Search for dissertations about: "gas porosity"

Showing result 1 - 5 of 81 swedish dissertations containing the words gas porosity.

2. 1. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron

   Author : Jessica Orlenius; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core binders; Gas porosity; hydrogen; grey iron; gas absorption; nitrogen; oxygen; gas evolution rate; green sand; mould filling; gas volume; gas solubility;

   Abstract : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. READ MORE

4. 2. On Diffusion Transport Properties in Fuel Cell Gas Diffusion Layers Using the Lattice Boltzmann Method

   Author : Mayken Espinoza Andaluz; Värmeöverföring; []
   Keywords : PEFC; lattice Boltzmann method; gas diffusion layers; porosity; Gas-phase tortuosity; permeability; inertial coefficient; diffusibility; pore-scale modeling;

   Abstract : The polymer electrolyte fuel cell (PEFC) is considered as one of the most promising devices for providing efficient, clean and noiseless conversion of chemical energy to electrical energy. This device can provide electrical and thermal energy for transport, mobile and stationary applications ranging in a wide range of power requirements. READ MORE

5. 3. High Clay Content Cellulose Nanocomposites for Mechanical Performance and Fire Retardancy

   Author : Lilian Medina; Lars Berglund; Jeffrey W. Gilman; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; nanocellulose; nanofibril; nanofiber; CNF; nanoplatelet; nanostructure; tactoid; montmorillonite; MTM; foam; aerogel; porosity; PVA; poly vinyl alcohol ; epoxy; moisture; biocomposite; biomaterial; biobased; flame; cone calorimetry; gas barrier; coating; film.; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : Materials based on wood can offer sustainable alternatives to fossil-based plastics and composites, and show interesting mechanical properties. However, the issue of their flammability is generally unresolved. In this thesis, eco-friendly, fire retardant clay-cellulose nanofibril materials are investigated. READ MORE

6. 4. On Microstructural Analysis of Porous Media Existing in Fuel Cells Using the Lattice Boltzmann Method

   Author : Mayken Espinoza Andaluz; Värmeöverföring; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Porous media; lattice Boltzmann method; microscale; Gas-phase tortuosity; Porosity; Fuel Cell;

   Abstract : This Licentiate thesis aims to gain understanding related to the fluid behavior in porous media existent in fuel cells (FCs) at microscale. In order to achieve this; the widely used methodology for solving problems in porous media has been applied, the Lattice Boltzmann Method (LBM). READ MORE

7. 5. Analysis of Deformation of Gas Diffusion Layers and the Impact on Performance of PEM Fuel Cells

   Author : Jiatang Wang; Värmeöverföring; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; PEM fuel cell; compression ratio; assembly pressure; porosity; deformed GDL; electric resistance; transport phenomena; model; performance; analysis; OpenFOAM;

   Abstract : Proton exchange membrane (PEM) fuel cells have been promoted due to significant breakthroughs in various aspects and increasing public interests. The porous features of the gas diffusion layer (GDL) and the necessary assembly processes generate localized pressure forces on the channel/shoulder structure of the bi-polar plates (BPP). READ MORE