an insulating film layer over the surface and prevented galvanic coupling. Results of the SEM evaluations indicated that the DLC-coated and titanium abutments showed no statistically significant difference in fit. Hence, no adverse effects on the adaptation of prosthetic components were found with the application of DLC coating over abutment surfaces. DLC coating might serve as a galvanic corrosion barrier between titanium abutments and Ni-Cr superstructures.

A case study of an erosion control practice: the broad-based dip

Treesearch

Kevin Bold; Pamela Edwards; Karl Williard

2007-01-01

In 2006, 19 gravel haul roads with broad-based dips within the Monongahela National Forest were examined to determine if those dips adhered to Forest specifications for cut depth and dip outslope. Data on the azimuth, contributing road lengths, slopes of the contributing lengths, landscape position of the dip, and soil texture of the road bed materials also were...

Constraints on the long-period moment-dip tradeoff for the Tohoku earthquake

USGS Publications Warehouse

Tsai, Victor C.; Hayes, Gavin P.; Duputel, Zacharie

2011-01-01

Since the work of Kanamori and Given (1981), it has been recognized that shallow, pure dip-slip earthquakes excite long-period surface waves such that it is difficult to independently constrain the moment (M0) and the dip (δ) of the source mechanism, with only the product M0 sin(2δ) being well constrained. Because of this, it is often assumed that the primary discrepancies between the moments of shallow, thrust earthquakes are due to this moment-dip tradeoff. In this work, we quantify how severe this moment-dip tradeoff is depending on the depth of the earthquake, the station distribution, the closeness of the mechanism to pure dip-slip, and the quality of the data. We find that both long-period Rayleigh and Love wave modes have moment-dip resolving power even for shallow events, especially when stations are close to certain azimuths with respect to mechanism strike and when source depth is well determined. We apply these results to USGS W phase inversions of the recent M9.0 Tohoku, Japan earthquake and estimate the likely uncertainties in dip and moment associated with the moment- dip tradeoff. After discussing some of the important sources of moment and dip error, we suggest two methods for potentially improving this uncertainty.

77 FR 17430 - Galvanized Steel Wire From the People's Republic of China: Final Determination of Sales at Less...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-975] Galvanized Steel Wire From... wire from the People's Republic of China (``PRC'').\\1\\ On November 29, 2011, the Department published... galvanized steel wire from the PRC is being, or is likely to be, sold in the United States at LTFV, as...

Constraints on the long-period moment-dip tradeoff for the Tohoku earthquake

USGS Publications Warehouse

Tsai, V.C.; Hayes, G.P.; Duputel, Z.

2011-01-01

Since the work of Kanamori and Given (1981), it has been recognized that shallow, pure dip-slip earthquakes excite long-period surface waves such that it is difficult to independently constrain the moment (M0) and the dip (??) of the source mechanism, with only the product M0 sin(2??) being well constrained. Because of this, it is often assumed that the primary discrepancies between the moments of shallow, thrust earthquakes are due to this moment-dip tradeoff. In this work, we quantify how severe this moment-dip tradeoff is depending on the depth of the earthquake, the station distribution, the closeness of the mechanism to pure dip-slip, and the quality of the data. We find that both long-period Rayleigh and Love wave modes have moment-dip resolving power even for shallow events, especially when stations are close to certain azimuths with respect to mechanism strike and when source depth is well determined. We apply these results to USGS W phase inversions of the recent M9.0 Tohoku, Japan earthquake and estimate the likely uncertainties in dip and moment associated with the moment-dip tradeoff. After discussing some of the important sources of moment and dip error, we suggest two methods for potentially improving this uncertainty. Copyright 2011 by the American Geophysical Union.

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

NASA Astrophysics Data System (ADS)

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°.

Peak-dip-hump lineshape from holographic superconductivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, J.-W.; Kao, Y.-J.; Wen, W.-Y.

2010-07-15

We study the fermionic spectral function in a holographic superconductor model. At zero temperature, there is no horizon and hence the entropy of the system is zero after the backreaction of the condensate is taken into account. We find the system exhibits the famous peak-dip-hump lineshape with a sharp low-energy peak followed by a dip and then a hump at higher energies. This feature is widely observed in the spectrum of several high-T{sub c} superconductors.

Structural Characterization and Antifungal Studies of Zinc-Doped Hydroxyapatite Coatings.

PubMed

Iconaru, Simona Liliana; Prodan, Alina Mihaela; Buton, Nicolas; Predoi, Daniela

2017-04-09

The present study is focused on the synthesis, characterization and antifungal evaluation of zinc-doped hydroxyapatite (Zn:HAp) coatings. The Zn:HAp coatings were deposited on a pure Si (Zn:HAp_Si) and Ti (Zn:HAp_Ti) substrate by a sol-gel dip coating method using a zinc-doped hydroxyapatite nanogel. The nature of the crystal phase was determined by X-ray diffraction (XRD). The crystalline phase of the prepared Zn:HAp composite was assigned to hexagonal hydroxyapatite in the P6 3/m space group. The colloidal properties of the resulting Zn:HAp (x Zn = 0.1) nanogel were analyzed by Dynamic Light Scattering (DLS) and zeta potential. Scanning Electron Microscopy (SEM) was used to investigate the morphology of the zinc-doped hydroxyapatite (Zn:HAp) nanogel composite and Zn:HAp coatings. The elements Ca, P, O and Zn were found in the Zn:HAp composite. According to the EDX results, the degree of Zn substitution in the structure of Zn:HAp composite was 1.67 wt%. Moreover, the antifungal activity of Zn:HAp_Si and Zn:HAp_Ti against Candida albicans ( C. albicans ) was evaluated. A decrease in the number of surviving cells was not observed under dark conditions, whereas under daylight and UV light illumination a major decrease in the number of surviving cells was observed.

Dip Spectroscopy of the Low Mass X-Ray Binary XB 1254-690

NASA Technical Reports Server (NTRS)

Smale, Alan P.; Church, M. J.; BalucinskaChurch, M.; White, Nicholas E. (Technical Monitor)

2002-01-01

We observed the low mass X-ray binary XB 1254-690 with the Rossi X-ray Timing Explorer in 2001 May and December. During the first observation strong dipping on the 3.9-hr orbital period and a high degree of variability were observed, along with "shoulders" approx. 15% deep during extended intervals on each side of the main dips. The first observation also included pronounced flaring activity. The non-dip spectrum obtained using the PCA instrument was well-described by a two-component model consisting of a blackbody with kT = 1.30 +/- 0.10 keV plus a cut-off power law representation of Comptonized emission with power law photon index 1.10 +/- 0.46 and a cut-off energy of 5.9(sup +3.0, sub -1.4) keV. The intensity decrease in the shoulders of dipping is energy-independent, consistent with electron scattering in the outer ionized regions of the absorber. In deep dipping the depth of dipping reached 100%, in the energy band below 5 keV, indicating that all emitting regions were covered by absorber. Intensity-selected dip spectra were well-fit by a model in which the point-like blackbody is rapidly covered, while the extended Comptonized emission is progressively overlapped by the absorber, with the, covering fraction rising to 95% in the deepest portion of the dip. The intensity of this component in the dip spectra could be modeled by a combination of electron scattering and photoelectric absorption. Dipping did not occur during the 2001 December observation, but remarkably, both bursting and flaring were observed contemporaneously.

Seismological constraints on the down-dip shape of normal faults

NASA Astrophysics Data System (ADS)

Reynolds, Kirsty; Copley, Alex

2018-04-01

We present a seismological technique for determining the down-dip shape of seismogenic normal faults. Synthetic models of non-planar source geometries reveal the important signals in teleseismic P and SH waveforms that are diagnostic of down-dip curvature. In particular, along-strike SH waveforms are the most sensitive to variations in source geometry, and have significantly more complex and larger-amplitude waveforms for curved source geometries than planar ones. We present the results of our forward-modelling technique for 13 earthquakes. Most continental normal-faulting earthquakes that rupture through the full seismogenic layer are planar and have dips of 30°-60°. There is evidence for faults with a listric shape from some of the earthquakes occurring in two regions; Tibet and East Africa. These ruptures occurred on antithetic faults, or minor faults within the hanging walls of the rifts affected, which may suggest a reason for the down-dip curvature. For these earthquakes, the change in dip across the seismogenic part of the fault plane is ≤30°.

Analysis of Slug Test Response in a Fracture of a Large Dipping Angle

NASA Astrophysics Data System (ADS)

Chen, C.

2013-12-01

A number of cross-borehole slug tests were conducted in a Cenozoic folded sandstone formation, where a fracture has a dipping angle as large as 47°. As all the slug test models available in literature assume the formation to be horizontal, a slug test model taking into account the dipping angle effect is developed herein. Due to the presence of the dipping angle, there is a uniform regional groundwater flow, and the flow field generated by the test is not raidally symmetrical with respect to the test well. When the fracture hydraulic conductivity is relatively low, a larger dipping angle causes larger wellbore flow rates, leading to a faster recovery of the non-oscillatory test response. When the fracture hydraulic conductivity is relatively high, a larger dipping angle causes smaller wellbore heads, resulting in an increase of amplitude of the oscillatory test response; yet little influence on the frequency of oscillation. In general, neglecting the dipping angle may lead to an overestimate of hydraulic conductivity and an underestimate of the storage coefficient. The dipping angle effect is more pronounced for a larger storage coefficient, being less sensitive to transmissivity. An empirical relationship is developed for the minimum dipping angle, smaller than which the dipping angle effect can be safely neglected, as a function of the dimensionless storage coefficient. This empirical relationship helps evaluate whether or not the dipping angle needs to be considered in data analysis. The slug test data in the fracture of a 47°dipping angle is analyzed using the current model, and it is found that neglecting the dip angle can result in a 30% overestimate of transmissivity and a 61% underestimate of the storage coefficient.

Comparison of Galvanic Currents Generated Between Different Combinations of Orthodontic Brackets and Archwires Using Potentiostat: An In Vitro Study.

PubMed

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

UNDERSTANDING THE STRUCTURE OF THE HOT INTERSTELLAR MEDIUM IN NORMAL EARLY-TYPE GALAXIES.

NASA Astrophysics Data System (ADS)

Traynor, Liam; Kim, Dong-Woo; Chandra Galaxy Atlas

2018-01-01

The hot interstellar medium (ISM) of early-type galaxies (ETG's) provides crucial insight into the understanding of their formation and evolution. Mechanisms such as type Ia supernovae heating, AGN feedback, deepening potential depth through dark matter assembly and ramp-pressure stripping are known to affect the structure of the ISM. By using temperature maps and radial temperature profiles of the hot ISM from ~70 ETG's with archival Chandra data, it is possible to classify the galaxy's ISM into common structural types. This is extended by using 3D fitting of the radial temperature profile in order to provide models that further constrain the structural types. Five structural types are present, negative (temperature decreases with radii), positive (temperature increases with radii), hybrid-dip (temperature decreases at small radii and increases at large radii), hybrid-bump (inverse of hybrid-dip) and quasi-isothermal (temperature is constant at all radii). This work will be continued by 1) determining which mechanisms are present in which galaxies and 2) analysing the model parameters between galaxies within each structural type to determine whether each type can be described by a single set of model parameters, indicating that the same physical processes are responsible for creating that structural type.

Evidence for hot clumpy accretion flow in the transitional millisecond pulsar PSR J1023+0038

NASA Astrophysics Data System (ADS)

Shahbaz, T.; Dallilar, Y.; Garner, A.; Eikenberry, S.; Veledina, A.; Gandhi, P.

2018-06-01

We present simultaneous optical and near-infrared (IR) photometry of the millisecond pulsar PSR J1023+0038 during its low-mass X-ray binary phase. The r΄- and Ks-band light curves show rectangular, flat-bottomed dips, similar to the X-ray mode-switching (active-passive state transitions) behaviour observed previously. The cross-correlation function (CCF) of the optical and near-IR data reveals a strong, broad negative anticorrelation at negative lags, a broad positive correlation at positive lags, with a strong, positive narrow correlation superimposed. The shape of the CCF resembles the CCF of black hole X-ray binaries but the time-scales are different. The features can be explained by reprocessing and a hot accretion flow close to the neutron star's magnetospheric radius. The optical emission is dominated by the reprocessed component, whereas the near-IR emission contains the emission from plasmoids in the hot accretion flow and a reprocessed component. The rapid active-passive state transition occurs when the hot accretion flow material is channelled on to the neutron star and is expelled from its magnetosphere. During the transition the optical reprocessing component decreases resulting in the removal of a blue spectral component. The accretion of clumpy material through the magnetic barrier of the neutron star produces the observed near-IR/optical CCF and variability. The dip at negative lags corresponds to the suppression of the near-IR synchrotron component in the hot flow, whereas the broad positive correlation at positive lags is driven by the increased synchrotron emission of the outflowing plasmoids. The narrow peak in the CCF is due to the delayed reprocessed component, enhanced by the increased X-ray emission.

ASCA Observation of the Dipping X-Ray Source X1916-053

NASA Technical Reports Server (NTRS)

Ko, Yuan-Kuen; Makai, Koji; Smale, Alan P.; White, Nick E.

1997-01-01

We present the results of timing and spectral studies of the dipping X-ray source X1916-053, observed by ASCA during its Performance Verification phase. The detected dipping activity is consistent with previous observations, with a period of 3008s and an intermittent secondary dip observed roughly 0.4 out of phase with the primary dip. The energy spectra of different intensity states are fitted with a power law with partial covering fraction absorption and interstellar absorption. The increase in the hardness ratio during the primary and secondary dips, and the increase in the covering fraction and column density with decreasing X-ray intensity, all imply that the dipping is caused by the photo-absorbing materials which have been suggested to be where the accreted flow hits the outer edge of the disk materials. The spectra at all intensity levels show no apparent evidence for Fe or Ne emission lines. This may be due to the low metal abundance in the accretion flow. Alternatively, the X-ray luminosity of the central source may be too weak to excite emission lines, which are assumed to be produced by X-ray photoionization of the disk materials.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans.

PubMed

Mellman, Thomas A; Brown, Tyish S Hall; Kobayashi, Ihori; Abu-Bader, Soleman H; Lavela, Joseph; Altaee, Duaa; McLaughlin, Latesha; Randall, Otelio S

2015-08-01

Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans. We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans. One hundred thirty-six black, predominately African American, men and women with a mean age of 22.9 years (SD = 4.6) filled out surveys and were interviewed and had two, 24-h ambulatory BP recordings. Thirty-eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance. Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research.

Transmission electron microscopy characterization of the interfacial structure of a galvanized dual-phase steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aslam, I., E-mail: ia31@msstate.edu

2016-10-15

Site-specific studies were carried out to characterize the interface of a galvanized dual-phase (DP) steel. Focused ion beam (FIB) was used to prepare specimens in the interface region (~ 100 nm thick) between the coating and the substrate. Transmission electron microscopy (TEM), scanning TEM (STEM), and high resolution TEM (HRTEM) were performed to resolve the phases and the structures at the interface between the zinc (Zn) coating and the steel substrate. The STEM and TEM results showed that a continuous manganese oxide (MnO) film with a thickness of ~ 20 nm was present on the surface of the substrate whilemore » no silicon (Si) oxides were resolved. Internal oxide particles were observed as well in the sub-surface region. Despite the presence of the continuous oxide film, a well-developed inhibition layer was observed right on top of the oxide film. The inhibition layer has a thickness of ~ 100 nm. Possible mechanisms for the growth of the inhibition layer were discussed. - Highlights: •Site-specific examinations were performed on the Zn/steel interface. •Continuous external MnO oxides (20 nm) were observed at the interface. •No Si oxides were observed at the interface. •Internal oxide particles were distributed in the subsurface. •A continuous inhibition layer grew on top of the external oxides.« less

Mineralogy of Galvanic Corrosion By-products in Domestic Drinking Water Pipes

EPA Science Inventory

This study presents the results of a visual and mineralogical characterization of scales developed over long time periods at galvanically coupled lead-brass and lead-copper pipe joints from several different drinking water distribution systems. The long-term exposure aspect of t...

Zinc electrode and rechargeable zinc-air battery

DOEpatents

Ross, Jr., Philip N.

1989-01-01

An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

Treatment of industrial wastewater containing Congo Red and Naphthol Green B using low-cost adsorbent.

PubMed

Attallah, M F; Ahmed, I M; Hamed, Mostafa M

2013-02-01

The present work investigates the potential use of metal hydroxides sludge (MHS) generated from hot dipping galvanizing plant for adsorption of Congo Red and Naphthol Green B dyes from aqueous solutions. Characterization of MHS included infrared and X-ray fluorescence analysis. The effect of shaking time, initial dye concentration, temperature, adsorbent dosage and pH has been investigated. The results of adsorption experiments indicate that the maximum capacity of Congo Red and Naphthol Green B dyes at equilibrium (q(e)) and percentage of removal at pH 6 are 40 mg/g, 93 %, and 10 mg/g, 52 %, respectively. Some kinetic models were used to illustrate the adsorption process of Congo Red and Naphthol Green B dyes using MHS waste. Thermodynamic parameters such as (ΔG, ΔS, and ΔH) were also determined.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans

PubMed Central

Mellman, Thomas A.; Hall Brown, Tyish S.; Kobayashi, Ihori; Abu-Bader, Soleman H.; Lavela, Joseph; Altaee, Duaa; McLaughlin, Latesha; Randall, Otelio S.

2015-01-01

Background Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans. Purpose We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans. Methods One hundred thirty six Black, predominately African American, men and women with a mean age of 22.9 (SD = 4.6) filled out surveys, were interviewed and had two, 24-hour ambulatory BP recordings. Results Thirty eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures, correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance. Conclusions Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research. PMID:25623895

The Origin of High-angle Dip-slip Earthquakes at Geothermal Fields in California

NASA Astrophysics Data System (ADS)

Barbour, A. J.; Schoenball, M.; Martínez-Garzón, P.; Kwiatek, G.

2016-12-01

We examine the source mechanisms of earthquakes occurring in three California geothermal fields: The Geysers, Salton Sea, and Coso. We find source mechanisms ranging from strike slip faulting, consistent with the tectonic settings, to dip slip with unusually steep dip angles which are inconsistent with local structures. For example, we identify a fault zone in the Salton Sea Geothermal Field imaged using precisely-relocated hypocenters with a dip angle of 60° yet double-couple focal mechanisms indicate higher-angle dip-slip on ≥75° dipping planes. We observe considerable temporal variability in the distribution of source mechanisms. For example, at the Salton Sea we find that the number of high angle dip-slip events increased after 1989, when net-extraction rates were highest. There is a concurrent decline in strike-slip and strike-slip-normal faulting, the mechanisms expected from regional tectonics. These unusual focal mechanisms and their spatio-temporal patterns are enigmatic in terms of our understanding of faulting in geothermal regions. While near-vertical fault planes are expected to slip in a strike-slip sense, and dip slip is expected to occur on moderately dipping faults, we observe dip slip on near-vertical fault planes. However, for plausible stress states and accounting for geothermal production, the resolved fault planes should be stable. We systematically analyze the source mechanisms of these earthquakes using full moment tensor inversion to understand the constraints imposed by assuming a double-couple source. Applied to The Geysers field, we find a significant reduction in the number of high-angle dip-slip mechanisms using the full moment tensor. The remaining mechanisms displaying high-angle dip-slip could be consistent with faults accommodating subsidence and compaction associated with volumetric strain changes in the geothermal reservoir.

[Prevention of intramammary infections in dairy cows by the use of a premilking teat dip method with a foaming iodophor dip agent].

