Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 13 of 13 for “"Diffusion layers"”.
-
Porous titanium felts as alternative metal gas diffusion layers for low temperature PEM fuel cells
… A key component of the PEMFC is the gas diffusion layer (GDL) which facilitates reactant transport and water management within the cell. The GDL is conventionally carbon-based which makes it susceptible to degradation during operation within the oxidative environment of the PEMFC. This …
-
Growth and use of Carbon Nanotube Nanoforests as Gas Diffusion Layers in Industrial-Scale Proton Exchange Membrane Fuel Cells
… and flooding due to excess water. Gas diffusion layers are a component within the fuel cell designed for the functions of permeability, electrical conductivity, mechanical strength, and water management. For this research, the production and use of carbon nanotube nanoforests for gas …
-
A comprehensive fractal approach in determination of the effective thermal conductivity of gas diffusion layers in polymer electrolyte membrane fuel cells
… of the effectiveness thermal conductivity of gas diffusion layers (GDL) used in polymer electrolyte membrane fuel cells (PEMFC‟s). This is one of the factors affecting the durability of a fuel cell and need to get a solution to minimize costs and optimize the use of electrodes and cells. The main …
-
Technoeconomic Analysis and Design of CO₂ Capture and Conversion Systems
… with regards to the design of electrode gas diffusion layers. We design and construct a CO₂ conversion reactor for testing of next generation gas diffusion layers. Strong baseline performance of the reactor is validated with a 47% Faradaic Efficiency towards C₂H₄ at 200mA/cm².
-
Low platinum loading electrospun electrodes for proton exchange membrane fuel cells
… was similar to that of sputtered commercial gas diffusion layers in single cell fuel cell tests. However, sputtered platinum electrodes performed significantly worse than commercial thin film electrodes due to high activation and concentration voltage losses. Cyclic voltammetry and rotating disc …
-
Bulk Growth of Semiconductor Crystals in a Magnetic Field: A Study of Dopant Transport
… We divide the semiconductor melt into (1) mass-diffusion boundary layers where convective and diffusive mass transfer are comparable, and (2) a core region where diffusion is negligible, so that the concentration of each fluid particle is constant. A Lagrangian description of motion is used to …
-
Evaluation and Characterization Testing of Liquid Fuel Cell Chemistry for Applications in Unmanned Underwater Vehicles
… UUVs. Additionally, LFCs often make use of Gas Diffusion Layers (GDLs), despite the lack of gaseous species present on either the oxidation side, reduction side, or both. This thesis seeks to investigate potential fuel cell improvements by eliminating GDLs from a Membrane Electrode Assembly …
-
Mathematical Simulation of Direct Glucose Fuel Cell
… domain consisting of electrodes, gas diffusion layers, anion exchange membrane, catalyst layers and flow channels. These equations were solved using numerical techniques such as Runge-Kutta 4th order method and Shooting technique in MATLAB. The influence of various parameters such as …
-
Sliding wear of nitrided steels
… in determining the wear rate through nitrided diffusion layers. A thick and porous compound layer produced by gas nitriding showed a poor wear behaviour owing to its brittleness, while a thin nitrocarburized E-Fe3N compound layer exhibited a low wear rate. There was no significant difference …
-
Towards a Membrane Electrode Assembly for a Thermally Regenerative Fuel Cell
… (the alcohol-ketone pair). Catalyst coated gas diffusion layers or catalyst coated membranes were made to test the stability of the polymers in the catalyst bed when exposed to the alcohol-ketone pair. If the polymer was compatible with the alcohol-ketone pair, MEAs were constructed using this …
-
Understanding Electrode-Electrolyte Interfaces with Metal Dissolution and Redeposition Chemistry
… cycling conditions. Amorphous TiO2 surface layers can be formed on WO3 electrodes by adding exotic Ti cations to the electrolyte, and slow electrochemical cycling. The dissolution and redeposition of electrodes and surface coatings are intertwined, helping to establish a …
-
Factors Affecting Redox Magnetohydrodynamics for Flow in Small Volumes
… that the magnetic force resides primarily in the diffusion layer in these systems, not in the electrolyte between the counter and working electrodes. The effects of channel and working electrode geometry also supported this conclusion. The outcome has important ramifications in designing …