Sökning: "fundamental cause theory"

Visar resultat 21 - 25 av 26 avhandlingar innehållade orden fundamental cause theory.

1. 21. Scale and Stress Effects on Hydro-Mechanical Properties of Fractured Rock Masses

   Författare :Alireza Baghbanan; Lanru Jing; Jian Zhao; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aperture-trace length correlation; Discrete Fracture Network DFN ; Representative Elementary Volume REV ; Strength; Stress-Strain curve; Discrete Element Method DEM ; Stress effect; Deformability of fractures; Earth sciences; Geovetenskap;

   Sammanfattning : In this thesis, the effects of size and stress on permeability, deformability and strength of fractured rock masses are investigated. A comparison study was carried out to examine the effects of considering, or not considering, the correlation between distributions of fracture apertures and fracture trace lengths on the hydro-mechanical behavior of fractured rocks. LÄS MER

3. 22. Elasto-hydrodynamic film formation in heavily loaded rolling-sliding contacts : Influence of surface topography on the transition between lubrication regimes

   Författare :Jonny Hansen; Roland Larsson; Marcus Björling; Guillermo Morales-Espejel; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : To meet the stringent demands set on future gear transmissions, and to allow for manufacturers to make them more efficient and durable, it is essential to understand what mechanisms that govern their performance. This work was launched with the chief targets of establishing key competence in gear lubrication. LÄS MER

4. 23. Atomic Layer Deposition and Immobilised Molecular Catalysts Studied by In and Ex Situ Electron Spectroscopy

   Författare :Payam Shayesteh; NanoLund: Centre for Nanoscience; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ambient pressure XPS; Catalysis; Heterogenisation; Atomic layer deposition; HfO2; Gas phase; TDMAHf; TDMAT; Fysicumarkivet A:2019:Shayesteh;

   Sammanfattning : The research work that I describe in my thesis deals with three different heterogenisation approaches for synthesising a heterogeneous transition metal catalyst used for direct C-H activation reactions. The three heterogenisation approaches considered in my research are: (1) heterogenisation of a molecular catalyst on a polymer support using covalent bonds, (2) heterogenisation of a catalyst on a reduced graphene oxide (rGO) support using non-covalent interactions and (3) immobilisation of a catalyst on an inorganic surface using covalent bonds and encapsulation in an inorganic matrix. LÄS MER

5. 24. Nanomechanics – Quantum Size Effects, Contacts, and Triboelectricity

   Författare :Martin Olsen; Jonas Örtegren; Håkan Olin; Per Gradin; Peter Glans; Rusen Yang; Mittuniversitetet; []
   Nyckelord :triboelectricity; adatom; ion; charge; mound; quantum size effect; triboelctric nanogenerator; TENG; wind driven; contact; nanomechanics; fri electron model; nanowire cantilever;

   Sammanfattning : Nanomechanics is different from the mechanics that we experience in everyday life. At the nano-scale, typically defined as 1 to 100 nanometers, some phenomena are of crucial importance, while the same phenomena can be completely neglected on a larger scale. LÄS MER

7. 25. The HiPIMS Process

   Författare :Daniel Lundin; Ulf Helmersson; Nils Brenning; Jeffrey A. Hopwood; Linköpings universitet; []
   Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : The work presented in this thesis involves experimental and theoretical studies related to a thin film deposition technique called high power impulse magnetron sputtering (HiPIMS), and more specifically the plasma properties and how they influence the coating. HiPIMS is an ionized physical vapor deposition technique based on conventional direct current magnetron sputtering (DCMS). LÄS MER