Search for dissertations about: "Thermal aging"

Showing result 1 - 5 of 60 swedish dissertations containing the words Thermal aging.

2. 1. Characterization methods and modelling for Li-ion batteries: entropy, impedance, pressure, diffusivity & temperature swings induced aging

   Author : Zeyang Geng; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; characterization methods; swelling; temperature swing; model; impedance; lifetime; Li-ion batteries; thermal; pressure; entropy; aging;

   Abstract : Lithium-ion batteries are commonly used for energy storage systems, and temperature is one key impact factor on the cell performance and lifetime. In literature, the focus has been on the ambient temperature of the test condition, and there is little discussion about how the temperature swing during cycling affects the battery lifetime. READ MORE

4. 2. Aging effects on commercial lean NOx trap catalysts

   Author : Jesus De Abreu Goes; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aging; thermal degradation; sulfur poisoning; characterization; commercial lean NOx traps; NOx storage and reduction;

   Abstract : As a countermeasure to global warming, vehicles with low carbon emissions are being investigated by promoting lean-burn engines and high combustion efficiencies. However, one limitation to the increasing use of these engines is the need to develop corresponding catalytic systems for controlling the nitrogen oxide (NOx) emissions in their lean exhaust. READ MORE

5. 3. Modeling and Testing of Insulation Degradation due to Dynamic Thermal Loading of Electrical Machines

   Author : Zhe Huang; Industriell elektroteknik och automation; []
   Keywords : thermal degradation; thermal cycle; dynamic temperature; thermal-mechanical; fatigue; electrical insulation system; accelerated testing; condition monitoring; electrical machine; electrified vehicles;

   Abstract : Electrical machines in electrified vehicles are subjected to dynamic loadings at different driving conditions, which results in dynamic temperatures. The aging of the Electrical Insulation System (EIS) in electrical machines is caused by these dynamic temperatures, namely high average temperatures and temperature cycles. READ MORE

6. 4. Characterization of nano-scale materials for interconnect and thermal dissipation application in electronics packaging

   Author : Xin Luo; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal conductivity; thermal interface material; thermal management; boron nitride fiber; electrospun nanofiber; lead-free solder; carbon fiber; nano-scale oxide layer; metal matrix composite;

   Abstract : This thesis focuses on studies of nano-scale materials in electronic packaging applications with respect to following aspects: surface analysis of nano-scale oxide of lead-free solder particles, and thermal performance and mechanical property studies of nano-scale fiber and metal composite-based thermal interface materials. The composition and thickness of the solder oxide have a direct impact on the quality of interconnects and the reliability of a packaged system. READ MORE

7. 5. Plasticized Poly (lactic acid) Films - Preparation and Properties

   Author : Nadia Ljungberg; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; phase separation; aging; thermal properties; dynamic mechanical properties; processing; film preparation; oligomer synthesis; poly lactic acid ; plasticizers; migration; cold crystallization; Polymer technology; biopolymers; Polymerteknik;

   Abstract : The development of biodegradable polymers from renewable resources is of importance in order to prevent the depletion of fossil fuels and the increasing emissions of carbon dioxide to the atmosphere caused by the commodity plastics of today. However, to be able to replace these non-environmentally friendly materials, production costs of biodegradable polymers have to be decreased and their physical properties need to be enhanced. READ MORE