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Articles 151 - 180 of 248

Full-Text Articles in Chemical Engineering

Mathematical Modeling Of A Nickel-Cadmium Cell: Proton Diffusion In The Nickel Electrode, Pauline De Vidts, Ralph E. White Jan 1995

Mathematical Modeling Of A Nickel-Cadmium Cell: Proton Diffusion In The Nickel Electrode, Pauline De Vidts, Ralph E. White

Faculty Publications

In this paper we present a mathematical model of a sealed nickel-cadmium cell that includes proton diffusion and ohmic drop through the active material in the nickel electrode. The model is used to calculate sensitivity coefficients for various parameters in the model. These calculations show that the discharge voltage of the cell is affected mostly by the kinetics of the nickel reaction. Toward the end of discharge, proton diffusion also becomes important, because the proton diffusion process affects the active material utilization significantly. During charge, the cell voltage is mainly affected by the kinetics of the nickel reaction until the …

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Ac Impedance Studies On Metal Hydride Electrodes, Wenlin Zhang, M. P. Sridhar Kumar, Supramaniam Srinivasan, Harry J. Ploehn Jan 1995

Ac Impedance Studies On Metal Hydride Electrodes, Wenlin Zhang, M. P. Sridhar Kumar, Supramaniam Srinivasan, Harry J. Ploehn

Faculty Publications

The metal hydride (MHx) electrode is the negative electrode in one of the most advanced secondary batteries (i.e.,nickel/metal hydride). The objective of this study is to obtain insight on the mechanism of the hydriding/dehydridingreaction in the battery by using the electrochemical impedance spectroscopy (EIS) technique. An equivalent circuit for the MHx electrode reaction is proposed. The rate capability of charge and discharge of the MHx electrode is determined by thekinetics of the charge-transfer reaction at the alloy surface, which is mainly represented by the EIS responses in the lowfrequency region. Transient and pseudo-steady-state analyses …

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Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White Jan 1995

Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

Theconstant potential and constant current discharge techniques were used todetermine the hydrogen diffusion coefficients in an LaNi4.25Al0.75 electrode. The valuesobtained were 2.97 × 10–11 and 3.30 × 10–11 cm2/s, respectively. The advantages and disadvantages of these two techniques are discussed.

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The Effect Of Current And Nickel Nitrate Concentration On The Deposition Of Nickel Hydroxide Films, Christopher C. Streinz, Andrew P. Hartman, Sathya Motupally, John W. Weidner Jan 1995

The Effect Of Current And Nickel Nitrate Concentration On The Deposition Of Nickel Hydroxide Films, Christopher C. Streinz, Andrew P. Hartman, Sathya Motupally, John W. Weidner

Faculty Publications

An electrochemical quartz crystal nanobalance (EQCN) has been utilized to measure the mass of Ni(OH)2 films electrochemically deposited from Ni(NO3)2 solutions. The objective of this work was to quantify electrochemical deposition as a function of deposition conditions. The changing mass recorded on the EQCN was demonstrated to be the result of Ni(OH)2 deposition. Deposited mass was observed to increase proportionally with applied charge as suggested by previous investigators. Most significantly, the rate of deposition was found to decrease more than an order of magnitude as the Ni(NO3)2 concentration increased from 0.2 to …

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Proton Diffusion In Nickel Hydroxide Films: Measurement Of The Diffusion Coefficient As A Function Of State Of Charge, Sathya Motupally, Christopher C. Streinz, John W. Weidner Jan 1995

Proton Diffusion In Nickel Hydroxide Films: Measurement Of The Diffusion Coefficient As A Function Of State Of Charge, Sathya Motupally, Christopher C. Streinz, John W. Weidner

Faculty Publications

Electrochemical impedance spectroscopy (EIS) was used to measure the solid-state diffusion coefficient of protons in nickel hydroxide films at room temperature as a function of state of charge (SOC). A model for the complex faradaic impedance of the nickel hydroxide active material is presented and used to extract the diffusion coefficient of protons from the EIS data. Impedance data over a range of frequencies can be used to extract a constant diffusion coefficient without the knowledge of the initial mobile proton concentration or the form of the charge-transfer kinetic expression. The proton diffusion coefficient is a strong function of SOC …

