Search for dissertations about: "positron lifetime"
Showing result 1 - 5 of 16 swedish dissertations containing the words positron lifetime.
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1. Investigation of Nuclear Materials with Positron Measurements
Abstract : Positron Annihilation Lifetime Spectroscopy can be used to characterize radia- tion-induced material defects to subsequently optimize nuclear materials with respect to radiation damage. Nuclear Systems of the future such as Generation IV and fusion concepts demand high performance from structural materials, comprising a material's stability in highly-radiative and hot environments. READ MORE
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2. Free Volume Depth Profiling at Polymer Surfaces and Interfaces
Abstract : Pulsed low energy positron beams provide a unique and non-destructive tool to depth probe the free volume of polymers at surfaces and interfaces. Since the employment of low energy positron beams in polymer research is an emerging technique, some focus in this thesis has been on extracting methods and equations needed to interpret the experimental data. READ MORE
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3. Radiation Detection Techniques for the Enhancement of Nuclear Safety
Abstract : The hazard originating from the use of nuclear materials in various areas of the society necessitates a number of experimental techniques for controlling and increasing the safety connected to radioactive substances.The following thesis is divided into two parts, representing different aspects to the detection of radiation effects. READ MORE
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4. Free Volume Determination in Polymers and Polymer Blends
Abstract : The free volume of a polymer, which corresponds to the unoccupied regions accessible to segmental motions, is an important parameter for understanding and predicting many of its characteristic properties. The concept of free volume is the basis for understanding the molecular mobility in polymers. READ MORE
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5. Free Volume and Mesopores in Polymer Nanocomposites
Abstract : The free volume in polymers is coupled to several important physical properties, such as density, viscosity and gas diffusivity. The physical properties of polymers close to a solid surface have been shown to be significantly perturbed as compared to their bulk state. READ MORE