PubMed

Falkenberg, U; Tenhagen, B A; Baumgärtner, B; Heuwieser, W

2002-10-01

In this study we investigated the efficacy of premilking teat dipping with a foaming iodophor teat dip in a negative controlled field study. Incidence of new intramammary infections (IMI), incidence of clinical mastitis, influence on somatic cell count (SCC) and the characteristics of udder tissue and teats were used as parameters to evaluate clinical efficacy. Predipping was compared with a negative control using a split-udder experimental design. Right teats were predipped with a foaming disinfectant containing 0.27% iodine while left teats served as controls. The latter were conventionally cleaned with damp cloth towels and dried manually with disposable paper towels ("best cleaning practice"). All teats were dipped after milking with the same dip. There were no differences between treated and control quarters with respect to incidence of new IMI during the study period (treated quarters: 6.6% vs. untreated: 6.95%), incidence of clinical mastitis (30 cases in the treatment group vs. 39 cases in the control group) and geometric mean of SCC of quarter milk samples. Spectrum of detected pathogens was also comparable. Condition of udder tissue and teat ducts did not differ between treated and control quarters.

Performance evaluation of corrosion inhibitors and galvanized steel in concrete exposure specimens.

DOT National Transportation Integrated Search

1999-01-01

Corrosion inhibitor admixtures (CIA) and galvanized reinforcing steel (GS) are used for the corrosion protection for reinforced concrete bridges. The results of a 3.5-year evaluation of exposure specimens containing CIA from three different manufactu...

A finite-element simulation of galvanic coupling intra-body communication based on the whole human body.

PubMed

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.

A Finite-Element Simulation of Galvanic Coupling Intra-Body Communication Based on the Whole Human Body

PubMed Central

Song, Yong; Zhang, Kai; Hao, Qun; Hu, Lanxin; Wang, Jingwen; Shang, Fuzhou

2012-01-01

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. PMID:23202010

Multiple-Satellite Observation of Magnetic Dip Event During the Substorm on 10 October 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Zhaoguo; Chen, Lunjin; Zhu, Hui

Here, we present a multiple-satellite observation of the magnetic dip event during the substorm on 10 October 2013. The observation illustrates the temporal and spatial evolution of the magnetic dip and gives a compelling evidence that ring current ions induce the magnetic dip by enhanced plasma beta. The dip moves with the energetic ions in a comparable drift velocity and affects the dynamics of relativistic electrons in the radiation belt. In addition, the magnetic dip provides a favorable condition for the electromagnetic ion cyclotron (EMIC) wave generation based on the linear theory analysis. The calculated proton diffusion coefficients show thatmore » the observed EMIC wave can lead to the pitch angle scattering losses of the ring current ions, which in turn partially relax the magnetic dip in the observations. This study enriches our understanding of magnetic dip evolution and demonstrates the important role of the magnetic dip for the coupling of radiation belt and ring current.« less

Multiple-Satellite Observation of Magnetic Dip Event During the Substorm on 10 October 2013

NASA Astrophysics Data System (ADS)

He, Zhaoguo; Chen, Lunjin; Zhu, Hui; Xia, Zhiyang; Reeves, G. D.; Xiong, Ying; Xie, Lun; Cao, Yong

2017-09-01

We present a multiple-satellite observation of the magnetic dip event during the substorm on 10 October 2013. The observation illustrates the temporal and spatial evolution of the magnetic dip and gives a compelling evidence that ring current ions induce the magnetic dip by enhanced plasma beta. The dip moves with the energetic ions in a comparable drift velocity and affects the dynamics of relativistic electrons in the radiation belt. In addition, the magnetic dip provides a favorable condition for the electromagnetic ion cyclotron (EMIC) wave generation based on the linear theory analysis. The calculated proton diffusion coefficients show that the observed EMIC wave can lead to the pitch angle scattering losses of the ring current ions, which in turn partially relax the magnetic dip in the observations. This study enriches our understanding of magnetic dip evolution and demonstrates the important role of the magnetic dip for the coupling of radiation belt and ring current.

Multiple-Satellite Observation of Magnetic Dip Event During the Substorm on 10 October 2013

DOE PAGES

He, Zhaoguo; Chen, Lunjin; Zhu, Hui; ...

2017-09-05

Here, we present a multiple-satellite observation of the magnetic dip event during the substorm on 10 October 2013. The observation illustrates the temporal and spatial evolution of the magnetic dip and gives a compelling evidence that ring current ions induce the magnetic dip by enhanced plasma beta. The dip moves with the energetic ions in a comparable drift velocity and affects the dynamics of relativistic electrons in the radiation belt. In addition, the magnetic dip provides a favorable condition for the electromagnetic ion cyclotron (EMIC) wave generation based on the linear theory analysis. The calculated proton diffusion coefficients show thatmore » the observed EMIC wave can lead to the pitch angle scattering losses of the ring current ions, which in turn partially relax the magnetic dip in the observations. This study enriches our understanding of magnetic dip evolution and demonstrates the important role of the magnetic dip for the coupling of radiation belt and ring current.« less

A set of 14 DIP-SNP markers to detect unbalanced DNA mixtures.

PubMed

Liu, Zhizhen; Liu, Jinding; Wang, Jiaqi; Chen, Deqing; Liu, Zidong; Shi, Jie; Li, Zeqin; Li, Wenyan; Zhang, Gengqian; Du, Bing

2018-03-04

Unbalanced DNA mixture is still a difficult problem for forensic practice. DIP-STRs are useful markers for detection of minor DNA but they are not widespread in the human genome and having long amplicons. In this study, we proposed a novel type of genetic marker, termed DIP-SNP. DIP-SNP refers to the combination of INDEL and SNP in less than 300bp length of human genome. The multiplex PCR and SNaPshot assay were established for 14 DIP-SNP markers in a Chinese Han population from Shanxi, China. This novel compound marker allows detection of the minor DNA contributor with sensitivity from 1:50 to 1:1000 in a DNA mixture of any gender with 1 ng-10 ng DNA template. Most of the DIP-SNP markers had a relatively high probability of informative alleles with an average I value of 0.33. In all, we proposed DIP-SNP as a novel kind of genetic marker for detection of minor contributor from unbalanced DNA mixture and established the detection method by associating the multiplex PCR and SNaPshot assay. DIP-SNP polymorphisms are promising markers for forensic or clinical mixture examination because they are shorter, widespread and higher sensitive. Copyright © 2018 Elsevier Inc. All rights reserved.

DipTest: A litmus test for E. coli detection in water.

PubMed

Gunda, Naga Siva Kumar; Dasgupta, Saumyadeb; Mitra, Sushanta K

2017-01-01

We have developed a new litmus paper test (DipTest) for detecting Escherichia coli (E. coli) in water samples by performing enzymatic reactions directly on the porous paper substrate. The paper strip consists of a long narrow piece of cellulose blotting paper coated with chemoattractant (at bottom edge), wax hydrophobic barrier (at the top edge), and custom formulated chemical reagents (at reaction zone immediately below the wax hydrophobic barrier). When the paper strip is dipped in water, E. coli in the water sample is attracted toward the paper strip due to a chemotaxic mechanism followed by the ascent along the paper strip toward the reaction zone due to a capillary wicking mechanism, and finally the capillary motion is arrested at the top edge of the paper strip by the hydrophobic barrier. The E. coli concentrated at the reaction zone of the paper strip will react with custom formulated chemical reagents to produce a pinkish-red color. Such a color change on the paper strip when dipped into water samples indicates the presence of E. coli contamination in potable water. The performance of the DipTest device has been checked with different known concentrations of E. coli contaminated water samples using different dip and wait times. The DipTest device has also been tested with different interfering bacteria and chemical contaminants. It has been observed that the different interfering contaminants do not have any impact on the DipTest, and it can become a potential solution for screening water samples for E. coli contamination at the point of source.

DipTest: A litmus test for E. coli detection in water

PubMed Central

Gunda, Naga Siva Kumar; Dasgupta, Saumyadeb

2017-01-01

We have developed a new litmus paper test (DipTest) for detecting Escherichia coli (E. coli) in water samples by performing enzymatic reactions directly on the porous paper substrate. The paper strip consists of a long narrow piece of cellulose blotting paper coated with chemoattractant (at bottom edge), wax hydrophobic barrier (at the top edge), and custom formulated chemical reagents (at reaction zone immediately below the wax hydrophobic barrier). When the paper strip is dipped in water, E. coli in the water sample is attracted toward the paper strip due to a chemotaxic mechanism followed by the ascent along the paper strip toward the reaction zone due to a capillary wicking mechanism, and finally the capillary motion is arrested at the top edge of the paper strip by the hydrophobic barrier. The E. coli concentrated at the reaction zone of the paper strip will react with custom formulated chemical reagents to produce a pinkish-red color. Such a color change on the paper strip when dipped into water samples indicates the presence of E. coli contamination in potable water. The performance of the DipTest device has been checked with different known concentrations of E. coli contaminated water samples using different dip and wait times. The DipTest device has also been tested with different interfering bacteria and chemical contaminants. It has been observed that the different interfering contaminants do not have any impact on the DipTest, and it can become a potential solution for screening water samples for E. coli contamination at the point of source. PMID:28877199

Galvanic displacement reaction and rapid thermal annealing in size/shape controlling silver nanoparticles on silicon substrate

NASA Astrophysics Data System (ADS)

Ghosh, Tapas; Satpati, Biswarup

2017-05-01

The effect of the thermal annealing on silver nanoparticles deposited on silicon surface has been studied. The silver nanoparticles have been deposited by the galvanic displacement reaction. Rapid thermal annealing (RTA) has been performed on the Si substrate, containing the silver nanoparticles. The scanning transmission electron microscopy (STEM), energy dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM) study show that the galvanic displacement reaction and subsequent rapid thermal annealing could lead to well separated and spherical shaped larger silver nanoparticles on silicon substrate.

Galvanic coupling of steel and gold alloy lingual brackets with orthodontic wires.

PubMed

Polychronis, Georgios; Al Jabbari, Youssef S; Eliades, Theodore; Zinelis, Spiros

2018-03-06

The aim of this research was to assess galvanic behavior of lingual orthodontic brackets coupled with representative types of orthodontic wires. Three types of lingual brackets: Incognito (INC), In-Ovation L (IOV), and STb (STB) were combined with a stainless steel (SS) and a nickel-titanium (NiTi) orthodontic archwire. All materials were initially investigated by scanning electron microscopy / x-ray energy dispersive spectroscopy (SEM/EDX) while wires were also tested by x-ray diffraction spectroscopy (XRD). All bracket-wire combinations were immersed in acidic 0.1M NaCl 0.1M lactic acid and neutral NaF 0.3% (wt) electrolyte, and the potential differences were continuously recorded for 48 hours. The SEM/EDX analysis revealed that INC is a single-unit bracket made of a high gold (Au) alloy while IOV and STB are two-piece appliances in which the base and wing are made of SS alloys. The SS wire demonstrated austenite and martensite iron phase, while NiTi wire illustrated an intense austenite crystallographic structure with limited martensite. All bracket wire combinations showed potential differences below the threshold of galvanic corrosion (200 mV) except for INC and STB coupled with NiTi wire in NaF media. The electrochemical results indicate that all brackets tested demonstrated galvanic compatibility with SS wire, but fluoride treatment should be used cautiously with NiTi wires coupled with Au and SS brackets.

A&M. TAN607. Detail of installed hot shop viewing window almost ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. TAN-607. Detail of installed hot shop viewing window almost complete. Cable channel is still exposed, lacking cover. Note bottle in upper left corner containing spare zinc bromide in even of leak from window. Date: October 20, 1954. INEEL negative no. 12560 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Selective oxidation of dual phase steel after annealing at different dew points

NASA Astrophysics Data System (ADS)

Lins, Vanessa de Freitas Cunha; Madeira, Laureanny; Vilela, Jose Mario Carneiro; Andrade, Margareth Spangler; Buono, Vicente Tadeu Lopes; Guimarães, Juliana Porto; Alvarenga, Evandro de Azevedo

2011-04-01

Hot galvanized steels have been extensively used in the automotive industry. Selective oxidation on the steel surface affects the wettability of zinc on steel and the grain orientation of inhibition layer (Fe-Al-Zn alloy) and reduces the iron diffusion to the zinc layer. The aim of this work is to identify and quantify selective oxidation on the surface of a dual phase steel, and an experimental steel with a lower content of manganese, annealed at different dew points. The techniques employed were atomic force microscopy, X-ray photoelectron spectroscopy, and glow discharge optical emission spectroscopy. External selective oxidation was observed for phosphorus on steel surface annealed at 0 °C dp, and for manganese, silicon, and aluminum at a lower dew point. The concentration of manganese was higher on the dual phase steel surface than on the surface of the experimental steel. The concentration of molybdenum on the surface of both steels increased as the depth increased.

Galvanic Protection Of 2219 Al By Al/Li Powder

NASA Technical Reports Server (NTRS)

Daech, Alfred

1995-01-01

Coatings consisting of aluminum/lithium powders incorporated into acrylic resin found to protect panels of 2219 aluminum from corrosion by salt spray better than coating consisting of 2219 aluminum in same acrylic resin. Exact mechanism by which aluminum/lithium coatings protect against corrosion unknown, although galvanic mechanism suspected. These coatings (instead of chromium) applied to fasteners and bars to provide cathodic protection, both with and without impressed electrical current.

Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

PubMed Central

Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

2014-01-01

The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage.

PubMed

Hemilä, Harri

2017-05-01

To compare the efficacy of zinc acetate lozenges with zinc gluconate lozenges in common cold treatment and to examine the dose-dependency of the effect. Meta-analysis. Placebo-controlled zinc lozenge trials, in which the zinc dose was > 75 mg/day. The pooled effect of zinc lozenges on common cold duration was calculated by using inverse-variance random-effects method. Seven randomised trials with 575 participants with naturally acquired common colds. Duration of the common cold. The mean common cold duration was 33% (95% CI 21% to 45%) shorter for the zinc groups of the seven included trials. Three trials that used lozenges composed of zinc acetate found that colds were shortened by 40% and four trials that used zinc gluconate by 28%. The difference between the two salts was not significant: 12 percentage points (95% CI: -12 to + 36). Five trials used zinc doses of 80-92 mg/day, common cold duration was reduced by 33%, and two trials used zinc doses of 192-207 mg/day and found an effect of 35%. The difference between the high-dose and low-dose zinc trials was not significant: 2 percentage points (95% CI: -29 to + 32). Properly composed zinc gluconate lozenges may be as effective as zinc acetate lozenges. There is no evidence that zinc doses over 100 mg/day might lead to greater efficacy in the treatment of the common cold. Common cold patients may be encouraged to try zinc lozenges for treating their colds. The optimal lozenge composition and dosage scheme need to be investigated further.

Dietary phytate, zinc and hidden zinc deficiency.

PubMed

Sandstead, Harold H; Freeland-Graves, Jeanne H

2014-10-01

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

PubMed

Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

2015-12-01

A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

Host to Hot Jupiter

NASA Image and Video Library

2009-04-16

This image zooms into a small portion of NASA Kepler full field of view -- an expansive, 100-square-degree patch of sky in our Milky Way galaxy. At the center of the field is a star with a known "hot Jupiter" planet, named "TrES-2," zipping closely around it every 2.5 days. Kepler will observe TrES-2 and other known planets as a test to demonstrate that it is working properly, and to obtain new information about those planets. The area pictured is one-thousandth of Kepler's full field of view, and shows hundreds of stars at the very edge of the constellation Cygnus. The image has been color-coded so that brighter stars appear white, and fainter stars, red. It is a 60-second exposure, taken on April 8, 2009, one day after the spacecraft's dust cover was jettisoned. Kepler was designed to hunt for planets like Earth. The mission will spend the next three-and-a-half years staring at the same stars, looking for periodic dips in brightness. Such dips occur when planets cross in front of their stars from our point of view in the galaxy, partially blocking the starlight. To achieve the level of precision needed to spot planets as small as Earth, Kepler's images are intentionally blurred slightly. This minimizes the number of saturated stars. Saturation, or "blooming," occurs when the brightest stars overload the individual pixels in the detectors, causing the signal to spill out into nearby pixels. http://photojournal.jpl.nasa.gov/catalog/PIA11985

Zinc Enzymes.

ERIC Educational Resources Information Center

Bertini, I.; And Others

1985-01-01

Discusses the role of zinc in various enzymes concerned with hydration, hydrolysis, and redox reactions. The binding of zinc to protein residues, properties of noncatalytic zinc(II) and catalytic zinc, and the reactions catalyzed by zinc are among the topics considered. (JN)

Dynamic nanomechanical properties of novel Si-rich intermetallic coatings growth on a medical 316 LVM steel by hot dipping in a hypereutectic Al-25Si alloy.

PubMed

Frutos, E; González-Carrasco, J L

2015-06-01

This aim of this study is to determine the elastoplastic properties of Ni-free Al3FeSi2 intermetallic coatings grown on medical stainless steel under different experimental conditions. Elastoplastic properties are defined by the plasticity index (PI), which correlates the hardness and the Young's modulus. Special emphasis is devoted to correlate the PI with the wear resistance under sliding contact, determined by scratch testing, and fracture toughness, determined by using a novel method based on successive impacts with small loads. With regard to the substrate, the developed coatings are harder and exhibit a lower Young's reduced modulus, irrespective of the experimental conditions. It has been shown that preheating of the samples prior to hot dipping and immersion influences the type and volume fraction of precipitates, which in turn also affect the nanomechanical properties. The higher the preheating temperature is, the greater the Young's reduced modulus is. For a given preheating condition, an increase of the immersion time yields a decrease in hardness. Although apparent friction coefficients of coated specimens are smaller than those obtained on AISI 316 LVM, they increase when using preheating or higher immersion times during processing, which correlates with the PI. The presence of precipitates produces an increase in fracture toughness, with values greater than those presented by samples processed on melted AlSi alloys with lower Si content (12 wt%). Therefore, these intermetallic coatings could be considered "hard but tough", suitable to enhance the wear resistance, especially when using short periods of immersion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel Galvanic Corrosion Inhibitors: Synthesis, Characterization, Fabrication and Testing

DTIC Science & Technology

2007-09-30

have attempted to develop methods based on chemical structural modification to prevent galvanically-induced composite corrosion. [9, 10-12] These...of the two metallopolymers 11 and 12 show characteristic MLCT (metal-to-ligand charge transfer) absorption band of tris(bipyridyl)Ru(II) unit at k...showed absorption band at 450 nm and emission band at 325 nm of tris(bipyridyl)Ru(II) units in its respective UV-vis and fluorescence spectra. Very

Zinc

MedlinePlus

... Using toothpastes containing zinc, with or without an antibacterial agent, appears to prevent plaque and gingivitis. Some ... is some evidence that zinc has some antiviral activity against the herpes virus. Low zinc levels can ...