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A Boundary-Layer Model Of A Parallel-Plate Electrochemical Reactor For The Destruction Of Nitrates And Nitrites In Alkaline Waste Solutions, Shailesh Prasad, John W. Weidner, Andrew E. Farell Jan 1995

A Boundary-Layer Model Of A Parallel-Plate Electrochemical Reactor For The Destruction Of Nitrates And Nitrites In Alkaline Waste Solutions, Shailesh Prasad, John W. Weidner, Andrew E. Farell

Faculty Publications

Electrochemical processes appear to be attractive for treating low level nuclear wastes. The development of a simple divided electrochemical-cell model operating in a batch mode, used for the reduction of nitrates and nitrites from nuclear wastes, is presented. This model, based on a boundary-layer approach, is simple and yet encompasses the key features of a previously developed distributed-parameter model that includes diffusion, migration, and convection as the flux components. Because it dramatically reduces computation time, this boundary-layer model is well suited for use in a complex interactive flowsheet model and for optimization studies. The boundary-layer model is used to predict …

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The Effect Of Temperature And Ethanol On The Deposition Of Nickel Hydroxide Films, Christopher C. Streinz, Sathya Motupally, John W. Weidner Jan 1995

The Effect Of Temperature And Ethanol On The Deposition Of Nickel Hydroxide Films, Christopher C. Streinz, Sathya Motupally, John W. Weidner

Faculty Publications

The objective of this work was to determine the effect of the temperature and the ethanol content of the Ni(NO3)2 solution on: (i) the efficiency of electrochemical deposition of nickel hydroxide; and (ii) the molecular weight of the deposited film. An electrochemical quartz crystal nanobalance (EQCN) was used to measure the mass of films electrochemically deposited from Ni(NO3)2 solutions and constant current discharges were used to determine the electrochemical capacity of the films. The data indicates that increasing the temperature increases both the efficiency of the deposition reaction and the …

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Electrowinning Of Non-Noble Metals With Simultaneous Hydrogen Evolution At Flow-Through Porous Electrodes I. Theoretical, Mahmoud M. Saleh, John W. Weidner, Badr G. Ateya Jan 1995

Electrowinning Of Non-Noble Metals With Simultaneous Hydrogen Evolution At Flow-Through Porous Electrodes I. Theoretical, Mahmoud M. Saleh, John W. Weidner, Badr G. Ateya

Faculty Publications

A mathematical model is developed to simulate the electrowinning of non-noble metals (e.g., Zn, Cr) within flow-through porous electrodes under the conditions of simultaneous evolution of hydrogen gas bubbles. The results of the model are presented as a function of several dimensionless groups representing kinetics, mass transfer, ohmic resistance, and gas bubbles. These coupled, nonlinear effects are investigated by examining the distributions of the metal reduction and hydrogen evolution currents, coulombic efficiency of the metal electrowinning reaction, and gas void fractions under a series of limiting conditions. The gas bubbles accentuate the nonuniform distribution of the potential and …

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A Parallel-Plate Electrochemical Reactor Model For The Destruction Of Nitrate And Nitrite In Alkaline Waste Solutions, D. H. Coleman, Ralph E. White, D. T. Hobbs Jan 1995

A Parallel-Plate Electrochemical Reactor Model For The Destruction Of Nitrate And Nitrite In Alkaline Waste Solutions, D. H. Coleman, Ralph E. White, D. T. Hobbs

Faculty Publications

A parallel-plate electrochemical reactor model with multiple reactions at both electrodes and anolyte and catholyte recirculation tanks was modeled for the electrochemical destruction of nitrate and nitrite species in an alkaline solution. The model can be used to predict electrochemical reaction current efficiencies and outlet concentrations of species from the reactor, given inlet feed conditions and cell operating conditions. Also, predictions are made for off-gas composition and liquid-phase composition in the recirculation tanks. The results of case studies at different applied potentials are shown here. At lower applied potentials, the model predictions show that the destruction process is more energy …

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Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White Jan 1995

Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The constant potential and constant current discharge techniques were used to determine the hydrogen diffusion coefficients in an LaNi4.25Al0.75 electrode. The values obtained were 2.97 × 10–11 and 3.30 × 10–11 cm2/s, respectively. The advantages and disadvantages of these two techniques are discussed.

