Sökning: "positronium"
Hittade 5 avhandlingar innehållade ordet positronium.
1. Macroscopic Volume and Free Volume of Polymer Blends and Pressure-densified Polymers
Sammanfattning : The macroscopic volume V as a function of pressure P and temperature T is obtained from PVT measurements. PVT data is sensitive to the state of polymers and changes therein. Moreover, PVT data gives access to the free-volume fraction. LÄS MER
2. Free Volume Determination in Polymers and Polymer Blends
Sammanfattning : 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. LÄS MER
3. Free Volume and Mesopores in Polymer Nanocomposites
Sammanfattning : 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. LÄS MER
4. Resonances in Three-Body Systems
Sammanfattning : Three particles interacting via Coulomb forces represent a fundamental problem in quantum mechanics with no known exact solution. We have investigated resonance states composed of three particles interacting via Coulombic and more general potentials in non-relativistic quantum mechanics, using the complex scaling method. LÄS MER
5. Free Volume Depth Profiling at Polymer Surfaces and Interfaces
Sammanfattning : 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. LÄS MER