Hybrid Coatings Enriched with Tetraethoxysilane for Corrosion Mitigation of Hot-Dip Galvanized Steel in Chloride Contaminated Simulated Concrete Pore Solutions

PubMed Central

Figueira, Rita B.; Callone, Emanuela; Silva, Carlos J. R.; Pereira, Elsa V.; Dirè, Sandra

2017-01-01

Hybrid sol-gel coatings, named U(X):TEOS, based on ureasilicate matrices (U(X)) enriched with tetraethoxysilane (TEOS), were synthesized. The influence of TEOS addition was studied on both the structure of the hybrid sol-gel films as well as on the electrochemical properties. The effect of TEOS on the structure of the hybrid sol-gel films was investigated by solid state Nuclear Magnetic Resonance. The dielectric properties of the different materials were investigated by electrochemical impedance spectroscopy. The corrosion behavior of the hybrid coatings on HDGS was studied in chloride-contaminated simulated concrete pore solutions (SCPS) by polarization resistance measurements. The roughness of the HDGS coated with hybrids was also characterized by atomic force microscopy. The structural characterization of the hybrid materials proved the effective reaction between Jeffamine® and 3-isocyanate propyltriethoxysilane (ICPTES) and indicated that the addition of TEOS does not seem to affect the organic structure or to increase the degree of condensation of the hybrid materials. Despite the apparent lack of influence on the hybrids architecture, the polarization resistance measurements confirmed that TEOS addition improves the corrosion resistance of the hybrid coatings (U(X):TEOS) in chloride-contaminated SCPS when compared to samples prepared without any TEOS (U(X)). This behavior could be related to the decrease in roughness of the hybrid coatings (due TEOS addition) and to the different metal coating interaction resulting from the increase of the inorganic component in the hybrid matrix. PMID:28772667

Vertical Soil Profiling Using a Galvanic Contact Resistivity Scanning Approach

PubMed Central

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

2014-01-01

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. PMID:25057135

Product Quality Modelling Based on Incremental Support Vector Machine

NASA Astrophysics Data System (ADS)

Wang, J.; Zhang, W.; Qin, B.; Shi, W.

2012-05-01

Incremental Support vector machine (ISVM) is a new learning method developed in recent years based on the foundations of statistical learning theory. It is suitable for the problem of sequentially arriving field data and has been widely used for product quality prediction and production process optimization. However, the traditional ISVM learning does not consider the quality of the incremental data which may contain noise and redundant data; it will affect the learning speed and accuracy to a great extent. In order to improve SVM training speed and accuracy, a modified incremental support vector machine (MISVM) is proposed in this paper. Firstly, the margin vectors are extracted according to the Karush-Kuhn-Tucker (KKT) condition; then the distance from the margin vectors to the final decision hyperplane is calculated to evaluate the importance of margin vectors, where the margin vectors are removed while their distance exceed the specified value; finally, the original SVs and remaining margin vectors are used to update the SVM. The proposed MISVM can not only eliminate the unimportant samples such as noise samples, but also can preserve the important samples. The MISVM has been experimented on two public data and one field data of zinc coating weight in strip hot-dip galvanizing, and the results shows that the proposed method can improve the prediction accuracy and the training speed effectively. Furthermore, it can provide the necessary decision supports and analysis tools for auto control of product quality, and also can extend to other process industries, such as chemical process and manufacturing process.

A MS, SEM-EDX and XRD study of Ti or Cu-doped zinc ferrites as regenerable sorbents for hot coal gas desulfurization

NASA Astrophysics Data System (ADS)

Ahmed, M. A.; García, E.; Alonso, L.; Palacios, J. M.

2000-02-01

Kinetic studies in thermobalance carried out by several authors previously have shown that small concentrations of TiO 2 or CuO can increase substantially the overall sulfidation rate of zinc ferrites, as regenerable sorbents for hot coal gas desulfurization. These oxides modify the textural properties of both the fresh or regenerated and the sulfided sorbent, modifying consequently the sulfidation rate because it is a partially diffusion-controlled process. However, by using grain models it is shown that most of the observed changes are due to changes in the intrinsic reactivity of the sorbent. Detailed studies of characterization in previous papers using different techniques have failed in revealing differential chemical changes that could be associated with a different behavior. In fact, the only significant changes observed in these studies were an apparent disappearance in fresh sorbents calcined at very high temperatures of the Raman effect, and a slight shift of the XPS binding energy of Fe levels, indicating a probable site migration and/or a change of the oxidation state. These characterization results, however, were not completely conclusive and additional efforts should be undertaken. In this paper more sensitive techniques such as Mössbauer spectroscopy (MS), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDX), have been used for the characterization of fresh, regenerated and sulfided sorbents. The study shows that the addition of TiO 2 or CuO induce substantial structural changes in zinc ferrites that can explain their apparent enhancing effect on the overall sulfidation reactivity. Additionally, this effect is decreased as the number of sulfidation-regeneration cycles increases, probably explaining the performance decay exhibited by these sorbents in multicycle tests in a fixed bed reactor.

21 CFR 529.1044b - Gentamicin solution for dipping eggs.

Code of Federal Regulations, 2014 CFR

2014-04-01

....600(c) of this chapter. (c) Conditions of use in turkeys—(1) Amount. The drug is added to clean water...) Indications for use. As an aid in the reduction or elimination of the following microorganisms from turkey...) Limitations. For use in the dipping treatment of turkey-hatching eggs only. Eggs which have been dipped in the...

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

DOEpatents

Zaromb, Solomon; Lawson, Daniel B.

1994-01-01

A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

DOEpatents

Zaromb, S.; Lawson, D.B.

1994-02-15

A process for recovering zinc-rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered by distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10 C, separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream. 1 figure.

Experimental Modeling of Dynamic Shallow Dip-Slip Faulting

NASA Astrophysics Data System (ADS)

Uenishi, K.

2010-12-01

In our earlier study (AGU 2005, SSJ 2005, JPGU 2006), using a finite difference technique, we have conducted some numerical simulations related to the source dynamics of shallow dip-slip earthquakes, and suggested the possibility of the existence of corner waves, i.e., shear waves that carry concentrated kinematic energy and generate extremely strong particle motions on the hanging wall of a nonvertical fault. In the numerical models, a dip-slip fault is located in a two-dimensional, monolithic linear elastic half space, and the fault plane dips either vertically or 45 degrees. We have investigated the seismic wave field radiated by crack-like rupture of this straight fault. If the fault rupture, initiated at depth, arrests just below or reaches the free surface, four Rayleigh-type pulses are generated: two propagating along the free surface into the opposite directions to the far field, the other two moving back along the ruptured fault surface (interface) downwards into depth. These downward interface pulses may largely control the stopping phase of the dynamic rupture, and in the case the fault plane is inclined, on the hanging wall the interface pulse and the outward-moving Rayleigh surface pulse interact with each other and the corner wave is induced. On the footwall, the ground motion is dominated simply by the weaker Rayleigh pulse propagating along the free surface because of much smaller interaction between this Rayleigh and the interface pulse. The generation of the downward interface pulses and corner wave may play a crucial role in understanding the effects of the geometrical asymmetry on the strong motion induced by shallow dip-slip faulting, but it has not been well recognized so far, partly because those waves are not expected for a fault that is located and ruptures only at depth. However, the seismological recordings of the 1999 Chi-Chi, Taiwan, the 2004 Niigata-ken Chuetsu, Japan, earthquakes as well as a more recent one in Iwate-Miyagi Inland

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

ERIC Educational Resources Information Center

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…

[Improvement in zinc nutrition due to zinc transporter-targeting strategy].

PubMed

Kambe, Taiho

2016-07-01

Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health.

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

PubMed

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 Fe 3 O 4 or α-Fe 2 O 3 or field-extracted Fe 3 O 4 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 UV 254 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.

Deposition of zinc sulfide thin films by chemical bath process

NASA Astrophysics Data System (ADS)

Oladeji, Isaiah O.; Chow, Lee

1996-11-01

Deposition of high quality zinc sulfide (ZnS) thin film over a large area is required if it is to be effectively used in electroluminescent devices, solar cells, and other optoelectronic devices. Of all deposition techniques, chemical bath deposition (CBD) is the least costly technique that meets the above requirements. Recently it is found that the growth of ZnS film, of thickness less than 100 nm in a single dip, by CBD is facilitated by the use of ammonia and hydrazine as complexing agents. Here we report that the thickness of the deposited ZnS film can be increased if ammonium salt is used as a buffer. We also present an analytical study to explain our results and to further understand the ZnS growth process in CBD.

Pseudomonas aeruginosa mastitis in two goats associated with an essential oil-based teat dip.

PubMed

Kelly, E Jane; Wilson, David J

2016-11-01

Pseudomonas aeruginosa is an opportunistic pathogen that has been associated with mastitis in dairy animals, including goats. Often, the environmental sources of the bacteria are water-related (such as hoses and muddy pastures). Mastitis attributable to P. aeruginosa was identified in 2 goats in a small herd. Efforts were made to identify environmental sources of the pathogen. Multiple samples from the goats' environment were cultured, including water from the trough, bedding, the hose used to wash udders, and the teat dip and teat dip containers. The bacterium was isolated from the teat dip and the teat dip container. The teat dip consisted of water, liquid soap, and several drops of essential oils (including tea tree, lavender, and peppermint). This case illustrates a potential problem that may arise as a result of the use of unconventional ingredients in teat dips. The use of alternative products by goat producers is likely to increase in the future. © 2016 The Author(s).

Press-hardening of zinc coated steel - characterization of a new material for a new process

NASA Astrophysics Data System (ADS)

Kurz, T.; Larour, P.; Lackner, J.; Steck, T.; Jesner, G.

2016-11-01

Press-hardening of zinc-coated PHS has been limited to the indirect process until a pre-cooling step was introduced before the hot forming to prevent liquid metal embrittlement. Even though that's only a minor change in the process itself it does not only eliminate LME, but increases also the demands on the base material especially in terms of hardenability or phase transformations at temperatures below 700 °C in general. This paper deals with the characterization of a modified zinc-coated material for press-hardening with pre-cooling that assures a robust process. The pre-cooling step itself and especially the transfer of the blank in the hot-forming die is more demanding than the standard 22MnB5 can stand to ensure full hardenability. Therefore the transformation behavior of the modified material is shown in CCT and TTT diagrams. Of the same importance are the changed hot forming temperature and flow curves for material at lower temperatures than typically used in direct hot forming. The resulting mechanical properties after hardening from tensile testing and bending tests are shown in detail. Finally some results from side impact crash tests and correlations of the findings with mechanical properties such as fracture elongation, tensile strength, VDA238 bending angle at maximum force as well as postuniform bending slope are given as well. Fracture elongation is shown to be of little help for damage prediction in side impact crash. Tensile strength and VDA bending properties enable however some accurate prediction of the PHS final damage behavior in bending dominated side impact load case.

Pulse Profiles, Accretion Column Dips and a Flare in GX 1+4 During a Faint State

NASA Technical Reports Server (NTRS)

Giles, A. B.; Galloway, D. K.; Greenhill, J. G.; Storey, M. C.; Wilson, C. A.

1999-01-01

The Rossi X-ray Timing Explorer (RXTE) spacecraft observed the X-ray GX 1+4 for it period of 34 hours on July 19/20 1996. The source faded front an intensity of approximately 20 mcrab to a minimum of <= 0.7 mcrab and then partially recovered towards the end of the observation. This extended minimum lasted approximately 40,000 seconds. Phase folded light curves at a barycentric rotation period of 124.36568 +/- 0.00020 seconds show that near the center of the extended minimum the source stopped pulsing in the traditional sense but retained a weak dip feature at the rotation period. Away from the extended minimum the dips are progressively narrower at higher energies and may be interpreted as obscurations or eclipses of the hot spot by the accretion column. The pulse profile changed from leading-edge bright before the extended minimum to trailing-edge bright after it. Data from the Burst and Transient Source Experiment (BATSE) show that a torque reversal occurred < 10 days after our observation. Our data indicate that the observed rotation departs from a constant period with a P/P value of approximately -1.5% per year at a 4.5sigma significance. We infer that we may have serendipitously obtained data, with high sensitivity and temporal resolution about the time of an accretion disk spin reversal. We also observed a rapid flare which had some precursor activity close to the center of the extended minimum.

Improved zinc electrode and rechargeable zinc-air battery

DOEpatents

Ross, P.N. Jr.

1988-06-21

The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

DIP1 modulates stem cell homeostasis in Drosophila through regulation of sisR-1.

PubMed

Wong, Jing Ting; Akhbar, Farzanah; Ng, Amanda Yunn Ee; Tay, Mandy Li-Ian; Loi, Gladys Jing En; Pek, Jun Wei

2017-10-02

Stable intronic sequence RNAs (sisRNAs) are by-products of splicing and regulate gene expression. How sisRNAs are regulated is unclear. Here we report that a double-stranded RNA binding protein, Disco-interacting protein 1 (DIP1) regulates sisRNAs in Drosophila. DIP1 negatively regulates the abundance of sisR-1 and INE-1 sisRNAs. Fine-tuning of sisR-1 by DIP1 is important to maintain female germline stem cell homeostasis by modulating germline stem cell differentiation and niche adhesion. Drosophila DIP1 localizes to a nuclear body (satellite body) and associates with the fourth chromosome, which contains a very high density of INE-1 transposable element sequences that are processed into sisRNAs. DIP1 presumably acts outside the satellite bodies to regulate sisR-1, which is not on the fourth chromosome. Thus, our study identifies DIP1 as a sisRNA regulatory protein that controls germline stem cell self-renewal in Drosophila.Stable intronic sequence RNAs (sisRNAs) are by-products of splicing from introns with roles in embryonic development in Drosophila. Here, the authors show that the RNA binding protein DIP1 regulates sisRNAs in Drosophila, which is necessary for germline stem cell homeostasis.

Bench-scale demonstration of hot-gas desulfurization technology. Quarterly report, April 1 - June 30, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-12-31

The US Department of Energy (DOE) Morgantown Energy Technology Center (METC) is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal gas) streams of integrated gasification combined-cycle (IGCC) power systems. The programs focus on hot-gas particulate removal and desulfurization technologies that match or nearly match the temperatures and pressures of the gasifier, cleanup system, and power generator. The work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. The goal of this project is to continue further development of the zinc titanate desulfurizationmore » and direct sulfur recovery process (DSRP) technologies by (1) scaling up the zinc titanate reactor system; (2) developing an integrated skid-mounted zinc titanate desulfurization-DSRP reactor system; (3) testing the integrated system over an extended period with real coal-as from an operating gasifier to quantify the degradative effect, if any, of the trace contaminants present in cola gas; (4) developing an engineering database suitable for system scaleup; and (5) designing, fabricating and commissioning a larger DSRP reactor system capable of operating on a six-fold greater volume of gas than the DSRP reactor used in the bench-scale field test. The work performed during the April 1 through June 30, 1996 period is described.« less

Effects of temperature and operation parameters on the galvanic corrosion of Cu coupled to Au in organic solderability preservatives process

NASA Astrophysics Data System (ADS)

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.

The Dip. H.E. Coombe Lodge Report, Study Confererence 74/43.

ERIC Educational Resources Information Center

Further Education Staff Coll., Blagdon (England).

Papers presented on the Dip. H.E., a two-year course in higher education recently developed in Britain include: the future of higher education (W. Taylor); the colleges of education perspective on the Dip. H.E. (N. Payne); the colleges of further education perspective (W. Bosley); the polytechnics perspective (A. Sandbach); validating the diploma…

Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

PubMed

Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

2016-09-01

The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

Galvanic Liquid Applied Coating Development for Protection of Steel in Concrete

NASA Technical Reports Server (NTRS)

Curran, Joseph John; Curran, Jerry; MacDowell, Louis

2004-01-01

Corrosion of reinforcing steel in concrete is a major problem affecting NASA facilities at Kennedy Space Center (KSC), other government agencies, and the general public. Problems include damage to KSC launch support structures, transportation and marine infrastructures, as well as building structures. A galvanic liquid applied coating was developed at KSC in order to address this problem. The coating is a non-epoxy metal rich ethyl silicate liquid coating. The coating is applied as a liquid from initial stage to final stage. Preliminary data shows that this coating system exceeds the NACE 100 millivolt shift criterion. The remainder of the paper details the development of the coating system through the following phases: Phase I: Development of multiple formulations of the coating to achieve easy application characteristics, predictable galvanic activity, long-term protection, and minimum environmental impact. Phase II: Improvement of the formulations tested in Phase I including optimization of metallic loading as well as incorporation of humectants for continuous activation. Phase III: Application and testing of improved formulations on the test blocks. Phase IV: Incorporation of the final formulation upgrades onto large instrumented structures (slabs).

29 CFR 1910.123 - Dipping and coating operations: Coverage and definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... tank containing a liquid other than water. It applies when you use the liquid in the tank or its vapor... combustion, independent of any other source of heat. Dip tank means a container holding a liquid other than... dip tank or it may be suspended in a vapor coming from the tank. Flammable liquid means any liquid...

Method of capturing or trapping zinc using zinc getter materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunyadi Murph, Simona E.; Korinko, Paul S.

2017-07-11

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

Synthesis of active absorber layer by dip-coating method for perovskite solar cell

NASA Astrophysics Data System (ADS)

Singh, Rahul; Noor, I. M.; Singh, Pramod K.; Bhattacharya, B.; Arof, A. K.

2018-04-01

In this paper, we develop the hybrid perovskite-based n-i-p solar cell using a simple, fast and low-cost dip-coating method. Hot solution and the pre-annealed substrate are used for coating the perovskite thin film by this method this is further used for studying its structural and electrical properties. UV-vis spectroscopy is carried out for calculating the band gap of the hybrid perovskite layer which is ∼1.6 eV. X-ray spectroscopy confirms that the formation of hybrid perovskite layer. The profilometer is used to study the surface roughness and also for measuring the thickness of the perovskite layer with varying substrate temperature. The optimized sample was further used for cross-sectional SEM image to verify the thickness measured from the profiler. The electrical parameter of JV characteristic with varying temperature is tabulated in the table. Whereas, the perovskite sensitized solar cell exhibits highest short circuit current density, Jsc of 11 mA cm-2, open circuit voltage, Voc of 0.87 V, fill factor of 0.55 and efficiency, η of >5%.

Development of flow-through and dip-stick immunoassays for screening of sulfonamide residues.

PubMed

Zhang, Hongyan; Zhang, Yan; Wang, Shuo

2008-08-20

Two formats of membrane-based competitive enzyme immunoassays (flow-through and dip-stick) have been developed for the screening of sulfonamide residues in pig muscle and milk. Membrane was coated with anti-sulfonamide antibody and a sulfonamide hapten D2-horseradish peroxidase (HRP) conjugant was used as the labeled antigen for competitive assay of sulfonamides. Visual detection limits of the flow-through or dip-stick assay were 1-5 microg L(-1) or 1-10 microg L(-1) in buffer for seven sulfonamides, respectively. Assay validation was performed using samples spiked with single sulfonamide, spiked samples were tested using the developed strip assays and results were compared with those obtained by a validated high-performance liquid chromatograph (HPLC) method. Results showed that the two strip assays were correlated well with HPLC, respectively. With assay times of 5 min (flow-through) and 15 min (dip-stick), these rapid tests could offer simple, rapid and cost-effective on-site screening tools to detect sulfonamides in pig muscle (flow-through or dip-stick) or milk (only dip-stick).

29 CFR 1910.124 - General requirements for dipping and coating operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... below 25% of its LFL. (2) When a liquid in a dip tank creates an exposure hazard covered by a standard... may use a tank cover or material that floats on the surface of the liquid in a dip tank to replace or... must: (1) Inspect the hoods and ductwork of the ventilation system for corrosion or damage: (i) At...

Drinking with a hairy tongue: viscous entrainment by dipping hairy surfaces

NASA Astrophysics Data System (ADS)

Nasto, Alice; Brun, Pierre-Thomas; Alvarado, José; Bush, John; Hosoi, Anette

2016-11-01

Nectar-drinking bats have tongues covered with hair-like papillae, enhancing their ability to take up viscous nectar by dipping. Using a combination of model experiments and theory reminiscent of Landau-Levich-Derjaguin dip coating, we rationalize this mechanism of viscous entrainment in a hairy texture. For the model experiments, hairy surfaces are fabricated using laser cut molds and casting samples with PDMS elastomer. Modeling the liquid trapped within the texture using a Darcy-Brinkman like approach, we derive the drainage flow solution. The amount of fluid that is entrained is dependent on the viscosity of the fluid, the density of the hairs, and the dipping speed. We find that there is an optimal hair density to maximize fluid uptake.