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Use Of Underpotential Deposition Of Zinc To Mitigate Hydrogen Absorption Into Monel K500, G. Zheng, Branko N. Popov, Ralph E. White Jan 1994

Use Of Underpotential Deposition Of Zinc To Mitigate Hydrogen Absorption Into Monel K500, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

Polarization experiments and a potentiostatic pulse technique have been used to show that a monolayer coverage of zinc effectively inhibits the absorption of hydrogen into Monel K500. By depositing a monolayer of zinc on Monel K500, the hydrogen evolution reaction and hydrogen ingress flux rate were reduced by 60%.

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A Finite-Difference Method For Pseudo-Two-Dimensional Boundary Value Problems, Z. Mao, Ralph E. White Jan 1994

A Finite-Difference Method For Pseudo-Two-Dimensional Boundary Value Problems, Z. Mao, Ralph E. White

Faculty Publications

A finite-difference method is presented for solving pseudo-two-dimensional boundary-value problems. The sparse and nearly block tridiagonal properties of the matrices generated by using the finite-difference method for problems of this type are fully utilized and maintained, which yields a method that is highly efficient in the use of storage space and computation. An example shows that the central process unit time required by the method is significantly less than that required by an alternative method.

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Effect Of Proton Diffusion, Electron Conductivity, And Charge-Transfer Resistance On Nickel Hydroxide Discharge Curves, John W. Weidner, Paul Timmerman Jan 1994

Effect Of Proton Diffusion, Electron Conductivity, And Charge-Transfer Resistance On Nickel Hydroxide Discharge Curves, John W. Weidner, Paul Timmerman

Faculty Publications

Constant-current discharge curves for the nickel hydroxide electrode are simulated assuming resistances due to diffusion of protons and conduction of electrons through the nickel hydroxide film, and charge-transfer resistance at the film/electrolyte interface contribute to the polarization losses of the electrode. Good qualitative agreement is observed between the model predictions and experimental discharge curves. The results suggest that polarization losses due to diffusional limitations of protons is a critical factor in determining the characteristics of the discharge curve. Ohmic resistance has a significant effect on the discharge curves at the end of discharge, and charge-transfer resistance is a minor contributor …

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Theoretical Analysis Of The Discharge Performance Of A Niooh/H2 Cell, Z. Mao, P. De Vidts, Ralph E. White, John Newman Jan 1994

Theoretical Analysis Of The Discharge Performance Of A Niooh/H2 Cell, Z. Mao, P. De Vidts, Ralph E. White, John Newman

Faculty Publications

A mathematical model is presented for the discharge of a NiOOH/H2 cell. This model includes diffusion and migration in the electrolyte phase as well as proton diffusion and ohmic drop across the solid active material in the porous nickelelectrode. A theoretical analysis of the cell performance is presented for different design parameters using this model. It is predicted that proton diffusion in the solid active material is the main factor in limiting the cell voltage and the utilizationof the active material. It is also predicted that use of a thick nickel electrode is an effective method for increasing electrode …

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Thermal Characteristics Of A Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White Jan 1994

Thermal Characteristics Of A Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White

Faculty Publications

The maximum allowable temperature difference inside a nickel-hydrogen battery to avoid water relocation was calculated by using a graphical method together with a vapor pressure vs. temperature correlation equation for water vapor over potassium hydroxide solution. An equation was developed for this maximum allowable temperature difference for vessel-wall temperatures from 0 to 30°C and potassium hydroxide concentrations from 20 to 32%. A heat-generation equation for the nickel-hydrogen battery was used to investigate the effect of the location of heat generation on the maximum temperature in the cell and the temperature distribution in the cell.

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The Role Of Thallium As A Hydrogen Entry Promoter On Cathodically Polarized Hy-130 Steel, G. Zheng, Branko N. Popov, Ralph E. White Jan 1994

The Role Of Thallium As A Hydrogen Entry Promoter On Cathodically Polarized Hy-130 Steel, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

Hydrogen permeation experiments were carried out to investigate the effect of thallium on hydrogen entry into HY-130steel. These experiments show that the presence of thallium ions in an electrolyte drastically increase the hydrogen entry rate. The hydrogen entry efficiency and hydrogen surface coverage were increased by a factor of 10 and 6, respectively. In order to fit the permeation experimental data, the Iyer-Pickering-Zamanzadeh (I-P-Z) hydrogen permeation model was modified by including a mass-transfer term in the discharging equation. The relationship between hydrogen permeation and the hydrogen evolution reaction were investigated and new relationships were obtained.

