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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Polarization curve"”.
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Design of a microfluidic device for the analysis of biofilm behavior in a microbial fuel cell
… · m⁻², (28mV at open circuit) in the first ever polarization curve for a laminar-flow microbial fuel cell. A model was developed for biofilm behavior incorporating shear and pore pressure as mechanisms for biofilm loss. The model agrees with experimental observations on fluid flow through …
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Health conscious energy management strategies for fuel cell/battery hybrid vehicles
… their lifetime. ☐ A detailed model of the polarization curve of a fuel cell stack is presented. The time- evolving polarization curve indicates the performance decay of the fuel cell over its lifetime. The performance decay is based on the decrease of electrochemical surface area (ECSA) …
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Experimental investigation of novel proton exchange membrane fuel cell and battery integrated system
… PEM fuel cell stack are performed through the polarization curve, energy efficiency, exergy efficiency, and open circuit voltage. Furthermore, the performance evaluation of the fuel cell and battery integrated system is performed. The performance assessments of the system are performed through …
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Development and Evaluation of a Test Apparatus for Fuel Cells
… of the device included measurement of a polarization curve for a 5-cell, 1 kW stack. An effective test apparatus is imperative for stack performance testing, model evaluation, and investigation of new fuel cell technology. This apparatus was designed to measure and control the mass flow …
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Sulfide stress cracking resistance of API-X100 high strength low alloy steel in H2S environments
… study was conducted by means of electrochemical polarization techniques and constant load (proof ring) testing. Microstructural analysis and electrochemical polarization results for X100were compared with those for X80, an older generation HSLA steel. Uniaxial constant load SSC testing was …
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Microfabrication and electrical characterization of lead-free sodium potassium niobate thin film ribbons on conformal substrates
… different tested substrates as the capacitance, polarization curve, and leakage current of all the devices are in the same range and are close as the ribbons are swept from -40 V to 40 V.
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Multi-dimensional modeling of transient transport phenomena in molten carbonate fuel cells
… mechanisms predicted the linear region of the polarization curve accurately. However, none of these mechanisms showed a downward bent in the polarization curve. A positive exponent for the carbon-dioxide mole fraction is probably essential in obtaining the downward bent (“knee”) at high current …
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A model-based approach for the development of a bioelectrochemical sensor for biochemical oxygen demand in wastewater
… thereby generating a measurable current. A polarization curve measures the response of the current generated to changes in the anode potential. In this study, four continuously operated microbial electrolysis cells with two different anode materials with differing surface properties have …
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Dynamic modelling and emulation of a high temperature proton exchange membrane fuel cell (HT PEMFC)
… dynamic operating conditions. Phenomena such as polarization curve hysteresis and fuel starvation is investigated, simulated and reproduced with the emulator system. The experimental results are compared with that of an actual HT PEM FC stack and evaluated. It was shown that the final system is …
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Microchannel flow fields for polymer electrolyte fuel cells
… Several diagnostic measurements including polarization curve, high frequency resistance, electrochemical impedance spectroscopy, pressure drop co-efficient and cell voltage monitoring were conducted to understand the water management behaviour and trends in the two different aforementioned …
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System Level Modeling of Thermal Transients in PEMFC Systems
… size. The electrical model employs a generalized polarization curve to approximate system performance and efficiency parameters needed for the other components of the model. General parameters of a stack's individual cells must be known to scale the stack model. These parameters are usually known …
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Experimental and numerical analysis of fuel cells
… to simplify them or to achieve best fits with polarization data. In this work, physical phenomena are not assumed but determined via newly developed experimental and numerical techniques. The experimental fixtures and procedures were used to find better ways to control parameters of gas flow …
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Stress corrosion cracking of austenitic stainless steels
… with respect to applied potential zones on the polarization curve, i.e. cathodic, active (zone 1), active/passive (zone 2) and passive/transpassive (zone 3). It was found that hydrogen embrittlement (HE) was the main cracking process in zone 1 and cathodic zone for annealed specimens. For …
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Model of the Air System Transients in a Fuel Cell Vehicle
… the fuel cell current and the pressure with the polarization curve. The model of the fuel cell system was implemented in Matlab/Simulink. Several open and closed loop simulations were run to test the functionality of the fuel cell system model. The gross and net powers of the fuel cell system …
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Investigation of Water Transport Parameters and Processes in the Gas Diffusion Layer of PEM Fuel Cells
… simplify the model or to achieve good fits with polarization data. In this work, the constitutive relations are not assumed but are determined via newly developed experimental techniques. The experimental fixtures and procedures were used to characterize common GDL materials including carbon …
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Understanding of Ammonia Transport In Pem Fuel Cells
… electrode relative to ERE was measured during a polarization curve. The data showed the measurement of individual electrode was extremely affected by the misalignment between two electrodes. We compare the overpotential measured from the reference electrode and the calculated overpotential from …
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Reference Electrode Development in Polymer Electrolyte Membrane (PEM) Electrolyzer Assembly for Novel Investigation of Electrodes
… parametric study confirmed sufficient hydrogen polarization of the RE for operating conditions at low current density, low temperature, and low water feed rates. Application of the RE was successfully demonstrated through investigation of the oxygen evolution and hydrogen evolution reaction …
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Synthesis, Characterization and Corrosion Inhibition Investigation of substituted triazines on aluminium and mild steel in 1M HCl: Experimental and Theoretical approach
… impedance spectroscopy (EIS), potentiodynamic polarization curve (PDP), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX), and density functional theory approach (DFT). The weight loss measurement was carried out at different temperatures (303 to 323 K) and …
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SYNTHESIS AND CHARACTERIZATION OF NEW ELECTROCATALYTIC MATERIALS TO IMPROVE THE PERFORMANCE, OPERABILITY AND LIFE-TIME OF PEMFCS
… electrolyte fuel cell setup. Subsequently, the polarization curves obtained in the fuel cell are analyzed by means of a simplified model and important parameters about the catalytic layer are obtained. A comparative discussion of these results indicated the electrochemical performances of the …
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In situ Nanoscale Quantification of Corrosion Kinetics by Quantitative Phase Microscopy
… conditions. Electrochemical tests via stepwise polarization and solution chemistry through collected aliquots of outflow solution were also performed alongside the nanoscale SMI experiment to simultaneously provide corroborating corrosion rate measurements. This innovative approach to measuring …