Change of Hot Cracking Susceptibility in Welding of High Strength Aluminum Alloy AA 7075

NASA Astrophysics Data System (ADS)

Holzer, M.; Hofmann, K.; Mann, V.; Hugger, F.; Roth, S.; Schmidt, M.

High strength aluminum alloys are known as hard to weld alloys due to their high hot crack susceptibility. However, they have high potential for applications in light weight constructions of automotive industry and therefore it is needed to increase weldability. One major issue is the high hot cracking susceptibility. Vaporization during laser beam welding leads to a change of concentration of the volatile elements magnesium and zinc. Hence, solidification range of the weld and therefore hot cracking susceptibility changes. Additionally, different welding velocities lead to changed solidification conditions with certain influence on hot cracking. This paper discusses the influence of energy per unit length during laser beam welding of AA 7075 on the change of element concentration in the weld seam and the resulting influence on hot cracking susceptibility. Therefore EDS-measurements of weld seams generated with different velocities are performed to determine the change of element concentration. These quantitative data is used to numerically calculate the solidification range in order to evaluate its influence on the hot cracking susceptibility. Besides that, relative hot crack length and mechanical properties are measured. The results increase knowledge about welding of high strength aluminum alloy AA 7075 and hence support further developing of the welding process.

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

NASA Astrophysics Data System (ADS)

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

2017-06-01

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

Zinc in human health: effect of zinc on immune cells.

PubMed

Prasad, Ananda S

2008-01-01

Although the essentiality of zinc for plants and animals has been known for many decades, the essentiality of zinc for humans was recognized only 40 years ago in the Middle East. The zinc-deficient patients had severe immune dysfunctions, inasmuch as they died of intercurrent infections by the time they were 25 years of age. In our studies in an experimental human model of zinc deficiency, we documented decreased serum testosterone level, oligospermia, severe immune dysfunctions mainly affecting T helper cells, hyperammonemia, neurosensory disorders, and decreased lean body mass. It appears that zinc deficiency is prevalent in the developing world and as many as two billion subjects may be growth retarded due to zinc deficiency. Besides growth retardation and immune dysfunctions, cognitive impairment due to zinc deficiency also has been reported recently. Our studies in the cell culture models showed that the activation of many zinc-dependent enzymes and transcription factors were adversely affected due to zinc deficiency. In HUT-78 (T helper 0 [Th(0)] cell line), we showed that a decrease in gene expression of interleukin-2 (IL-2) and IL-2 receptor alpha(IL-2Ralpha) were due to decreased activation of nuclear factor-kappaB (NF-kappaB) in zinc deficient cells. Decreased NF-kappaB activation in HUT-78 due to zinc deficiency was due to decreased binding of NF-kappaB to DNA, decreased level of NF-kappaB p105 (the precursor of NF-kappaB p50) mRNA, decreased kappaB inhibitory protein (IkappaB) phosphorylation, and decreased Ikappa kappa. These effects of zinc were cell specific. Zinc also is an antioxidant and has anti-inflammatory actions. The therapeutic roles of zinc in acute infantile diarrhea, acrodermatitis enteropathica, prevention of blindness in patients with age-related macular degeneration, and treatment of common cold with zinc have been reported. In HL-60 cells (promyelocytic leukemia cell line), zinc enhances the up-regulation of A20 mRNA, which, via TRAF

Effect of Sm-Rich Phase on Corrosion Behavior of Hot-Extruded AZ31-1.5Sm Magnesium Alloy

NASA Astrophysics Data System (ADS)

Li, Xiao; Hu, Zhi; Yan, Hong; Wu, Xiaoquan; Xie, Hecong; Dong, Zhou

2018-05-01

The effects of Sm on the corrosion and microstructure behavior of hot-extruded AZ31 magnesium alloy were investigated by SEM, TEM, weight loss analysis, and electrochemical measurements. The results indicated that granular Al2Sm phase 4 μm in size in the hot-extruded AZ31 magnesium alloy modified with 1.5 wt.% Sm leads to significant grain refinement. The corrosion rate decreased from 15.98 × 10-4 to 11.19 × 10-4 g cm-2 h-1 in the transverse section and from 8.57 × 10-4 to 6.20 × 10-4 g cm-2 h-1 in the longitudinal section. Compared to the unmodified alloy, the corrosion potential of the Sm-modified alloy in the transverse and longitudinal sections increased by 98 and 62 mV, respectively, and the R ct value (charge transfer resistance) in the transverse and longitudinal sections of the modified alloy increased from 1764 and 1756 to 2928 and 2408 Ω cm2, respectively. The results showed that the corrosion resistance of hot-extruded AZ31 magnesium alloy was significantly improved by Sm addition due to the grain refinement, the decreased dislocation density, and the suppression of micro-galvanic corrosion caused by Al-Sm-(Mn) intermetallic compounds.

Anticorrosive Behavior and Porosity of Tricationic Phosphate and Zirconium Conversion Coating on Galvanized Steel

NASA Astrophysics Data System (ADS)

Velasquez, Camilo S.; Pimenta, Egnalda P. S.; Lins, Vanessa F. C.

2018-05-01

This work evaluates the corrosion resistance of galvanized steel treated with tricationic phosphate and zirconium conversion coating after painting, by using electrochemical techniques, accelerated and field corrosion tests. A non-uniform and heterogeneous distribution of zirconium on the steel surface was observed due to preferential nucleation of the zirconium on the aluminum-rich sites on the surface of galvanized steel. The long-term anti-corrosion performance in a saline solution was better for the phosphate coating up to 120 days. The coating capacitance registered a higher increase for the zirconium coatings than the phosphate coatings up to 120 days of immersion. This result agrees with the higher porosity of zirconium coating in relation to the phosphate coating. After 3840 h of accelerated corrosion test, and after 1 year of accelerated field test, zirconium-treated samples showed an average scribe delamination length higher than the phosphate-treated samples.

Anticorrosive Behavior and Porosity of Tricationic Phosphate and Zirconium Conversion Coating on Galvanized Steel

NASA Astrophysics Data System (ADS)

Velasquez, Camilo S.; Pimenta, Egnalda P. S.; Lins, Vanessa F. C.

2018-04-01

This work evaluates the corrosion resistance of galvanized steel treated with tricationic phosphate and zirconium conversion coating after painting, by using electrochemical techniques, accelerated and field corrosion tests. A non-uniform and heterogeneous distribution of zirconium on the steel surface was observed due to preferential nucleation of the zirconium on the aluminum-rich sites on the surface of galvanized steel. The long-term anti-corrosion performance in a saline solution was better for the phosphate coating up to 120 days. The coating capacitance registered a higher increase for the zirconium coatings than the phosphate coatings up to 120 days of immersion. This result agrees with the higher porosity of zirconium coating in relation to the phosphate coating. After 3840 h of accelerated corrosion test, and after 1 year of accelerated field test, zirconium-treated samples showed an average scribe delamination length higher than the phosphate-treated samples.

Evaporatively cooled chiller for solar air conditioning systems design and field test

NASA Astrophysics Data System (ADS)

Merrick, R. H.; Murray, J. G.

1984-06-01

Design changes to improve reliability, part load performance, and manufacturability characteristics of the chiller are focused upon. Low heat flux was achieved by large transfer area allows scale formation without being a thermal barrier: 80 mils = 1 deg. The scaling rate is minimized by keeping surface temperatures below 100 F and a generous water recirculation flow rate. By integrating the cooling tower function into the chiller itself parasitic power consumption was reduced 35%. This system also provided the winter freeze protection without the specific manual shut down procedures required by separate water cooled units and their towers. The severe reduction in cumulative coefficient of performance (COP) due to cycling conditions has been substantially reduced using the spin down control scheme. The major disappointment was the failure to develop a satisfactory inexpensive protective coating. Hot dip galvanizing was demonstrated to be effective but costly, partially due to transportation expense.

The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

PubMed Central

Geiser, Jim; De Lisle, Robert C.; Andrews, Glen K.

2013-01-01

Background ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. Methods/Principal Findings We created mice with floxed Zip5 genes and deleted this gene in the entire mouse or specifically in enterocytes or acinar cells and then examined the effects on zinc homeostasis. We found that ZIP5 is not essential for growth and viability but total knockout of ZIP5 led to increased zinc in the liver in mice fed a zinc-adequate (ZnA) diet but impaired accumulation of pancreatic zinc in mice fed a zinc-excess (ZnE) diet. Loss-of-function of enterocyte ZIP5, in contrast, led to increased pancreatic zinc in mice fed a ZnA diet and increased abundance of intestinal Zip4 mRNA. Finally, loss-of-function of acinar cell ZIP5 modestly reduced pancreatic zinc in mice fed a ZnA diet but did not impair zinc uptake as measured by the rapid accumulation of 67zinc. Retention of pancreatic 67zinc was impaired in these mice but the absence of pancreatic ZIP5 sensitized them to zinc-induced pancreatitis and exacerbated the formation of large cytoplasmic vacuoles containing secretory protein in acinar cells. Conclusions These studies demonstrate that ZIP5 participates in the control of zinc excretion in mice. Specifically, they reveal a paramount function of intestinal ZIP5 in zinc excretion but suggest a role for pancreatic ZIP5 in zinc accumulation/retention in acinar cells. ZIP5 functions in acinar cells to protect against zinc-induced acute pancreatitis and attenuate the process of zymophagy. This suggests that it may play a role in autophagy. PMID:24303081

NITRIC ACID PICKLING PROCESS

DOEpatents

Boller, E.R.; Eubank, L.D.

1958-08-19

An improved process is described for the treatment of metallic uranium surfaces preparatory to being given hot dip coatings. The process consists in first pickling the uraniunn surInce with aqueous 50% to 70% nitric acid, at 60 to 70 deg C, for about 5 minutes, rinsing the acid solution from the uranium article, promptly drying and then passing it through a molten alkali-metal halide flux consisting of 42% LiCl, 53% KCla and 5% NaCl into a molten metal bath consisting of 85 parts by weight of zinc and 15 parts by weight of aluminum

Continentward-Dipping Normal Faults, Boudinage and Ductile Shear at Rifted Passive Margins

NASA Astrophysics Data System (ADS)

Clerc, C. N.; Ringenbach, J. C.; Jolivet, L.; Ballard, J. F.

2017-12-01

Deep structures resulting from the rifting of the continental crust are now well imaged by seismic profiles. We present a series of recent industrial profiles that allow the identification of various rift-related geological processes such as crustal boudinage, ductile shear of the base of the crust and low-angle detachment faulting. Along both magma-rich and magma-poor rifted margins, we observe clear indications of ductile deformation of the deep continental crust. Large-scale shallow dipping shear zones are identified with a top-to-the-continent sense of shear. This sense of shear is consistent with the activity of the Continentward-Dipping Normal Faults (CDNF) that accommodate the extension in the upper crust. This pattern is responsible for an oceanward migration of the deformation and of the associated syn-tectonic deposits (sediments and/or volcanics). We discuss the origin of the Continentward-Dipping Normal Faults (CDNF) and investigate their implications and the effect of sediment thermal blanketing on crustal rheology. In some cases, low-angle shear zones define an anastomosed pattern that delineates boudin-like structures that seem to control the position and dip of upper crustal normal faults. We present some of the most striking examples from several locations (Uruguay, West Africa, South China Sea…), and discuss their rifting histories that differ from the classical models of oceanward-dipping normal faults.

9 CFR 72.13 - Permitted dips and procedures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... eradication of ticks, APHIS will require that the product be registered under the provisions of the Federal... will effectually eradicate ticks without injury to the animals dipped. (d) Tissue residues; restriction...

9 CFR 72.13 - Permitted dips and procedures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... eradication of ticks, APHIS will require that the product be registered under the provisions of the Federal... will effectually eradicate ticks without injury to the animals dipped. (d) Tissue residues; restriction...

Optical properties of titanium di-oxide thin films prepared by dip coating method

NASA Astrophysics Data System (ADS)

Biswas, Sayari; Rahman, Kazi Hasibur; Kar, Asit Kumar

2018-05-01

Titanium dioxide (TiO2) thin films were prepared by sol-gel dip coating method on ITO coated glass substrate. The sol was synthesized by hydrothermal method at 90°C. The sol was then used to make TiO2 films by dip coating. After dip coating the rest of the sol was dried at 100°C to make TiO2 powder. Thin films were made by varying the number of dipping cycles and were annealed at 500°C. XRD study was carried out for powder samples that confirms the formation of anatase phase. Transmission spectra of thin films show sharp rise in the violet-ultraviolet transition region and a maximum transmittance of ˜60%. Band gap of the prepared films varies from 3.15 eV to 3.22 eV.

Zinc pharmacokinetic parameters in the determination of body zinc status in children.

PubMed

Vale, S H L; Leite, L D; Alves, C X; Dantas, M M G; Costa, J B S; Marchini, J S; França, M C; Brandão-Neto, J

2014-02-01

Serum or tissue zinc concentrations are often used to assess body zinc status. However, all of these methods are relatively inaccurate. Thus, we investigated three different kinetic methods for the determination of zinc clearance to establish which of these could detect small changes in the body zinc status of children. Forty apparently healthy children were studied. Renal handling of zinc was investigated during intravenous zinc administration (0.06537 mg Zn/kg of body weight), both before and after oral zinc supplementation (5 mg Zn/day for 3 months). Three kinetic methods were used to determine zinc clearance: CZn-Formula A and CZn-Formula B were both used to calculate systemic clearance; the first is a general formula and the second is used for the specific analysis of a single-compartment model; CZn-Formula C is widely used in medical practices to analyze kinetic routine. Basal serum zinc values, which were within the reference range for healthy children, increased significantly after oral zinc supplementation. The three formulas used gave different results for zinc clearance both before and after oral zinc supplementation. CZn-Formula B showed a positive correlation with basal serum zinc concentration after oral supplementation (R2=0.1172, P=0.0306). In addition, CZn-Formula B (P=0.0002) was more effective than CZn-Formula A (P=0.6028) and CZn-Formula C (P=0.0732) in detecting small variations in body zinc status. All three of the formulas used are suitable for studying zinc kinetics; however, CZn-Formula B is particularly effective at detecting small changes in body zinc status in healthy children.

Morphology control of zinc regeneration for zinc-air fuel cell and battery

NASA Astrophysics Data System (ADS)

Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

2014-12-01

Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

Zinc and Autophagy

PubMed Central

Liuzzi, Juan P.; Guo, Liang; Yoo, Changwon; Stewart, Tiffanie S

2014-01-01

Autophagy is a highly conserved degradative process through which cells overcome stressful conditions. Inasmuch as faulty autophagy has been associated with aging, neuronal degeneration disorders, diabetes, and fatty liver, autophagy is regarded as a potential therapeutic target. This review summarizes the present state of knowledge concerning the role of zinc in the regulation of autophagy, the role of autophagy in zinc metabolism, and the potential role of autophagy as a mediator of the protective effects of zinc. Data from in vitro studies consistently support the notion that zinc is critical for early and late autophagy. Studies have shown inhibition of early and late autophagy in cells cultured in medium treated with zinc chelators. Conversely, excess zinc added to the medium has shown to potentiate the stimulation of autophagy by tamoxifen, H2O2, ethanol and dopamine. The potential role of autophagy in zinc homeostasis has just begun to be investigated.Increasing evidence indicates that autophagy dysregulation causes significant changes in cellular zinc homeostasis. Autophagy may mediate the protective effect of zinc against lipid accumulation, apoptosis and inflammation by promoting degradation of lipid droplets, inflammasomes, p62/SQSTM1 and damaged mitochondria.Studies with humans and animal models are necessary to determine whether autophagy is influenced by zinc intake. PMID:25012760

A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc.

PubMed

Wastney, Meryl E; McDonald, Christine M; King, Janet C

2018-05-01

Zinc deficiency limits infant growth and increases susceptibility to infections, which further compromises growth. Zinc supplementation improves the growth of zinc-deficient stunted infants, but the amount, frequency, and duration of zinc supplementation required to restore growth in an individual child is unknown. A dynamic model of zinc metabolism that predicts changes in weight and length of zinc-deficient, stunted infants with dietary zinc would be useful to define effective zinc supplementation regimens. The aims of this study were to develop a dynamic model for zinc metabolism in stunted, zinc-deficient infants and to use that model to predict the growth response when those infants are given zinc supplements. A model of zinc metabolism was developed using data on zinc kinetics, tissue zinc, and growth requirements for healthy 9-mo-old infants. The kinetic model was converted to a dynamic model by replacing the rate constants for zinc absorption and excretion with functions for these processes that change with zinc intake. Predictions of the dynamic model, parameterized for zinc-deficient, stunted infants, were compared with the results of 5 published zinc intervention trials. The model was then used to predict the results for zinc supplementation regimes that varied in the amount, frequency, and duration of zinc dosing. Model predictions agreed with published changes in plasma zinc after zinc supplementation. Predictions of weight and length agreed with 2 studies, but overpredicted values from a third study in which other nutrient deficiencies may have been growth limiting; the model predicted that zinc absorption was impaired in that study. The model suggests that frequent, smaller doses (5-10 mg Zn/d) are more effective for increasing growth in stunted, zinc-deficient 9-mo-old infants than are larger, less-frequent doses. The dose amount affects the duration of dosing necessary to restore and maintain plasma zinc concentration and growth.

Effect of Hot Rolling Process on Microstructure and Properties of Low-Carbon Al-Killed Steels Produced Through TSCR Technology

NASA Astrophysics Data System (ADS)

Paul, S. K.; Ahmed, U.; Megahed, G. M.

2011-10-01

Low-carbon Al-killed hot rolled strips for direct forming, cold rolling, and galvanizing applications are produced from the similar chemistry at Ezz Flat Steel (EFS) through thin slab casting and rolling (TSCR) technology. The desired mechanical and microstructural properties in hot bands for different applications are achieved through control of hot rolling parameters, which in turn control the precipitation and growth of AlN. Nitrogen in solid solution strongly influences the yield strength (YS), ductility, strain aging index (SAI), and other formability properties of steel. The equilibrium solubility of AlN in austenite at different temperatures and its isothermal precipitation have been studied. To achieve the formability properties for direct forming, soluble nitrogen is fixed as AlN by coiling the strip at higher temperatures. For stringent cold forming, boron was added below the stoichiometric ratio with nitrogen, which improved the formability properties dramatically. The requirements of hot band for processing into cold rolled and annealed deep drawing sheets are high SAI and fine-grain microstructure. Higher finish rolling and low coiling temperatures are used to achieve these. Fully processed cold rolled sheets from these hot strips at customer's end have shown good formability properties. Coil break marks observed in some coils during uncoiling were found to be associated with yielding phenomenon. The spike height (difference between upper and lower yield stresses) and yield point elongation (YPE) were found to be the key material parameters for the break marks. Factors affecting these parameters have been studied and the coiling temperature optimized to overcome the problem.