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Mathematical Modeling Of The Formation Of Calcareous Deposits On Cathodically Protected Steel In Seawater, J. F. Yan, T. V. Nguyen, Ralph E. White, R. B. Griffin Jan 1993

Mathematical Modeling Of The Formation Of Calcareous Deposits On Cathodically Protected Steel In Seawater, J. F. Yan, T. V. Nguyen, Ralph E. White, R. B. Griffin

Faculty Publications

A first principle mathematical model of the formation of calcareous deposits on a cathodically protected steel rotatingdisk electrode in seawater is presented. The model includes equations which transport phenomena, electrochemical reactions,precipitation reactions, and a homogeneous reaction involved in the formation of calcareous deposits on an electrodesurface. Predicted concentration profiles show that a high concentration of OH– ions on the electrode surface leads to the formation of calcareous deposits. The calcareous deposits contain mostly CaCO3, but the initial deposits are predicted to contain more Mg(OH)2 than CaCO3. The predicted calcareous deposits on the electrode surface …

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A Water And Heat Management Model For Proton-Exchange-Membrane Fuel Cells, Trung V. Nguyen, Ralph E. White Jan 1993

A Water And Heat Management Model For Proton-Exchange-Membrane Fuel Cells, Trung V. Nguyen, Ralph E. White

Faculty Publications

Proper water and heat management are essential for obtaining high-power-density performance at high energy efficiency for proton-exchange-membrane fuel cells. A water and heat management model was developed and used to investigate the effectiveness of various humidification designs. The model accounts for water transport across the membrane by electro-osmosis and diffusion, heat transfer from the solid phase to the gas phase and latent heat associated with water evaporation and condensation in the flow channels. Results from the model showed that at high current densities (> 1 A/cm2) ohmic loss in the membrane accounts for a large fraction of the …

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Surface Treatment For Mitigation Of Hydrogen Absorption And Penetration Into Aisi 4340 Steel, G. Zheng, Branko N. Popov, Ralph E. White Jan 1993

Surface Treatment For Mitigation Of Hydrogen Absorption And Penetration Into Aisi 4340 Steel, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The effectiveness of underpotential deposition of Pb onto a membrane made of AISI 4340 steel on the reduction of the hydrogen evolution reaction on the membrane and the degree of hydrogen ingress into the membrane was determined. In the presence of a monolayer coverage of Pb on the membrane surface, the hydrogen evolution currents were reduced by a factor of two compared with the values obtained on bare steel, and the steady-state hydrogen permeation flux through the steel membranes was reduced by 71%.

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Impedance Spectroscopy As A Nondestructive Health Interrogation Tool For Lithium-Bcx Cells, Branko N. Popov, W. Zhang, E. C. Darcy, Ralph E. White Jan 1993

Impedance Spectroscopy As A Nondestructive Health Interrogation Tool For Lithium-Bcx Cells, Branko N. Popov, W. Zhang, E. C. Darcy, Ralph E. White

Faculty Publications

The objective of this investigation was to study the growth of thick passivating layers on the Li anode in Li/BCX(Li/SOCl2 + BrCl) cells which were stored for a period of 3 years. Impedance spectroscopy and equivalent circuit models were used to determine characterizing parameters for these cells. The equivalent circuit used for virgin cells includes a faradic contribution and diffusion of the electroactive species. The equivalent circuit for batteries stored 1 or 2 years includes the impedance of a metal/passive film interface, the resistance of the film, and the impedance of the passivating film/electrolyte interface. The equivalent circuit used …

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Using Electrochemical Impedance Spectroscopy As A Tool For Organic Coating Solute Saturation Monitoring, Branko N. Popov, Mohammed A. Alwohaibi, Ralph E. White Jan 1993

Using Electrochemical Impedance Spectroscopy As A Tool For Organic Coating Solute Saturation Monitoring, Branko N. Popov, Mohammed A. Alwohaibi, Ralph E. White

Faculty Publications

Electrochemical impedance spectroscopy (EIS) has been used to study the solute uptake for epoxy/phenolic (E/p) andepoxy/amine (E/a) thick-coated mild steel samples immersed for 160 days in 3.5 weight percent NaCl solution exposed to air. Samples with thicknesses of approximately 200 µm with an exposed surface area of 22.6 cm2 were used to follow solute saturation of the organic coating. Good agreement was obtained between the calculated and measured coating capacitance when, according to the diffusion equation, the coating capacitance was plotted against exposure time.

