Sökning: "charge redistribution"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden charge redistribution.

1. 1. Electronic effects at metallic surfaces and interfaces : image-state formation and charge redistribution

   Författare :Stella Papadia; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; effective-medium theory; charge redistribution; heat of solution; multiple-reflection; LDA; density-functional theory; image-state; image-potential-induced resonance; LMTO-ASA; exchange-corelation potential; jellium; metallic superlattices;

   Sammanfattning : .... LÄS MER

3. 2. Charge Accumulation in Hybrid High Voltage Insulation

   Författare :Mats Sjöberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric barrier; charge accumulation; high voltage; dielectric barrier discharge; dielectric coating; hybrid insulation; electric field distribution; discharge modelling; breakdown strength; charge conditioning;

   Sammanfattning : This thesis deals with the novel idea of controlling the electric stress or field distribution in a hybrid air - solid-dielectric high voltage insulation by promoting accumulation of surface charges on the internal interfacial layers in the combined (hybrid) dielectric structure. Primarily, applications are expected to be found in high voltage dc systems and as a method to improve the resistance against insulation failure by overvoltages, e. LÄS MER

4. 3. Topographical Impact on Space Charge Injection, Accumulation and Breakdown in Polymeric HVDC Cable Interfaces

   Författare :Espen Doedens; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; interfaces; XLPE; roughness; cable peelings; polymer surfaces; space charge; field enhancement factor; PEA; DC breakdown; extruded cable; roughness enhanced charge injection; HVDC; charge injection;

   Sammanfattning : Extruded HVDC cable systems feature a variety of interface types, for which physio-chemical properties will depend on the type of application. Such applications can be joints, terminations or the cable itself, all introducing different material combinations and manufacturing methods. LÄS MER

5. 4. 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. 5. Cooperative Lithium-Ion Insertion Mechanisms in Cathode Materials for Battery Applications

   Författare :Helen Björk; Tsutomo Ohzuku; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Li-ion battery; cathode materials; single-crystal; X-ray diffraction; delithiation; superlattice; phase transformation; charge-ordering; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Understanding lithium-ion insertion/extraction mechanisms in battery electrode materials is of crucial importance in developing new materials with better cycling performance. In this thesis, these mechanisms are probed for two different potential cathode materials by a combination of electrochemical and single-crystal X-ray diffraction studies. LÄS MER