Genetic fine-mapping of DIPLOSPOROUS in Taraxacum (dandelion; Asteraceae) indicates a duplicated DIP-gene

PubMed Central

2010-01-01

Background DIPLOSPOROUS (DIP) is the locus for diplospory in Taraxacum, associated to unreduced female gamete formation in apomicts. Apomicts reproduce clonally through seeds, including apomeiosis, parthenogenesis, and autonomous or pseudogamous endosperm formation. In Taraxacum, diplospory results in first division restitution (FDR) nuclei, and inherits as a dominant, monogenic trait, independent from the other apomixis elements. A preliminary genetic linkage map indicated that the DIP-locus lacks suppression of recombination, which is unique among all other map-based cloning efforts of apomeiosis to date. FDR as well as apomixis as a whole are of interest in plant breeding, allowing for polyploidization and fixation of hybrid vigor, respectively. No dominant FDR or apomixis genes have yet been isolated. Here, we zoom-in to the DIP-locus by largely extending our initial mapping population, and by analyzing (local) suppression of recombination and allele sequence divergence (ASD). Results We identified 24 recombinants between two most closely linked molecular markers to DIP in an F1-population of 2227 plants that segregates for diplospory and lacks parthenogenesis. Both markers segregated c. 1:1 in the entire population, indicating a 1:1 segregation rate of diplospory. Fine-mapping showed three amplified fragment length polymorphisms (AFLPs) closest to DIP at 0.2 cM at one flank and a single AFLP at 0.4 cM at the other flank. Our data lacked strong evidence for ASD at marker regions close to DIP. An unexpected bias towards diplosporous plants among the recombinants (20 out of 24) was found. One third of these diplosporous recombinants showed incomplete penetrance of 50-85% diplospory. Conclusions Our data give interesting new insights into the structure of the diplospory locus in Taraxacum. We postulate a locus with a minimum of two DIP-genes and possibly including one or two enhancers or cis-regulatory elements on the basis of the bias towards diplosporous

Genetic fine-mapping of DIPLOSPOROUS in Taraxacum (dandelion; Asteraceae) indicates a duplicated DIP-gene.

PubMed

Vijverberg, Kitty; Milanovic-Ivanovic, Slavica; Bakx-Schotman, Tanja; van Dijk, Peter J

2010-07-26

DIPLOSPOROUS (DIP) is the locus for diplospory in Taraxacum, associated to unreduced female gamete formation in apomicts. Apomicts reproduce clonally through seeds, including apomeiosis, parthenogenesis, and autonomous or pseudogamous endosperm formation. In Taraxacum, diplospory results in first division restitution (FDR) nuclei, and inherits as a dominant, monogenic trait, independent from the other apomixis elements. A preliminary genetic linkage map indicated that the DIP-locus lacks suppression of recombination, which is unique among all other map-based cloning efforts of apomeiosis to date. FDR as well as apomixis as a whole are of interest in plant breeding, allowing for polyploidization and fixation of hybrid vigor, respectively. No dominant FDR or apomixis genes have yet been isolated. Here, we zoom-in to the DIP-locus by largely extending our initial mapping population, and by analyzing (local) suppression of recombination and allele sequence divergence (ASD). We identified 24 recombinants between two most closely linked molecular markers to DIP in an F1-population of 2227 plants that segregates for diplospory and lacks parthenogenesis. Both markers segregated c. 1:1 in the entire population, indicating a 1:1 segregation rate of diplospory. Fine-mapping showed three amplified fragment length polymorphisms (AFLPs) closest to DIP at 0.2 cM at one flank and a single AFLP at 0.4 cM at the other flank. Our data lacked strong evidence for ASD at marker regions close to DIP. An unexpected bias towards diplosporous plants among the recombinants (20 out of 24) was found. One third of these diplosporous recombinants showed incomplete penetrance of 50-85% diplospory. Our data give interesting new insights into the structure of the diplospory locus in Taraxacum. We postulate a locus with a minimum of two DIP-genes and possibly including one or two enhancers or cis-regulatory elements on the basis of the bias towards diplosporous recombinants and incomplete penetrance

ALLOY COATINGS AND METHOD OF APPLYING

DOEpatents

Eubank, L.D.; Boller, E.R.

1958-08-26

A method for providing uranium articles with a pro tective coating by a single dip coating process is presented. The uranium article is dipped into a molten zinc bath containing a small percentage of aluminum. The resultant product is a uranium article covered with a thin undercoat consisting of a uranium-aluminum alloy with a small amount of zinc, and an outer layer consisting of zinc and aluminum. The article may be used as is, or aluminum sheathing may then be bonded to the aluminum zinc outer layer.

Steeply-dipping extension fractures in the Newark basin, New Jersey

USGS Publications Warehouse

Herman, G.C.

2009-01-01

Late Triassic and Early Jurassic bedrock in the Newark basin is pervasively fractured as a result of Mesozoic rifting of the east-central North American continental margin. Tectonic rifting imparted systematic sets of steeply-dipping, en ??chelon, Mode I, extension fractures in basin strata including ordinary joints and veins. These fractures are arranged in transitional-tensional arrays resembling normal dip-slip shear zones. They contributed to crustal stretching, sagging, and eventual faulting of basin rift deposits. Extension fractures display progressive linkage and spatial clustering that probably controlled incipient fault growth. They cluster into three prominent strike groups correlated to early, intermediate, and late-stage tectonic events reflecting about 50- 60?? of counterclockwise rotation of incremental stretching directions. Finite strain analyses show that extension fractures allowed the stretching of basin strata by a few percent, and these fractures impart stratigraphic dips up to a few degrees in directions opposing fracture dips. Fracture groups display three-dimensional spatial variability but consistent geometric relations. Younger fractures locally cut across and terminate against older fractures having more complex vein-cement morphologies and bed-normal folds from stratigraphic compaction. A fourth, youngest group of extension fractures occur sporadically and strike about E-W in obliquely inverted crustal blocks. A geometric analysis of overlapping fracture sets shows how fracture groups result from incremental rotation of an extending tectonic plate, and that old fractures can reactivate with oblique slip components in the contemporary, compressive stress regime. ?? 2008 Elsevier Ltd. All rights reserved.

40 CFR 420.125 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

... product Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium (hexavalent) 1 0.000150 0.0000501 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge... product Lead 0.00451 0.00150 Zinc 0.00601 0.00200 Chromium (hexavalent) 1 0.000601 0.000200 1 The...

40 CFR 420.125 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... product Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium (hexavalent) 1 0.000150 0.0000501 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge... product Lead 0.00451 0.00150 Zinc 0.00601 0.00200 Chromium (hexavalent) 1 0.000601 0.000200 1 The...

40 CFR 420.125 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... product Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium (hexavalent) 1 0.000150 0.0000501 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge... product Lead 0.00451 0.00150 Zinc 0.00601 0.00200 Chromium (hexavalent) 1 0.000601 0.000200 1 The...

40 CFR 420.125 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... product Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium (hexavalent) 1 0.000150 0.0000501 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge... product Lead 0.00451 0.00150 Zinc 0.00601 0.00200 Chromium (hexavalent) 1 0.000601 0.000200 1 The...

Chromium and Ruthenium-Doped Zinc Oxide Thin Films for Propane Sensing Applications

PubMed Central

Gómez-Pozos, Heberto; González-Vidal, José Luis; Torres, Gonzalo Alberto; Rodríguez-Baez, Jorge; Maldonado, Arturo; de la Luz Olvera, María; Acosta, Dwight Roberto; Avendaño-Alejo, Maximino; Castañeda, Luis

2013-01-01

Chromium and ruthenium-doped zinc oxide (ZnO:Cr) and (ZnO:Ru) thin solid films were deposited on soda-lime glass substrates by the sol-gel dip-coating method. A 0.6 M solution of zinc acetate dihydrate dissolved in 2-methoxyethanol and monoethanolamine was used as basic solution. Chromium (III) acetylacetonate and Ruthenium (III) trichloride were used as doping sources. The Ru incorporation and its distribution profile into the films were proved by the SIMS technique. The morphology and structure of the films were studied by SEM microscopy and X-ray diffraction measurements, respectively. The SEM images show porous surfaces covered by small grains with different grain size, depending on the doping element, and the immersions number into the doping solutions. The sensing properties of ZnO:Cr and ZnO:Ru films in a propane (C3H8) atmosphere, as a function of the immersions number in the doping solution, have been studied in the present work. The highest sensitivity values were obtained for films doped from five immersions, 5.8 and 900, for ZnO:Cr and ZnO:Ru films, respectively. In order to evidence the catalytic effect of the chromium (Cr) and ruthenium (Ru), the sensing characteristics of undoped ZnO films are reported as well. PMID:23482091

Exposure to sheep dip and the incidence of acute symptoms in a group of Welsh sheep farmers.

PubMed Central

Rees, H

1996-01-01

OBJECTIVES: To measure the exposure of a group of farmers to organophosphate pesticide in sheep dip, and to record the incidence of symptoms after exposure. DESIGN: A prospective study of the autumn 1992 dipping period. Working methods were assessed by questionnaire. Absorption of organophosphate pesticide was estimated before, immediately after, and six weeks after dipping by measuring plasma cholinesterase, erythrocyte cholinesterase, and dialkylphosphate urinary metabolites of organophosphates. Symptoms were recorded by questionnaire at the same time as biological monitoring. Possible confounding factors were identified by medical examination of the subjects. SETTING: Three community council electoral wards in Powys, typical of hill sheep farming areas in Wales. SUBJECTS: All (38) men engaged in sheep dipping living in the three community council electoral wards. RESULTS: 23 sheep farmers and one dipping contractor completed the study--a response rate of 63%. A sample of seven men who refused to enter the full study had similar working practices to the 24 subjects. Subjects reported inadequate handling precautions, and significant skin contamination with dip. Two men reported under diluting dip concentrate for use. Both had significant depression of erythrocyte cholinesterase after dipping. This indicated some absorption of organophosphate pesticide--but this did not reach levels usually associated with toxicity. It was not clear whether the symptoms of these two mens were caused by organophosphate exposure. Measurement of dialkylphosphate urinary metabolites in a single specimen of urine voided shortly after the end of dipping could not be correlated with individual exposure. CONCLUSIONS: Sheep dipping is strenuous and dirty work and sheep farmers find it difficult to wear personal protective equipment and avoid skin contamination with dip. In this limited study, farmers did not seem to have significant organophosphate toxicity, despite using inadequate

dipIQ: Blind Image Quality Assessment by Learning-to-Rank Discriminable Image Pairs.

PubMed

Ma, Kede; Liu, Wentao; Liu, Tongliang; Wang, Zhou; Tao, Dacheng

2017-05-26

Objective assessment of image quality is fundamentally important in many image processing tasks. In this work, we focus on learning blind image quality assessment (BIQA) models which predict the quality of a digital image with no access to its original pristine-quality counterpart as reference. One of the biggest challenges in learning BIQA models is the conflict between the gigantic image space (which is in the dimension of the number of image pixels) and the extremely limited reliable ground truth data for training. Such data are typically collected via subjective testing, which is cumbersome, slow, and expensive. Here we first show that a vast amount of reliable training data in the form of quality-discriminable image pairs (DIP) can be obtained automatically at low cost by exploiting largescale databases with diverse image content. We then learn an opinion-unaware BIQA (OU-BIQA, meaning that no subjective opinions are used for training) model using RankNet, a pairwise learning-to-rank (L2R) algorithm, from millions of DIPs, each associated with a perceptual uncertainty level, leading to a DIP inferred quality (dipIQ) index. Extensive experiments on four benchmark IQA databases demonstrate that dipIQ outperforms state-of-the-art OU-BIQA models. The robustness of dipIQ is also significantly improved as confirmed by the group MAximum Differentiation (gMAD) competition method. Furthermore, we extend the proposed framework by learning models with ListNet (a listwise L2R algorithm) on quality-discriminable image lists (DIL). The resulting DIL Inferred Quality (dilIQ) index achieves an additional performance gain.

Transverse oscillations and stability of prominences in a magnetic field dip

NASA Astrophysics Data System (ADS)

Kolotkov, D. Y.; Nisticò, G.; Nakariakov, V. M.

2016-05-01

Aims: We developed an analytical model of the global transverse oscillations and mechanical stability of a quiescent prominence in the magnetised environment with a magnetic field dip that accounts for the mirror current effect. Methods: The model is based on the interaction of line currents through the Lorentz force. Within this concept the prominence is treated as a straight current-carrying wire, and the magnetic dip is provided by two photospheric current sources. Results: Properties of both vertical and horizontal oscillations are determined by the value of the prominence current, its density and height above the photosphere, and the parameters of the magnetic dip. The prominence can be stable in both horizontal and vertical directions simultaneously when the prominence current dominates in the system and its height is less than the half-distance between the photospheric sources.

Production of zinc pellets

DOEpatents

Cooper, J.F.

1996-11-26

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

Production of zinc pellets

DOEpatents

Cooper, John F.

1996-01-01

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

Zinc Signals and Immunity.

PubMed

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

Zinc Signals and Immunity

PubMed Central

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-01-01

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as “zinc waves”, and late homeostatic zinc signals regarding prolonged changes in intracellular zinc. PMID:29064429

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

PubMed

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications.

PubMed

Kogan, Samuel; Sood, Aditya; Garnick, Mark S

2017-04-01

Our understanding of the role of zinc in normal human physiology is constantly expanding, yet there are major gaps in our knowledge with regard to the function of zinc in wound healing. This review aims to provide the clinician with sufficient understanding of zinc biology and an up-to-date perspective on the role of zinc in wound healing. Zinc is an essential ion that is crucial for maintenance of normal physiology, and zinc deficiency has many manifestations ranging from delayed wound healing to immune dysfunction and impairment of multiple sensory systems. While consensus has been reached regarding the detrimental effects of zinc deficiency on wound healing, there is considerable discord in the literature on the optimal methods and true benefits of zinc supplementation.

Zinc

MedlinePlus

... Guidelines for Americans and the U.S. Department of Agriculture's MyPlate . Where can I find out more about ... on food sources of zinc: U.S. Department of Agriculture's (USDA’s) National Nutrient Database Nutrient List for zinc ( ...

Dip-Coating Fabrication of Solar Cells

NASA Technical Reports Server (NTRS)

Koepke, B.; Suave, D.

1982-01-01

Inexpensive silicon solar cells made by simple dip technique. Cooling shoes direct flow of helium on graphite-coated ceramic substrate to solidify film of liquid silicon on graphite surface as substrate is withdrawn from molten silicon. After heaters control cooling of film and substrate to prevent cracking. Gas jets exit at points about 10 mm from substrate surfaces and 6 to 10 mm above melt surface.

Measurement of adhesion properties between topcoat paint and metallized/galvanized steel with surface energy measurement equipment.

DOT National Transportation Integrated Search

2013-09-01

The objectives of this research project are: (1) Compare the adhesion properties of NEPCOAT-approved topcoat paint over : metallized or galvanized steel. Use surface-energy measuring technique to characterize the wetting properties of the liqui...

Blue light aids in coping with the post-lunch dip: an EEG study.

PubMed

Baek, Hongchae; Min, Byoung-Kyong

2015-01-01

The 'post-lunch dip' is a commonly experienced period of drowsiness in the afternoon hours. If this inevitable period can be disrupted by an environmental cue, the result will be enhanced workplace performance. Because blue light is known to be a critical cue for entraining biological rhythms, we investigated whether blue light illumination can be a practical strategy for coping with the post-lunch dip. Twenty healthy participants underwent a continuous performance test, during which the electroencephalogram (EEG) was recorded under four different illumination conditions: dark ( < 0.3 lx), 33% blue-enriched light, 66% blue-enriched light and white polychromatic light. As a result, exposure to blue-enriched light during the post-lunch dip period significantly reduced the EEG alpha activity, and increased task performance. Since desynchronisation of alpha activity reflects enhancement of vigilance, our findings imply that blue light might disrupt the post-lunch dip. Subsequent exploration of illumination parameters will be beneficial for possible chronobiological and ergonomic applications.

Discovery of Periodic Dips in the Brightest Hard X-Ray Source of M31 with EXTraS

NASA Astrophysics Data System (ADS)

Marelli, Martino; Tiengo, Andrea; De Luca, Andrea; Salvetti, David; Saronni, Luca; Sidoli, Lara; Paizis, Adamantia; Salvaterra, Ruben; Belfiore, Andrea; Israel, Gianluca; Haberl, Frank; D’Agostino, Daniele

2017-12-01

We performed a search for eclipsing and dipping sources in the archive of the EXTraS project—a systematic characterization of the temporal behavior of XMM-Newton point sources. We discovered dips in the X-ray light curve of 3XMM J004232.1+411314, which has been recently associated with the hard X-ray source dominating the emission of M31. A systematic analysis of XMM-Newton observations revealed 13 dips in 40 observations (total exposure time of ∼0.8 Ms). Among them, four observations show two dips, separated by ∼4.01 hr. Dip depths and durations are variable. The dips occur only during low-luminosity states ({L}0.2{--12}< 1× {10}38 erg s‑1), while the source reaches {L}0.2{--12}∼ 2.8× {10}38 erg s‑1. We propose that this system is a new dipping low-mass X-ray binary in M31 seen at high inclination (60°–80°) the observed dipping periodicity is the orbital period of the system. A blue HST source within the Chandra error circle is the most likely optical counterpart of the accretion disk. The high luminosity of the system makes it the most luminous (not ULX) dipper known to date.

Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

NASA Astrophysics Data System (ADS)

Pech-Canul, M. A.; Guía-Tello, J. C.; Pech-Canul, M. I.; Aguilar, J. C.; Gorocica-Díaz, J. A.; Arana-Guillén, R.; Puch-Bleis, J.

An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT) combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn)/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins.

Dip and anisotropy effects on flow using a vertically skewed model grid.

PubMed

Hoaglund, John R; Pollard, David

2003-01-01

Darcy flow equations relating vertical and bedding-parallel flow to vertical and bedding-parallel gradient components are derived for a skewed Cartesian grid in a vertical plane, correcting for structural dip given the principal hydraulic conductivities in bedding-parallel and bedding-orthogonal directions. Incorrect-minus-correct flow error results are presented for ranges of structural dip (0 < or = theta < or = 90) and gradient directions (0 < or = phi < or = 360). The equations can be coded into ground water models (e.g., MODFLOW) that can use a skewed Cartesian coordinate system to simulate flow in structural terrain with deformed bedding planes. Models modified with these equations will require input arrays of strike and dip, and a solver that can handle off-diagonal hydraulic conductivity terms.

Dipping Magnetic Reversal Boundaries at Endeavor Deep: Implications for Crustal Accretion

NASA Astrophysics Data System (ADS)

Pockalny, R. A.; Shields, A. C.; Larson, R. L.; Popham, C.

2005-12-01

Endeavor Deep, created by ongoing rifting along the northeastern boundary of the Juan Fernandez Microplate, provides a generous 75-km long view of the upper 1-3 km of oceanic crust created ~3 Ma at a fast-spreading ridge (~80 km/Myr, half-rate). Recent near-bottom surveys with the ROV Jason collected high-resolution video, rock samples, and 3-component magnetometer data along a 5 km-wide section of the southern wall of the deep. The video and rock samples define a crustal section with 300-500 m of primarily pillows and flows overlying a 400-500 m transition zone of extrusives and dykes. Forward modeling of the total magnetic intensity calculated from the 3-component magnetometer data identifies a magnetic polarity reversal that corresponds to a reversal boundary within magnetic anomaly 2a (C2An.2r - C2AN.3n , ~3.33 Ma). The location of the modeled polarity transition suggests the reversal boundary dips downward toward the original ridge axis with shallow dips (15 degrees) in the extrusive layer becoming increasingly steeper (25 degrees) in the deeper transition zone. The dipping character of the reversal boundary has also been observed along the walls of the Blanco Fracture Zone and is consistent with evolving crustal accretion models for seafloor created at intermediate- and fast-spreading rates, which predicts the rotation of the upper extrusive layer back toward the ridge axis. As a consequence of this rotation, originally horizontal flow boundaries will dip back toward the ridge axis and the magnitude of the dip will increase with depth into the crustal section. A small reversed magnetic polarity is also observed deeper within normally magnetized C2AN.3n chron, but with a very shallow dip (3-5 degrees). We doubt this is another normal-reverse-normal polarity transition, since the anomaly suspiciously coincides with the transition from dykes to extrusives. Therefore, we believe this anomaly is either the result of an edge-effect created by the different magnetic

EVALUATING THE POTENTIAL EFFICACY OF AN ANTIMICROBIAL-CONTAINING SEALANT ON DUCT LINER AND GALVANIZED STEEL

EPA Science Inventory

The article gives results of an evaluation of the potential efficacy of an antimicrobial-containing sealant on fibrous-glass duct liner (FGDL) and galvanized steel (GS) as used in heating, ventilating, and air-conditioning (HVAC) systems. HVAC systems become dirty to various degr...