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Galvanostatic Pulse And Pulse Reverse Plating Of Nickel-Iron Alloys From Electrolytes Containing Organic Compounds On A Rotating Disk Electrode, Branko N. Popov, Ken-Ming Yin, Ralph E. White Jan 1993

Galvanostatic Pulse And Pulse Reverse Plating Of Nickel-Iron Alloys From Electrolytes Containing Organic Compounds On A Rotating Disk Electrode, Branko N. Popov, Ken-Ming Yin, Ralph E. White

Faculty Publications

Linear sweep voltammetry, galvanostatic pulse, and pulse reverse techniques were used to study the plating of nickel-iron alloys in the presence of organic additives. The effects of pulse current densities, ip, reverse current densities, ir, rotation speed of disk electrode, and the presence of organic additives on deposition of nickel-iron alloys are evaluated. The observed phenomena can be explained by the concentration depletion of reactants (or products), and the surface coverage of the additives on the electrode. A new formulation of the plating bath is defined.

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Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt: Effects Of Partial Pressure Of Carbon Dioxide And Temperature, Bhasker B. Dave, Ralph E. White, Supramaniam Srinivasan, A. John Appleby Jan 1993

Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt: Effects Of Partial Pressure Of Carbon Dioxide And Temperature, Bhasker B. Dave, Ralph E. White, Supramaniam Srinivasan, A. John Appleby

Faculty Publications

Effects of partial pressure of carbon dioxide and temperature on oxygen reduction kinetics on a gold electrode in a lithium carbonate melt were examined using electrochemical impedance spectroscopic (EIS) and linear sweep voltammetric techniques. The impedance spectra were analyzed by a complex nonlinear least squares method, using the Randles-Ershler equivalent circuit model, to determine the electrode-kinetic and the mass-transfer parameters such as the charge-transfer resistance and the Warburg coefficient. The cyclic voltammetric measurements indicated that the oxygen reduction process in lithium carbonate melt is "reversible" up to 200 mV/s. The product DC0 determined by cyclic voltammetry agreed well …

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Thermal Analysis Of Spirally Wound Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White Jan 1993

Thermal Analysis Of Spirally Wound Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White

Faculty Publications

A thermal analysis of Li/BCX and high rate Li/SOCl2 cells is presented. The thermal model developed was used to study the effect of ambient temperature of discharge (0–40°C) on Li/BCX cells discharged at the same rate. The model predictions show that ambient temperature of discharge was critical in thermal management of the cell. For forced convection cooled cells, the model predicted that ambient temperature near room temperature (25°C) was required to achieve the lowest maximum temperature rise in the cell. Inclusion of the effects of reaction products to the model predictions showed that a constant composition assumption may be …

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Thermal Mathematical Modeling Of A Multicell Common Pressure Vessel Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White Jan 1992

Thermal Mathematical Modeling Of A Multicell Common Pressure Vessel Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White

Faculty Publications

A two-dimensional and time-dependent thermal model of a multicell common pressure vessel (CPV) nickel-hydrogen battery was developed. A finite element solver called PDE/Protran was used to solve this model. The model was used to investigate the effects of various design parameters on the temperature profile within the cell. The results were used to help find a design that will yield an acceptable temperature gradient inside a multicell CPV nickel-hydrogen battery. Steady-state and unsteady-state cases with a constant heat generation rate and a time-dependent heat generation rate were solved.