Expectancy, False Galvanic Skin Response Feedback, and Systematic Desensitization in the Modification of Phobic Behavior

ERIC Educational Resources Information Center

Lick, John

1975-01-01

This study compared systematic desensitization and two pseudotherapy manipulations with and without false galvanic skin response feedback after every session suggesting improvement in the modification of intense snake and spider fear. The results indicated no consistent differences between the three treatment groups. (Author)

Hyperaccumulation of zinc by zinc-depleted Candida utilis grown in chemostat culture.

PubMed

Lawford, H G; Pik, J R; Lawford, G R; Williams, T; Kligerman, A

1980-01-01

The steady-state levels of zinc in Candida utilis yeast grown in continuous culture under conditions of zinc limitations are <1nmol Zn2+/mg dry weight of cells. Unlike carbon-limited cells, zinc-depleted cells from a zinc-limited chemostat possess the capacity to accumulate and store zinc at levels far in excess of the steady-state level of 4 nmol/mg dry biomass observed in carbon-limited chemostat cultures. Zinc uptake is energy-dependent and apparently undirectional since accumulated 65Zn neither exists from preloaded cells nor exchanges with cold Zn2+. The transport system exhibits a high affinity for Zn2+ (Km =.36micrM) with a Vmaxof 2.2 nmol per minute per milligram dry weight of cells. Growth during the period of the uptake assay is responsible for the apparent plateau level of 35 nmol Zn2+/mg dry weight of cells achieved after 20-30 min in the presence of 65Zn at pH 4.5 and 30 degrees C. Inhibition of growth during the uptake assay by cycloheximide results in a biphasic linear pattern of zinc accumulation where the cellular zinc is about 60 nmol/mg dry weight after 1 h. The enhanced level of accumulated zinc is not inhibtory to growth. Zinc-depleted C. utilis contains elevated amounts of polyphosphate and this anionic evidence does not allow discrimination between possible regulation of zinc homestasis either by inhibitions of zinc efflux through control of the membrane carrier or by control of the synthesis of a cytoplasmic zinc-sequestering macromolecule.

Design of multihundredwatt DIPS for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.; Geng, S. M.; Schreiber, J. G.; Withrow, C. A.; Schmitz, P. C.; Mccomas, Thomas J.

1991-01-01

Design of a dynamic isotope power system (DIPS) general purpose heat source (GPHS) and small free piston Stirling engine (FPSE) is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to SEI precursor missions. These are multihundredwatt missions. The incentive for any dynamic system is that it can save fuel which reduces cost and radiological hazard. However, unlike a conventional DIPS based on turbomachinery converions, the small Stirling DIPS can be advantageously scaled to multihundred watt unit size while preserving size and weight competitiveness with RTG's. Stirling conversion extends the range where dynamic systems are competitive to hundreds of watts (a power range not previously considered for dynamic systems). The challenge of course is to demonstrate reliability similar to RTG experience. Since the competative potential of FPSE as an isotope converter was first identified, work has focused on the feasibility of directly integrating GPHS with the Stirling heater head. Extensive thermal modeling of various radiatively coupled heat source/heater head geometries were performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within safe operating limits under all conditions including shutdown of one engine. Based on these results, preliminary characterizations of multihundred watt units were established.

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

ERIC Educational Resources Information Center

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…

Update on zinc biology.

PubMed

Solomons, Noel W

2013-01-01

Zinc has become a prominent nutrient of clinical and public health interest in the new millennium. Functions and actions for zinc emerge as increasingly ubiquitous in mammalian anatomy, physiology and metabolism. There is undoubtedly an underpinning in fundamental biology for all of the aspects of zinc in human health (clinical and epidemiological) in pediatric and public health practice. Unfortunately, basic science research may not have achieved a full understanding as yet. As a complement to the applied themes in the companion articles, a selection of recent advances in the domains homeostatic regulation and transport of zinc is presented; they are integrated, in turn, with findings on genetic expression, intracellular signaling, immunity and host defense, and bone growth. The elements include ionic zinc, zinc transporters, metallothioneins, zinc metalloenzymes and zinc finger proteins. In emerging basic research, we find some plausible mechanistic explanations for delayed linear growth with zinc deficiency and increased infectious disease resistance with zinc supplementation. Copyright © 2013 S. Karger AG, Basel.

Zinc at glutamatergic synapses.

PubMed

Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

2009-01-12

It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

Polyfibroblast: A Self-Healing and Galvanic Protection Additive

DTIC Science & Technology

2009-01-29

microencapsulated MCPU would have a limited shelf life. The shelf-life is expected to improve even further once the zinc outer shell is added and the microcapsules ...MEMBRANE 4 3.3 PREPARATION OF POLYURETHANE MICROCAPSULES 5 3.4 ELECTROLESS ZINC DEPOSITION 7 4 NEXT STEPS 4.1 ELECTROCHEMICAL ROUTE 7 4.2...Plating conditions must be adjusted to form thicker walls, however. We were also successful in microencapsulating uncured polyurethane resin in a hard

Metallurgical characterization, galvanic corrosion, and ionic release of orthodontic brackets coupled with Ni-Ti archwires.

PubMed

Darabara, Myrsini S; Bourithis, Lefteris I; Zinelis, Spiros; Papadimitriou, George D

2007-04-01

In orthodontics, a combination of metallic alloys is placed into the oral cavity during medical treatment and thus the corrosion resistance and ionic release of these appliances is of vital importance. The aim of this study is to investigate the elemental composition, microstructure, hardness, corrosion properties, and ionic release of commercially available orthodontic brackets and Copper Ni-Ti archwires. Following the assessment of the elemental composition of the orthodontic wire (Copper Ni-Ti) and the six different brackets (Micro Loc, Equilibrium, OptiMESH(XRT), Gemini, Orthos2, and Rematitan), cyclic polarization curves were obtained for each material to estimate the susceptibility of each alloy to pitting corrosion in 1M lactic acid. Galvanic corrosion between the orthodontic wire and each bracket took place in 1M lactic acid for 28 days at 37 degrees C and then the ionic concentration of Nickel and Chromium was studied. The orthodontic wire is made up from a Ni-Ti alloy with copper additions, while the orthodontic brackets are manufactured by different stainless steel grades or titanium alloys. All tested wires and brackets with the exception of Gemini are not susceptible to pitting corrosion. In galvanic corrosion, following exposure for 28 days, the lowest potential difference (approximately 250 mV) appears for the orthodontic wire Copper Ni-Ti and the bracket made up from pure titanium (Rematitan) or from the stainless steel AISI 316 grade (Micro Loc). Following completion of the galvanic corrosion experiments, measurable quantities of chromium and nickel ions were found in the residual lactic acid solution. (c) 2006 Wiley Periodicals, Inc.

Nanocrystal floating gate memory with solution-processed indium-zinc-tin-oxide channel and colloidal silver nanocrystals

NASA Astrophysics Data System (ADS)

Hu, Quanli; Ha, Sang-Hyub; Lee, Hyun Ho; Yoon, Tae-Sik

2011-12-01

A nanocrystal (NC) floating gate memory with solution-processed indium-zinc-tin-oxide (IZTO) channel and silver (Ag) NCs embedded in thin gate dielectric layer (SiO2(30 nm)/Al2O3(3 nm)) was fabricated. Both the IZTO channel and colloidal Ag NC layers were prepared by spin-coating and subsequent annealing, and dip-coating process, respectively. A threshold voltage shift up to ~0.9 V, corresponding to the electron density of 6.5 × 1011 cm-2, at gate pulsing <=10 V was achieved by the charging of high density NCs. These results present the successful non-volatile memory characteristics of an oxide-semiconductor transistor fabricated through solution processes.

29 CFR 1910.125 - Additional requirements for dipping and coating operations that use flammable or combustible...

Code of Federal Regulations, 2010 CFR

2010-07-01

... overflow piping is at least 3 inches (7.6 cm) in diameter and has sufficient capacity to prevent the dip... liquid to the tank is electrically bonded to the dip tank and positively grounded to prevent static... must prohibit smoking in a vapor area and must post a readily visible “No Smoking” sign near each dip...

Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

PubMed

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.

Synergistic influence of Al, Ni, Bi and Sn addition to a zinc bath upon growth kinetics and the structure of coatings

NASA Astrophysics Data System (ADS)

Kania, H.; Liberski, P.

2012-05-01

In this article the authors have analysed the current knowledge about the influence of alloy additions used in galvanizing baths. The optimum concentration of Al, Ni, Bi and Sn addition has been established. Some tests have been conducted to determine the synergistic effect of the addition of AlNiBiSn to a zinc bath upon the structure and growth kinetics of coatings. The structure of the coatings obtained on steel with low silicon contents and on Sandelin steel as well as their chemical composition have been revealed. It has been established that the addition of AlNiBiSn helps to reduce excessive growth of coating on Sandelin steel. The chemical composition and the structure of the coating on Sandelin steel are similar to the chemical composition and structure obtained on steel with regular silicon contents.

Zinc and Zinc Transporters: Novel Regulators of Ventricular Myocardial Development.

PubMed

Lin, Wen; Li, Deqiang

2018-06-01

Ventricular myocardial development is a well-orchestrated process involving different cardiac structures, multiple signal pathways, and myriad proteins. Dysregulation of this important developmental event can result in cardiomyopathies, such as left ventricle non-compaction, which affect the pediatric population and the adults. Human and mouse studies have shed light upon the etiology of some cardiomyopathy cases and highlighted the contribution of both genetic and environmental factors. However, the regulation of ventricular myocardial development remains incompletely understood. Zinc is an essential trace metal with structural, enzymatic, and signaling function. Perturbation of zinc homeostasis has resulted in developmental and physiological defects including cardiomyopathy. In this review, we summarize several mechanisms by which zinc and zinc transporters can impact the regulation of ventricular myocardial development. Based on our review, we propose that zinc deficiency and mutations of zinc transporters may underlie some cardiomyopathy cases especially those involving ventricular myocardial development defects.

Metastable Phases of Dross Particles Formed in a Molten Zinc Bath and Prediction of Soluble Aluminum During Galvannealing Processes

NASA Astrophysics Data System (ADS)

Paik, Doo-Jin; Hong, Moon-Hi; Huh, Yoon; Park, Joo Hyun; Chae, Hong-Kook; Park, Seok-Ho; Choun, Si-Youl

2012-06-01

The morphology, chemistry, and crystallographic characteristics of metastable dross particles were identified. These particles are formed during the initial stage of precipitation. The particles had aluminum concentrations of 15 to 80 mass pct, with values that decreased gradually as particle size increased. These metastable dross particles were a mixture of the crystalline phase of FeZn10, which is called the "delta phase," and the high-aluminum amorphous phase, which covered the surface of the crystalline phase. The new "meta Q" concept was proposed to predict the amount of soluble aluminum in the zinc bath by considering nucleation kinetics and particle growth. The results calculated using the "meta Q" concept were compared with the values measured by the aluminum sensor, which were taken during the same period at the commercial galvanizing line. The mean of the absolute values of the differences between the calculated and measured values was 9.7 ppm.

Isolation of a sulfide-producing bacterial consortium from cooling-tower water: Evaluation of corrosive effects on galvanized steel.

PubMed

Ilhan-Sungur, Esra; Ozuolmez, Derya; Çotuk, Ayşın; Cansever, Nurhan; Muyzer, Gerard

2017-02-01

Sulfidogenic Clostridia and sulfate reducing bacteria (SRB) often cohabit in nature. The presence of these microorganisms can cause microbially influenced corrosion (MIC) of materials in different ways. To investigate this aspect, bacteria were isolated from cooling tower water and used in corrosion tests of galvanized steel. The identity of the isolates was determined by comparative sequence analysis of PCR-amplified 16S rDNA gene fragments, separated by denaturing gradient gel electrophoresis (DGGE). This analysis showed that, in spite of the isolation process, colonies were not pure and consisted of a mixture of bacteria affiliated with Desulfosporosinus meridiei and Clostridium sp. To evaluate the corrosive effect, galvanized steel coupons were incubated with a mixed culture for 4, 8, 24, 72, 96, 168, 360 and 744 h, along with a control set in sterile culture medium only. The corrosion rate was determined by weight loss, and biofilm formation and corroded surfaces were observed by scanning electron microscopy (SEM). Although the sulfide-producing bacterial consortium led to a slight increase in the corrosion of galvanized steel coupons, when compared to the previous studies it can be said that Clostridium sp. can reduce the corrosive effect of the Desulfosporosinus sp. strain. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

ERIC Educational Resources Information Center

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…

40 CFR 420.124 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... Zinc 0.000376 0.000125 Chromium (hexavalent) 1 0.0000376 0.0000125 pH (2) (2) 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge wastewaters from the... product TSS 0.175 0.0751 O&G 0.0751 0.0250 Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium...

40 CFR 420.124 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... Zinc 0.000376 0.000125 Chromium (hexavalent) 1 0.0000376 0.0000125 pH (2) (2) 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge wastewaters from the... product TSS 0.175 0.0751 O&G 0.0751 0.0250 Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium...

40 CFR 420.124 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... Zinc 0.000376 0.000125 Chromium (hexavalent) 1 0.0000376 0.0000125 pH (2) (2) 1 The limitations for hexavalent chromium shall be applicable only to galvanizing operations which discharge wastewaters from the... product TSS 0.175 0.0751 O&G 0.0751 0.0250 Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium...

40 CFR 420.123 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... per 1,000 lb) of product Lead 0.00113 0.000376 Zinc 0.00150 0.000500 Chromium (hexavalent) 1 0.000150 0.0000501 1 The limitations for hexavalent chromium shall be applicable only to galvanizing...) of product Lead 0.00451 0.00150 Zinc 0.00601 0.00200 Chromium (hexavalent) 1 0.000601 0.000200 1 The...

The Association of Pediatric Obesity With Nocturnal Non-Dipping on 24-Hour Ambulatory Blood Pressure Monitoring.

PubMed

Macumber, Ian R; Weiss, Noel S; Halbach, Susan M; Hanevold, Coral D; Flynn, Joseph T

2016-05-01

Obesity has been linked with abnormal nocturnal dipping of blood pressure (BP) in adults, which in turn is associated with poor cardiovascular outcomes. There are few data regarding abnormal dipping status in the obese pediatric population. The goal of this study was to further describe the relationship between obesity and non-dipping status on ambulatory blood pressure monitor (ABPM) in children. We conducted a cross-sectional study using a database of patients aged 5-21 years who had undergone 24-hour ABPM at Seattle Children's Hospital from January 2008 through May 2014. Subjects were grouped by body mass index (BMI) into lean (BMI 15th-85th percentile) and obese (BMI >95th percentile) groups. Compared to lean subjects (n = 161), obese subjects (n = 247) had a prevalence ratio (PR) for non-dipping of 2.15, adjusted for race (95% confidence interval (CI) = 1.25-3.42). Increasing severity of obesity was not further associated with nocturnal non-dipping. Nocturnal non-dipping was not associated with left ventricular hypertrophy (PR = 1.01, 95% CI = 0.71-1.44). These results suggest that in children, just as in adults, obesity is related to a relatively decreased dipping in nocturnal BP. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Socioeconomic Status, Nocturnal Blood Pressure Dipping, and Psychosocial Factors: A Cross-Sectional Investigation in Mexican-American Women

PubMed Central

Gallo, Linda C.; Roesch, Scott C.; Mills, Paul J.; Barrett-Connor, Elizabeth; Talavera, Greg A.; Elder, John P.; Matthews, Karen A.

2013-01-01

Background Despite established links between reduced nocturnal blood pressure (BP) dipping and cardiovascular disease, BP dipping research in Hispanics is limited. Purpose This study investigated socioeconomic status (SES) as a predictor of BP dipping and the contributions of psychosocial factors to this relationship. Analyses were conducted for the overall sample and separately for higher and lower acculturated women. Methods Mexican-American women (N=291; 40–65 years) reported demographics and completed psychosocial assessments and 36-h ambulatory BP monitoring. Results Lower SES related to reduced BP dipping in the overall sample and in more US-acculturated women (r’s=.17–.30, p’s<.05), but not in less-acculturated women (r’s=.07, p’s>.10). An indirect effect model from SES to BP dipping via psychosocial resources/risk fits well across samples. Conclusions In Mexican-American women, the nature of SES gradients in BP dipping and the roles of psychosocial resources/risk differ by acculturation level. PMID:22777880

Ginga observations of dipping low mass X ray binaries

NASA Technical Reports Server (NTRS)

Smale, Alan P.; Mukai, Koji; Williams, O. Rees; Jones, Mark H.; Parmar, Arvind N.; Corbet, Robin H. D.

1989-01-01

Ginga observations of several low mass X ray binaries displaying pronounced dips of variable depth and duration in their X ray light curves are analyzed. The periodic occultation of the central X ray source by azimuthal accretion disk structure is considered. A series of spectra selected by intensity from the dip data from XB1916-053, are presented. The effects of a rapidly changing column density upon the spectral fitting results are modeled. EXO0748-676 was observed in March 1989 for three days. The source was found to be in a bright state with a 1 to 20 keV flux of 8.8 x 10 (exp -10) erg/sqcms. The data include two eclipses, observed with high time resolution.

Enhanced Lamb dip for absolute laser frequency stabilization

NASA Technical Reports Server (NTRS)

Siegman, A. E.; Byer, R. L.; Wang, S. C.

1972-01-01

Enhanced Lamb dip width is 5 MHz and total depth is 10 percent of peak power. Present configuration is useful as frequency standard in near infrared. Technique extends to other lasers, for which low pressure narrow linewidth gain tubes can be constructed.

Analysis of Tube Free Hydroforming using an Inverse Approach with FLD-based Adjustment of Process Parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Johnson, Kenneth I.; Khaleel, Mohammad A.

2003-04-01

This paper employs an inverse approach (IA) formulation for the analysis of tubes under free hydroforming conditions. The IA formulation is derived from that of Guo et al. established for flat sheet hydroforming analysis using constant strain triangular membrane elements. At first, an incremental analysis of free hydroforming for a hot-dip galvanized (HG/Z140) DP600 tube is performed using the finite element Marc code. The deformed geometry obtained at the last converged increment is then used as the final configuration in the inverse analysis. This comparative study allows us to assess the predicting capability of the inverse analysis. The results willmore » be compared with the experimental values determined by Asnafi and Skogsgardh. After that, a procedure based on a forming limit diagram (FLD) is proposed to adjust the process parameters such as the axial feed and internal pressure. Finally, the adjustment process is illustrated through a re-analysis of the same tube using the inverse approach« less

Wetting and Interfacial Reactivity of Zn-Coated Steel Products with Cu-Si, Cu-Sn and Al-Si Filler Metals for Laser Brazing Application

NASA Astrophysics Data System (ADS)

Koltsov, Alexey; Cretteur, Laurent

2018-03-01

The laser brazing process is successfully applied in automotive industry for joining of roofs and hatchbacks of vehicles. The bad wetting of the brazing alloy during the process can lead to the formation of random external porosities which are not allowed on visible parts. This paper describes the wettability and reactivity mechanisms at short contact time of Cu and Al matrix brazing alloys with different reactive elements (Si, Sn) on different steel products such as hot-dip galvanized steels, galvannealed steel and bare steel. Wetting experiments were carried out by the dispensed drop technique. The effects of alloying elements and brazing alloy matrix on interfacial reactivity are discussed. It was found that Cu matrix containing 3 wt.% Si is the most favorable for short time liquid/solid adhesion relatively to the other studied brazing alloy compositions. The brazing ability of different steel products is well correlated with the wettability and interfacial reactivity results.

Galvanic cathodic protection for reinforced concrete bridge decks: Field evaluation

NASA Astrophysics Data System (ADS)

Whiting, D.; Stark, D.

1981-06-01

The application of four sacrificial zinc anode cathodic protection systems to a reinforced concrete highway bridge deck is described. Two system designs were found to be the most promising in terms of polarized potentials and protective current densities achieved during the 3 year monitoring program. One design uses commercially available zinc ribbon anodes spaced at 5 in (127 mm) centers; the other, custom-fabricated perforated zinc sheets. Both systems are overlaid with an open-graded asphalt friction course. The systems yield maximum current density and polarized potentials under warm and moist environment conditions.

Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

PubMed Central

Maret, Wolfgang

2013-01-01

The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

Hot-compress: A new postdeposition treatment for ZnO-based flexible dye-sensitized solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haque Choudhury, Mohammad Shamimul, E-mail: shamimul129@gmail.com; Department of Electrical and Electronic Engineering, International Islamic University Chittagong, b154/a, College Road, Chittagong 4203; Kishi, Naoki

2016-08-15

Highlights: • A new postdeposition treatment named hot-compress is introduced. • Hot-compression gives homogeneous compact layer ZnO photoanode. • I-V and EIS analysis data confirms the efficacy of this method. • Charge transport resistance was reduced by the application of hot-compression. - Abstract: This article introduces a new postdeposition treatment named hot-compress for flexible zinc oxide–base dye-sensitized solar cells. This postdeposition treatment includes the application of compression pressure at an elevated temperature. The optimum compression pressure of 130 Ma at an optimum compression temperature of 70 °C heating gives better photovoltaic performance compared to the conventional cells. The aptness ofmore » this method was confirmed by investigating scanning electron microscopy image, X-ray diffraction, current-voltage and electrochemical impedance spectroscopy analysis of the prepared cells. Proper heating during compression lowers the charge transport resistance, longer the electron lifetime of the device. As a result, the overall power conversion efficiency of the device was improved about 45% compared to the conventional room temperature compressed cell.« less

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

PubMed

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P < 0.05) decrease in diet consumption, body weight and pituitary weight and decrease in gradation of intensity of zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

CFD study of ejector flow behavior in a blast furnace gas galvanizing plant

NASA Astrophysics Data System (ADS)

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.

Dipping-interface mapping using mode-separated Rayleigh waves

USGS Publications Warehouse

Luo, Y.; Xia, J.; Xu, Y.; Zeng, C.; Miller, R.D.; Liu, Q.

2009-01-01

Multichannel analysis of surface waves (MASW) method is a non-invasive geophysical technique that uses the dispersive characteristic of Rayleigh waves to estimate a vertical shear (S)-wave velocity profile. A pseudo-2D S-wave velocity section is constructed by aligning 1D S-wave velocity profiles at the midpoint of each receiver spread that are contoured using a spatial interpolation scheme. The horizontal resolution of the section is therefore most influenced by the receiver spread length and the source interval. Based on the assumption that a dipping-layer model can be regarded as stepped flat layers, high-resolution linear Radon transform (LRT) has been proposed to image Rayleigh-wave dispersive energy and separate modes of Rayleigh waves from a multichannel record. With the mode-separation technique, therefore, a dispersion curve that possesses satisfactory accuracy can be calculated using a pair of consecutive traces within a mode-separated shot gather. In this study, using synthetic models containing a dipping layer with a slope of 5, 10, 15, 20, or 30 degrees and a real-world example, we assess the ability of using high-resolution LRT to image and separate fundamental-mode Rayleigh waves from raw surface-wave data and accuracy of dispersion curves generated by a pair of consecutive traces within a mode-separated shot gather. Results of synthetic and real-world examples demonstrate that a dipping interface with a slope smaller than 15 degrees can be successfully mapped by separated fundamental waves using high-resolution LRT. ?? Birkh??user Verlag, Basel 2009.

Engineering functionality gradients by dip coating process in acceleration mode.

PubMed

Faustini, Marco; Ceratti, Davide R; Louis, Benjamin; Boudot, Mickael; Albouy, Pierre-Antoine; Boissière, Cédric; Grosso, David

2014-10-08

In this work, unique functional devices exhibiting controlled gradients of properties are fabricated by dip-coating process in acceleration mode. Through this new approach, thin films with "on-demand" thickness graded profiles at the submillimeter scale are prepared in an easy and versatile way, compatible for large-scale production. The technique is adapted to several relevant materials, including sol-gel dense and mesoporous metal oxides, block copolymers, metal-organic framework colloids, and commercial photoresists. In the first part of the Article, an investigation on the effect of the dip coating speed variation on the thickness profiles is reported together with the critical roles played by the evaporation rate and by the viscosity on the fluid draining-induced film formation. In the second part, dip-coating in acceleration mode is used to induce controlled variation of functionalities by playing on structural, chemical, or dimensional variations in nano- and microsystems. In order to demonstrate the full potentiality and versatility of the technique, original graded functional devices are made including optical interferometry mirrors with bidirectional gradients, one-dimensional photonic crystals with a stop-band gradient, graded microfluidic channels, and wetting gradient to induce droplet motion.

Modified corrosion protection coatings for Concrete tower of Transmission line

NASA Astrophysics Data System (ADS)

Guo, Kai; Jing, Xiangyang; Wang, Hongli; Yue, Zengwu; Wu, Yaping; Mi, Xuchun; Li, Xingeng; Chen, Suhong; Fan, Zhibin

2017-12-01

By adding nano SiO2 particles, an enhanced K-PRTV anti-pollution flashover coating had been prepared. Optical profile meter (GT-K), atomic force microscopy (AFM) and infrared spectrometer (FT-IR) characterization were carried out on the coating surface analysis. With the use of modified epoxy resin as the base material, the supplemented by phosphate as a corrosion stabilizer, to achieve a corrosion of steel and galvanized steel with rust coating. Paint with excellent adhesion, more than 10MPa (1), resistant to neutral salt spray 1000h does not appear rust point. At the same time coating a large amount of ultra-fine zinc powder can be added for the tower galvanized layer zinc repair function, while the paint in the zinc powder for the tower to provide sacrificial anode protection, to achieve self-repair function of the coating. Compared to the market with a significant reduction in the cost of rust paint, enhance the anti-corrosion properties.

HST spectroscopy of chemically peculiar hot subdwarfs: PG 0909+276 and UVO0512-08

NASA Astrophysics Data System (ADS)

Wild, James; Jeffery, Christopher Simon

2017-12-01

High-resolution ultraviolet spectroscopy of two chemically peculiar hot subdwarfs, PG 0909+276 and UVO0512-08, has been obtained using the Hubble Space Telescope. Chemical abundances in the stars' atmospheres were measured from previous optical spectra and from the new ultraviolet observations. Iron-group metals, including cobalt, copper and zinc, are highly enriched relative to typical subdwarf B (sdB) stars. Lead is also enriched, but with an abundance similar to other sdB stars. The surface chemistry of these two stars is quite distinct from both hydrogen-rich normal sdB stars and also from the intermediate helium-rich sdB stars which show heavy-element superabundances. A full explanation for exotic chemistries in hot subdwarfs remains elusive.

Contribution of Zinc Solubilizing Bacteria in Growth Promotion and Zinc Content of Wheat.

PubMed

Kamran, Sana; Shahid, Izzah; Baig, Deeba N; Rizwan, Muhammad; Malik, Kauser A; Mehnaz, Samina

2017-01-01

Zinc is an imperative micronutrient required for optimum plant growth. Zinc solubilizing bacteria are potential alternatives for zinc supplementation and convert applied inorganic zinc to available forms. This study was conducted to screen zinc solubilizing rhizobacteria isolated from wheat and sugarcane, and to analyze their effect on wheat growth and development. Fourteen exo-polysaccharides producing bacterial isolates of wheat were identified and characterized biochemically as well as on the basis of 16S rRNA gene sequences. Along these, 10 identified sugarcane isolates were also screened for zinc solubilizing ability on five different insoluble zinc sources. Out of 24, five strains, i.e., EPS 1 ( Pseudomonas fragi) , EPS 6 ( Pantoea dispersa) , EPS 13 ( Pantoea agglomerans) , PBS 2 ( E. cloacae) and LHRW1 ( Rhizobium sp.) were selected (based on their zinc solubilizing and PGP activities) for pot scale plant experiments. ZnCO 3 was used as zinc source and wheat seedlings were inoculated with these five strains, individually, to assess their effect on plant growth and development. The effect on plants was analyzed based on growth parameters and quantifying zinc content of shoot, root and grains using atomic absorption spectroscopy. Plant experiment was performed in two sets. For first set of plant experiments (harvested after 1 month), maximum shoot and root dry weights and shoot lengths were noted for the plants inoculated with Rhizobium sp. (LHRW1) while E. cloacae (PBS 2) increased both shoot and root lengths. Highest zinc content was found in shoots of E. cloacae (PBS 2) and in roots of P. agglomerans (EPS 13) followed by zinc supplemented control. For second set of plant experiment, when plants were harvested after three months, Pantoea dispersa (EPS 6), P. agglomerans (EPS 13) and E. cloacae (PBS 2) significantly increased shoot dry weights. However, significant increase in root dry weights and maximum zinc content was recorded for Pseudomonas fragi (EPS

Branched tellurium hollow nanofibers by galvanic displacement reaction and their sensing performance toward nitrogen dioxide.

PubMed

Park, Hosik; Jung, Hyunsung; Zhang, Miluo; Chang, Chong Hyun; Ndifor-Angwafor, N George; Choa, Yongho; Myung, Nosang V

2013-04-07

Electrospinning and galvanic displacement reaction were combined to synthesize ultra-long hollow tellurium (Te) nanofibers with controlled dimensions, morphology and crystallinity by simply tailoring the electrolyte concentration applied. Within different morphologies of nanofibers, the branched Te nanostructure shows the greatest sensing performance towards NO2 at room temperature.

Zinc

USDA-ARS?s Scientific Manuscript database

Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

CSI 2264: Simultaneous optical and X-ray variability in pre-main sequence stars. I. Time resolved X-ray spectral analysis during optical dips and accretion bursts in stars with disks

NASA Astrophysics Data System (ADS)

Guarcello, M. G.; Flaccomio, E.; Micela, G.; Argiroffi, C.; Sciortino, S.; Venuti, L.; Stauffer, J.; Rebull, L.; Cody, A. M.

2017-06-01

Context. Pre-main sequence stars are variable sources. The main mechanisms responsible for their variability are variable extinction, unsteady accretion, and rotational modulation of both hot and dark photospheric spots and X-ray-active regions. In stars with disks, this variability is related to the morphology of the inner circumstellar region (≤0.1 AU) and that of the photosphere and corona, all impossible to be spatially resolved with present-day techniques. This has been the main motivation for the Coordinated Synoptic Investigation of NGC 2264, a set of simultaneous observations of NGC 2264 with 15 different telescopes. Aims: In this paper, we focus on the stars with disks. We analyze the X-ray spectral properties extracted during optical bursts and dips in order to unveil the nature of these phenomena. Stars without disks are studied in a companion paper. Methods: We analyze simultaneous CoRoT and Chandra/ACIS-I observations to search for coherent optical and X-ray flux variability in stars with disks. Then, stars are analyzed in two different samples. In stars with variable extinction, we look for a simultaneous increase of optical extinction and X-ray absorption during the optical dips; in stars with accretion bursts, we search for soft X-ray emission and increasing X-ray absorption during the bursts. Results: We find evidence for coherent optical and X-ray flux variability among the stars with variable extinction. In 9 of the 24 stars with optical dips, we observe a simultaneous increase of X-ray absorption and optical extinction. In seven dips, it is possible to calculate the NH/AV ratio in order to infer the composition of the obscuring material. In 5 of the 20 stars with optical accretion bursts, we observe increasing soft X-ray emission during the bursts that we associate to the emission of accreting gas. It is not surprising that these properties are not observed in all the stars with dips and bursts, since favorable geometric configurations are

Zinc and Chlamydia trachomatis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugarman, B.; Epps, L.R.

1985-07-01

Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remainedmore » constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.« less

Electrochemical Behaviour and Galvanic Effects of Titanium Implants Coupled to Metallic Suprastructures in Artificial Saliva

PubMed Central

Mellado-Valero, Ana; Igual Muñoz, Anna; Guiñón Pina, Virginia

2018-01-01

The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys. PMID:29361767

Electrochemical Behaviour and Galvanic Effects of Titanium Implants Coupled to Metallic Suprastructures in Artificial Saliva.

PubMed

Mellado-Valero, Ana; Muñoz, Anna Igual; Pina, Virginia Guiñón; Sola-Ruiz, Ma Fernanda

2018-01-22

The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Tapas; Satpati, Biswarup, E-mail: biswarup.satpati@saha.ac.in; Kabiraj, D.

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.

Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

PubMed Central

Wilson, Rebecca L.; Grieger, Jessica A.; Bianco-Miotto, Tina; Roberts, Claire T.

2016-01-01

Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status. PMID:27754451

The role of parents, friends and teachers in adolescents' cigarette smoking and tombak dipping in Sudan.

PubMed

El-Amin, Salma El-Tayeb; Nwaru, Bright I; Ginawi, Ibrahim; Pisani, Paola; Hakama, Matti

2011-03-01

To assess the influence of smoking and tombak (local smokeless tobacco) dipping by parents, teachers and friends on cigarette smoking and tombak dipping by school-going Sudanese adolescents. This was a school-based cross-sectional survey was conducted in 2005-2006. Logistic regression was used for the analysis. A total of 4277 Sudanese school-going adolescents (aged 11-17 years) from 23 schools who completed an anonymous self-administered questionnaire on the use of tobacco products. Main outcome measures were self-reported tobacco use during the previous month defined current tobacco use. Ever smoking, tombak dipping and other tobacco products were also considered as outcomes. After adjusting for sex, age and school grade, adolescents' smoking habits were strongly associated with the habit in their parents and friends and, more weakly, with tombak dipping by teachers. When adjusted for each other, the association with smoking in friends was unaffected and remained significant (prevalence OR (POR) of having ever smoked was 1.94, 95% CI 1.64 to 2.29; OR of being current smoker was 3.77, 95% CI 2.80 to 5.07). Tobacco smoking in friends was positively associated with adolescents ever tombak dipping (POR 1.81, 95% CI 1.41 to 2.33) and current dipping (OR 3.33, 95% CI 2.20 to 5.05). The association with parental habits was reduced but still significantly elevated. Tombak dipping by teachers was only associated with adolescents ever tobacco smoking. Tobacco use by parents, teachers and friends was associated with adolescents' tobacco habits. The influence of friends was the strongest. In developing programmes against adolescents' tobacco habits, there is need to target the influence of these 'significant others'. Sudan needs to develop and implement comprehensive anti-smoking and anti-tombak dipping legislation to reduce the growing prevalence of such habits.

A comparative study on the effects of glucose monohydrate, hot water, and sodium pyrophosphate on quality parameters and microbial flora of deboned and matured brisket.

PubMed

Gögüs, U; Bozoglu, F; Alpas, H

2007-09-01

Organic acids, hot water (HW), and chlorine have been commonly used in carcass decontamination for years. However, it has been observed that organic acids have adverse effects on color and are corrosive, while HW is discoloring. On the other hand, glucose fermentation by lactic acid bacteria in meat during the rigor period might be effective in microbial inhibition, without producing an adverse effect on the organoleptic quality of meat. Therefore, this study has aimed at finding an alternative meat decontamination procedure without any adverse effects. In this study, briskets were treated with 6 different applications: D (+) glucose monohydrate (GM) (16.51 g/100 mL, 15%) dip, HW dip, sodium pyrophosphate (SPP) and HW dip, GM + SPP + HW, and GM + HW combined dip. Then, the results of these applications were compared. First, GM + HW and GM + SPP + HW applications indicated more inhibition on Pseudomonas spp., Coliform and total Mesophile Aerob Bacteria growth, resulting in lower acidity loss (P < 0.01). Second, additional use of SPP with GM and HW did not enhance microbial inhibition (P < 0.01). Finally and most importantly, GM, 15%, improved a and b Hunter values significantly (P < 0.01), producing a very intense red meat color that can be very attractive for meat producers and consumers.

Chandra observation of the dipping source XB 1254-690

NASA Astrophysics Data System (ADS)

Iaria, R.; di Salvo, T.; Lavagetto, G.; D'Aí, A.; Robba, N. R.

2007-03-01

We present the results of a 53 ks long Chandra observation of the dipping source XB 1254-690. During the observation neither bursts or dips were observed. From the zero-order image we estimated the precise X-ray coordinates of the source with a 90% uncertainty of 0.6´´. Since the lightcurve did not show any significant variability, we extracted the spectrum corresponding to the whole observation. We confirmed the presence of the Fe XXVI Kα absorption lines with a larger accuracy with respect to the previous XMM EPIC pn observation. Assuming that the line width were due to a bulk motion or a turbulence associated to the coronal activity, we estimate that the lines were produced in a photoionized absorber between the coronal radius and the outer edge of the accretion disk.

Stainless and Galvanized Steel, Hydrophobic Admixture and Flexible Polymer-Cement Coating Compared in Increasing Durability of Reinforced Concrete Structures

NASA Astrophysics Data System (ADS)

Tittarelli, Francesca; Giosuè, Chiara; Mobili, Alessandra

2017-08-01

The use of stainless or galvanized steel reinforcements, a hydrophobic admixture or a flexible polymer-cement coating were compared as methods to improve the corrosion resistance of sound or cracked reinforced concrete specimens exposed to chloride rich solutions. The results show that in full immersion condition, negligible corrosion rates were detected in all cracked specimens, except those treated with the flexible polymer-cement mortar as preventive method against corrosion and the hydrophobic concrete specimens. High corrosion rates were measured in all cracked specimens exposed to wet-dry cycles, except for those reinforced with stainless steel, those treated with the flexible polymer-cement coating as restorative method against reinforcement corrosion and for hydrophobic concrete specimens reinforced with galvanized steel reinforcements.

Dietary sodium and nocturnal blood pressure dipping in normotensive men and women.

PubMed

Brian, M S; Dalpiaz, A; Matthews, E L; Lennon-Edwards, S; Edwards, D G; Farquhar, W B

2017-02-01

Impaired nocturnal blood pressure (BP) dipping (i.e., <10% decline in nocturnal BP) is associated with an increased risk of cerebrovascular and cardiovascular diseases. Excess sodium has been shown to impair BP regulation and increase cardiovascular disease risk, yet few studies have assessed the influence of dietary sodium on nocturnal dipping in normotensive adults. The purpose of this study was to determine the effects of dietary sodium on BP dipping in normotensive men and women. Eighty healthy normotensive adults participated in a controlled feeding study (men: n=39, 34±2 years; women: n=41, 41±2 years). Participants consumed a standardized run-in 100 mmol sodium per day diet for 7 days, followed by 7 days of low-sodium (LS; 20 mmol per day) and high-sodium (HS; 300 mmol per day) diets in random order. On the final day of each diet, subjects wore a 24 h ambulatory BP monitor, collected a 24 h urine sample and provided a blood sample. During the run-in diet, 24 h urinary sodium excretion was 79.4±5.1 mmol per 24 h in men and 85.3±5.5 mmol per 24 h in women (P>0.05). Systolic BP dipping was not different between men (11.4±1.0%) and women (11.2±0.9%); (P>0.05). During the HS diet, 24 h urinary sodium excretion increased compared with the LS diet in men (LS=31.7±4.6 mmol per 24 h vs HS=235.0±13.9 mmol per 24 h, P<0.01) and women (LS=25.8±2.2 mmol per 24 h vs HS=234.7±13.8 mmol per 24 h, P<0.01). Despite this large increase in sodium intake and excretion, systolic BP dipping was not blunted in men (LS=8.9±1.0% vs HS=9.4±1.2%, P>0.05) or women (LS=10.3±0.8% vs HS=10.5±0.8%, P>0.05). Among normotensive men and women, HS does not blunt nocturnal BP dipping.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

PubMed

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

Electric and magnetic galvanic distortion decomposition of tensor CSAMT data. Application to data from the Buchans Mine (Newfoundland, Canada)

NASA Astrophysics Data System (ADS)

Garcia, Xavier; Boerner, David; Pedersen, Laust B.