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Comparison Of Heat-Fin Materials And Design Of A Common-Pressure-Vessel Nickel-Hydrogen Battery, Junbom Kim, Ralph E. White Jan 1992

Comparison Of Heat-Fin Materials And Design Of A Common-Pressure-Vessel Nickel-Hydrogen Battery, Junbom Kim, Ralph E. White

Faculty Publications

A two-dimensional, axisymmetric, and time-dependent thermal model was developed to study the temperature behavior of the cylindrically shaped common-pressure-vessel nickel-hydrogen cell. A differential-energy-balance equation was used as the governing equation. A finite-element software package called PDE/Protran was used to solve this model. Different materials such as copper, copper beryllium, silver, and sterling silver were compared as heat-fin materials. The heat-fin geometry (thickness and height) and spacing were tested to find a design that yielded an acceptable temperature gradient inside a nickel-hydrogen cell. Pulse heat-generation rates were tested and correlated with the time-dependent heat-generation cases.

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Mathematical Modeling Of A Primary Zinc/Air Battery, Z. Mao, Ralph E. White Jan 1992

Mathematical Modeling Of A Primary Zinc/Air Battery, Z. Mao, Ralph E. White

Faculty Publications

The mathematical model developed by Sunu and Bennion has been extended to include the separator, precipitation of both solid ZnO and K2Zn(OH)4, and the air electrode, and has been used to investigate the behavior of a primary Zn-Air battery with respect to battery design features. Predictions obtained from the model indicate that anode material utilizationis predominantly limited by depletion of the concentration of hydroxide ions. The effect of electrode thickness on anode material utilization is insignificant, whereas material loading per unit volume has a great effect on anode material utilization; a higher loading lowers both the …

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Parameter Sensitivity And Optimization Predictions Of A Hydrogen/Oxygen Alkaline Fuel Cell Model, Michael C. Kimble, Ralph E. White Jan 1992

Parameter Sensitivity And Optimization Predictions Of A Hydrogen/Oxygen Alkaline Fuel Cell Model, Michael C. Kimble, Ralph E. White

Faculty Publications

A mathematical model is used to predict parameter sensitivities and optimal design parameters for a hydrogen/oxygen alkaline fuel cell. A sensitivity analysis of the various transport and electrode kinetic parameters indicates which parameters have the most influence on the predicted current density and over which range of potentials these parameters affect the fuel-cell performance the most. This information can be used to decide which parameters should be optimized or determined more accurately through further modeling or experimental studies. The effect of various design parameters on the limiting current density are investigated to determine if optimal values exist for the parameters. …

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The Self-Discharge Of The Niooh/Ni(Oh)2 Electrode Constant Potential Study, Z. Mao, Ralph E. White Jan 1992

The Self-Discharge Of The Niooh/Ni(Oh)2 Electrode Constant Potential Study, Z. Mao, Ralph E. White

Faculty Publications

Hydrogen oxidation currents at a NiOOH/Ni(OH)2 electrode were measured directly at constant potentials for various hydrogen pressures and states of charge. It was found that the hydrogen oxidation current is linearly proportional to the hydrogen pressure at all electrode potentials and that the logarithm of the anodic current is a linear function of electrode potential. It was also found that hydrogen oxidation on the nickel substrate material was strongly inhibited by the presence of nickel hydroxide on the substrate surface. By comparing the currents for hydrogen oxidation and oxygen evolution on the NiOOH/Ni(OH)2 electrode and on a nickel …

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Mathematical Modeling Of Cathodic Protection Using The Boundary Element Method With A Nonlinear Polarization Curve, J. F. Fan, S. N. R Pakalapati, T. V. Nguyen, Ralph E. White, R. B. Griffin Jan 1992

Mathematical Modeling Of Cathodic Protection Using The Boundary Element Method With A Nonlinear Polarization Curve, J. F. Fan, S. N. R Pakalapati, T. V. Nguyen, Ralph E. White, R. B. Griffin

Faculty Publications

The distributions of potential and current density around a cathodically protected pipeline in seawater were determined using the boundary element technique. A nonlinear polarization curve for a low carbon steel in artificial sea water was obtained from dc-potentiodynamic measurements and was fitted for use as the boundary condition on the pipe. The program was used to evaluate cases in which one or two aluminum sacrificial anodes are used to protect a low carbon steelpipe in seawater. The results show that the number of anodes, the sizes of the anodes, and the distance between the anodes and the cathode are of …

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