2003-09-01

We have developed a Marquardt-Levenberg inversion algorithm incorporating the effects of near-surface galvanic distortion into the electromagnetic (EM) response of a layered earth model. Different tests on synthetic model responses suggest that for the grounded source method, the magnetic distortion does not vanish for low frequencies. Including this effect is important, although to date it has been neglected. We have inverted 10 stations of controlled-source audio-magnetotellurics (CSAMT) data recorded near the Buchans Mine, Newfoundland, Canada. The Buchans Mine was one of the richest massive sulphide deposits in the world, and is situated in a highly resistive volcanogenic environment, substantially modified by thrust faulting. Preliminary work in the area demonstrated that the EM fields observed at adjacent stations show large differences due to the existence of mineralized fracture zones and variable overburden thickness. Our inversion results suggest a three-layered model that is appropriate for the Buchans Mine. The resistivity model correlates with the seismic reflection interpretation that documents the existence of two thrust packages. The distortion parameters obtained from the inversion concur with the synthetic studies that galvanic magnetic distortion is required to interpret the Buchans data since the magnetic component of the galvanic distortion does not vanish at low frequency.

Functional studies of Drosophila zinc transporters reveal the mechanism for dietary zinc absorption and regulation

PubMed Central

2013-01-01

Background Zinc is key to the function of many proteins, but the process of dietary zinc absorption is not well clarified. Current knowledge about dietary zinc absorption is fragmented, and mostly derives from incomplete mammalian studies. To gain a comprehensive picture of this process, we systematically characterized all zinc transporters (that is, the Zip and ZnT family members) for their possible roles in dietary zinc absorption in a genetically amenable model organism, Drosophila melanogaster. Results A set of plasma membrane-resident zinc transporters was identified to be responsible for absorbing zinc from the lumen into the enterocyte and the subsequent exit of zinc to the circulation. dZip1 and dZip2, two functionally overlapping zinc importers, are responsible for absorbing zinc from the lumen into the enterocyte. Exit of zinc to the circulation is mediated through another two functionally overlapping zinc exporters, dZnT1, and its homolog CG5130 (dZnT77C). Somewhat surprisingly, it appears that the array of intracellular ZnT proteins, including the Golgi-resident dZnT7, is not directly involved in dietary zinc absorption. By modulating zinc status in different parts of the body, we found that regulation of dietary zinc absorption, in contrast to that of iron, is unresponsive to bodily needs or zinc status outside the gut. The zinc transporters that are involved in dietary zinc absorption, including the importers dZip1 and dZip2, and the exporter dZnT1, are respectively regulated at the RNA and protein levels by zinc in the enterocyte. Conclusions Our study using the model organism Drosophila thus starts to reveal a comprehensive sketch of dietary zinc absorption and its regulatory control, a process that is still incompletely understood in mammalian organisms. The knowledge gained will act as a reference for future mammalian studies, and also enable an appreciation of this important process from an evolutionary perspective. PMID:24063361

Cadmium Alternatives High Strength Steel JTP

DTIC Science & Technology

2005-03-01

Cadmium Alternatives HSS JTP Alternative Coatings Selected by JCAT: Primary Repair LHE Cadmium (control) IVD Aluminum (control) Zinc-Nickel, acid...Tin-Zinc Cadmium Alternatives HSS JTP Demonstration Tests Selected by JCAT: Phase I Phase II Hydrogen Embrittlement Hydrogen Re-Embrittlement (NRB...immersion, exposed C-ring (Army)) Bend Adhesion (Q/A) Appearance Throwing Power Composition Uniformity Strippability Galvanic Potential Bend Adhesion

Synthesis of Hollow Gold-Silver Alloyed Nanoparticles: A "Galvanic Replacement" Experiment for Chemistry and Engineering Students

ERIC Educational Resources Information Center

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…

Viscous dipping, application to the capture of fluids in living organisms

NASA Astrophysics Data System (ADS)

Lechantre, Amandine; Michez, Denis; Damman, Pascal

Some insects, birds and mammals use flower nectar as their energy resources. For this purpose, they developed specific skills to ingest viscous fluids. Depending on the sugar content, i.e., the viscosity, different strategies are observed in vivo. Indeed, butterflies use simple suction for low viscosity nectars; hummingbirds have a tongue made from two thin flexible sheets that bend to form a tube when immersed in a fluid; other animals exhibit in contrast complex papillary structures. We focus on this last method generally used for very viscous nectars. More specifically, bees and bats possess a tongue decorated with microstructures that, according to biologists, would be optimized for fluid capture by viscous dipping. In this talk, we will discuss this assumption by comparing physical models of viscous dipping to in vivo measurements. To mimic the tongue morphology, we used various rod shapes obtained by 3D printing. The influence of the type and size of lateral microstructures was then investigated and used to build a global framework describing viscous dipping for structured rods/tongues.

Saccule contribution to immediate early gene induction in the gerbil brainstem with posterior canal galvanic or hypergravity stimulation

NASA Technical Reports Server (NTRS)

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.

Charging system with galvanic isolation and multiple operating modes

DOEpatents

Kajouke, Lateef A.; Perisic, Milun; Ransom, Ray M.

2013-01-08

Systems and methods are provided for operating a charging system with galvanic isolation adapted for multiple operating modes. A vehicle charging system comprises a DC interface, an AC interface, a first conversion module coupled to the DC interface, and a second conversion module coupled to the AC interface. An isolation module is coupled between the first conversion module and the second conversion module. The isolation module comprises a transformer and a switching element coupled between the transformer and the second conversion module. The transformer and the switching element are cooperatively configured for a plurality of operating modes, wherein each operating mode of the plurality of operating modes corresponds to a respective turns ratio of the transformer.

Liquid Galvanic Coatings for Protection of Imbedded Metals

NASA Technical Reports Server (NTRS)

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.

Floral-Dip Transformation of Flax (Linum usitatissimum) to Generate Transgenic Progenies with a High Transformation Rate

PubMed Central

Bastaki, Nasmah K.; Cullis, Christopher A.

2014-01-01

Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation. PMID:25549243

Floral-dip transformation of flax (Linum usitatissimum) to generate transgenic progenies with a high transformation rate.

PubMed

Bastaki, Nasmah K; Cullis, Christopher A

2014-12-19

Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation.

Psychopathology and Incest: A DIPS Code Type Assessment.

ERIC Educational Resources Information Center

Gregory-Bills, Therese; Vincent, Ken

The Diagnostic Inventory of Personality and Symptoms (DIPS) was used to examine psychopathology in 30 therapy outpatients with histories of incest. Subjects also responded to the Beck Depression Inventory (BDI). Correlations were used to examine characteristics of the sample and to identify circumstances of their experiences of incest which…

Multistory duplexes with forward dipping roofs, north central Brooks Range, Alaska

USGS Publications Warehouse

Wallace, W.K.; Moore, Thomas E.; Plafker, G.

1997-01-01

The Endicott Mountains allochthon has been thrust far northward over the North Slope parautochthon in the northern Brooks Range. Progressively younger units are exposed northward within the allochthon. To the south, the incompetent Hunt Fork Shale has thickened internally by asymmetric folds and thrust faults. Northward, the competent Kanayut Conglomerate forms a duplex between a floor thrust in Hunt Fork and a roof thrust in the Kayak Shale. To the north, the competent Lisburne Group forms a duplex between a floor thrust in Kayak and a roof thrust in the Siksikpuk Formation. Both duplexes formed from north vergent detachment folds whose steep limbs were later truncated by south dipping thrust faults that only locally breach immediately overlying roof thrusts. Within the parautochthon, the Kayak, Lisburne, and Siksikpuk-equivalent Echooka Formation form a duplex identical to that in the allochthon. This duplex is succeeded abruptly northward by detachment folds in Lisburne. These folds are parasitic to an anticlinorium interpreted to reflect a fault-bend folded horse in North Slope "basement," with a roof thrust in Kayak and a floor thrust at depth. These structures constitute two northward tapered, internally deformed wedges that are juxtaposed at the base of the allochthon. Within each wedge, competent units have been shortened independently between detachments, located mainly in incompetent units. The basal detachment of each wedge cuts upsection forward (northward) to define a wedge geometry within which units dip regionally forward. These dips reflect forward decrease in internal structural thickening by forward vergent folds and hindward dipping thrust faults. Copyright 1997 by the American Geophysical Union.

Boron Abundances Across the "Li-Be Dip" in the Hyades Cluster

NASA Astrophysics Data System (ADS)

Boesgaard, Ann Merchant; Lum, Michael G.; Deliyannis, Constantine P.; King, Jeremy R.; Pinsonneault, Marc H.

2015-08-01

Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard and Tripicco in 1986. Using high-resolution, high signal-to-noise spectra from the Keck 10-m telescope, Boesgaard and King discovered the corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the Hyades. With the Space Telescope Imaging Spectrograph on HST we investigate B abundances in the Hyades F stars to look for a potential B dip. We use the resonance line of B I at 2497 A. These three elements are destroyed inside stars at increasingly hotter temperatures: 2.5 x 10$^6$, 3.5 x 10$^6$, and 5 x 10$^6$ K for Li, Be, B respectively. Consequently, these elements survive to increasingly greater depths in a star and their surface abundances act as a report on the depth and thoroughness of mixing in the star. We have used updated photometry from Hipparcos to find stellar parameters for the Hyades stars and have redetermined Li abundances (or upper limits) for 79 Hyades dwarfs, Be for 34 stars, and B in five stars. We find evidence for a small dip in the B abundance across the Li-Be dip. We have compared our nLTE B abundances for the three high B stars on either side of the Li-Be dip with those found by Duncan for the Hyades giants. This confirms the factor of ten decline in the B abundance in the Hyades giants as predicted by dilution due to the deepening of the surface convection zone.

Zinc triggers microglial activation.

PubMed

Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

2008-05-28

Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

Effect of 1,2,4-triazole on galvanic corrosion between cobalt and copper in CMP based alkaline slurry

NASA Astrophysics Data System (ADS)

Fu, Lei; Liu, Yuling; Wang, Chenwei; Han, Linan

2018-04-01

Cobalt has become a new type of barrier material with its unique advantages since the copper-interconnects in the great-large scale integrated circuits (GLSI) into 10 nm and below technical nodes, but cobalt and copper have severe galvanic corrosion during chemical–mechanical flattening. The effect of 1,2,4-triazole on Co/Cu galvanic corrosion in alkaline slurry and the control of rate selectivity of copper and cobalt were investigated in this work. The results of electrochemical experiments and polishing experiments had indicated that a certain concentration of 1,2,4-triazole could form a layer of insoluble and dense passive film on the surface of cobalt and copper, which reduced the corrosion potential difference between cobalt and copper. Meantime, the removal rate of cobalt and copper could be effectively controlled according to demand during the CMP process. When the study optimized slurry was composed of 0.5 wt% colloidal silica, 0.1 %vol. hydrogen peroxide, 0.05 wt% FA/O, 345 ppm 1,2,4-triazole, cobalt had higher corrosion potential than copper and the galvanic corrosion could be reduced effectively when the corrosion potential difference between them decreased to 1 mV and the galvanic corrosion current density reached 0.02 nA/cm2. Meanwhile, the removal rate of Co was 62.396 nm/min, the removal rate of Cu was 47.328 nm/min, so that the removal rate ratio of cobalt and copper was 1.32 : 1, which was a good amendment to the dishing pits. The contact potential corrosion of Co/Cu was very weak, which could be better for meeting the requirements of the barrier CMP. Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Natural Science Foundation of Hebei Province, China (No. F2015202267), and the Outstanding Young Science and Technology Innovation Fund of Hebei University of Technology (No. 2015007).

Evaluation of effect of galvanic corrosion between nickel-chromium metal and titanium on ion release and cell toxicity

PubMed Central

Choi, Jung-Yun

2015-01-01

PURPOSE The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens (10×10×1.5 mm) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing

Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

PubMed

Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

2018-03-01

The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

Clay and DOPA containing polyelectrolyte multilayer film for imparting anticorrosion properties to galvanized steel.

PubMed

Faure, Emilie; Halusiak, Emilie; Farina, Fabrice; Giamblanco, Nicoletta; Motte, Cécile; Poelman, Mireille; Archambeau, Catherine; Van de Weerdt, Cécile; Martial, Joseph; Jérôme, Christine; Duwez, Anne-Sophie; Detrembleur, Christophe

2012-02-07

A facile and green approach is developed to impart remarkable protection against corrosion to galvanized steel. A protecting multilayer film is formed by alternating the deposition of a polycation bearing catechol groups, used as corrosion inhibitors, with clay that induces barrier properties. This coating does not affect the esthetical aspect of the surface and does not release any toxic molecules in the environment.

The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

PubMed Central

Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

2015-01-01

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

Zinc Information

MedlinePlus

... for Eye Conditions Clinical Digest: Hepatitis C and Dietary Supplements Related Resources From Other Agencies Age-Related Eye Disease Study 2 (AREDS2) ( NEI ) Can Zinc Be Harmful? ( ODS ) Zinc ( ODS ) Follow NCCIH: Read our disclaimer ...

Zinc starvation induces autophagy in yeast

PubMed Central

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-01-01

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. PMID:28264932

A dipping, thick Farallon slab below central United States

NASA Astrophysics Data System (ADS)

Sun, D.; Gurnis, M.; Saleeby, J.; Helmberger, D. V.

2015-12-01

It has been hypothesized that much of the Laramide orogeny was caused by dynamic effects induced by an extensive flat slab during a period of plateau subduction. A particularly thick block containing the Shatsky Rise conjugate, now in the mid-mantle, left a distinctive deformation footprint from southern California to Denver, Colorado. Thus mid-mantle, relic slabs can provide fundamental information about past subduction and the history of plate tectonics if properly imaged. Here we find clear evidence for a northeastward dipping (35° dip), slab-like, but fat (up to 400-500 km thick) seismic anomaly within the top of the lower mantle below the central United States. Using a deep focus earthquake below Spain with direct seismic paths that propagate along the top and bottom of the anomaly, we find that the observed, stacked seismic waveforms recorded with the dense USArray show multi-pathing indicative of sharp top and bottom surfaces. Plate tectonic reconstructions in which the slab is migrated back in time suggest strong coupling of the slab to North America. In combination with the reconstructions, we interpret the structure as arising from eastward dipping Farallon subduction at the western margin of North America during the Cretaceous, in contrast with recent interpretations. The slab could have been fattened through a combination of pure shear thickening during flat-slab subduction and a folding instability during penetration into the lower mantle.

Electrochromic TiO2 Thin Film Prepared by Dip-Coating Technique

NASA Astrophysics Data System (ADS)

Suriani, S.; Kamisah, M. M.

2002-12-01

Titanium dioxide (TiO2) thin films were prepared by using sol-gel dip coating technique. The coating solutions were prepared by reacting titanium isopropoxide as precursors and ethanol as solvent. The films were formed on transparent ITO-coated glass by a dip coating technique and final dried at various temperatures up to 600 °C for 30 minutes. The films were characterized with the UV-Vis-NIR Spectrometer, Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). XRD results show that the films dried at 600 °C form anatase structure. From the spectroscopic studies, the sample shows electrochromic property.

The addition of a plain or herb-flavored reduced-fat dip is associated with improved preschoolers' intake of vegetables.

PubMed

Savage, Jennifer S; Peterson, Julie; Marini, Michele; Bordi, Peter L; Birch, Leann L

2013-08-01

This quasiexperimental study used a within-subjects experimental design to determine whether adding herbs and/or spices to a reduced-fat dip increased children's willingness to taste, liking of, and consumption of vegetables. Participants were preschool children aged 3 to 5 years who attended a child-care center in Central Pennsylvania in late 2008 and early 2009. First, children's familiarity with and liking of six raw vegetables and five dips (reduced-fat plain, herb, garlic, pizza, and ranch) were assessed. In Experiment 1 (n=34), children tasted a vegetable they liked, one they disliked, and one they refused, with a reduced-fat plain dip and their favorite reduced-fat herb-flavored dip. In Experiment 2 (n=26 or n=27), they rated their liking of celery and yellow squash, with and without their favorite reduced-fat herb dip (pizza or ranch), and their intake of those vegetable snacks was measured. In Experiment 1, the herb-flavored dip was preferred over the plain dip (P<0.01), and children were three times more likely to reject the vegetable alone, compared with eating the vegetable paired with an herb dip (P<0.001). In Experiment 2, children ate significantly more of a previously rejected or disliked vegetable (celery and squash) when offered with a preferred reduced-fat herb dip than when the vegetable was served alone (P<0.05). These findings suggest that offering vegetables with reduced-fat dips containing familiar herb and spice flavors can increase tasting and thereby promote liking, acceptance, and consumption of vegetables, including vegetables previously rejected or disliked. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Galvanic corrosion behaviour of HE 20 / MDN 138 & HE 20 / MDN 250 alloys in natural seawater

NASA Astrophysics Data System (ADS)

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.

Reconnaissance geologic study of the Vazante zinc district, Minas Gerais, Brazil

USGS Publications Warehouse

Thorman, Charles H.; Nahass, Samir

1977-01-01

The Vazante district, Minas Gerais, 130 km south of Paracatu, produces nearly all of Brazil's zinc metal. The district is situated on the western side of the Late Precambrian Bambul basin and along the eastern and leading edge of the north-trending Brazilian orogenic belt (ca. 600-500 m.y. old) that borders the western margin of the basin. Reconnaissance study indicates that bedding and low-angle thrust faulting, folding, and low-grade metamorphism dominated the structural development of the district. The structural trend within the district is northeasterly, and dips 20?-45 ? NW. Three sets of folds developed during the main period of eastward thrusting of older Precambrian rocks over the western margin of the Bambui basin. A fourth fold set is transverse to the regional trend. The rocks in the district are tentatively assigned to the Paraopeba Formation of the Bambui Group and are designated A through C in ascending order. Unit A is phyllite to phyllitic siltstone. Unit B consists of interbedded dolomitic limestone and marl-limestone. Irregularly distributed limestone ledges 20 to 100 m thick have the appearance of boudins. Their origin is attributed to a combination of rapid lateral facies changes and differential movement at different structural levels along bedding and low-angle thrust faults, with the formation of tear faults vertically limited by the thrust faults. Unit C consists of interbedded siltstone, dolomitic limestone, and sandstone. Phyllitic rocks along member interfaces in units B and C and at the base of unit C indicate differential penetrative deformation and bedding faulting. The contacts between units A, B, and C are interpreted to be low-angle or bedding faults, and their original stratigraphic positions with respect to each other is unknown. Zinc silicate minerals (hemimorphite and willemite) occur in a folded breccia zone in the lower part of unit B. The breccia zone is interpreted to be tectonic in origin, having formed along the step of a

Studies on the bioavailability of zinc in humans: intestinal interaction of tin and zinc.

PubMed

Solomons, N W; Marchini, J S; Duarte-Favaro, R M; Vannuchi, H; Dutra de Oliveira, J E