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Visar resultat 1 - 5 av 207 avhandlingar som matchar ovanstående sökkriterier.

1. 1. LiFeSO4F as a Cathode Material for Lithium-Ion Batteries : Synthesis, Structure, and Function

   Författare :Adam Sobkowiak; Fredrik Björefors; Kristina Edström; Anna Andersson; M. Rosa Palacin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Li-ion battery; cathode; LiFeSO4F; tavorite; triplite; synthesis; performance; structure; coating; PEDOT; XRD; Mössbauer spectrocopy; SEM; TEM; electrochemistry; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

   Sammanfattning : In this thesis, two recently discovered polymorphs of LiFeSO4F, adopting a tavorite- and triplite-type structure, were investigated as potential candidates for use as cathode materials in Li-ion batteries. The studies aimed at enriching the fundamental understanding of the synthetic preparations, structural properties, and electrochemical functionality of these materials. LÄS MER

3. 2. Hollow Cathode Deposition of Thin Films

   Författare :Lars-Erik Gustavsson; Ladislav Bárdoš; Hana Baránková; Claes Nender; Uppsala universitet; []
   Nyckelord :Electronics; Hollow cathode; Hybrid plasma; PVD; TiN films; Ferromagnetic substrates; Magnetized plasma; CrN films; Elektronik;

   Sammanfattning : Thin films of metals and compounds have a very wide range of applications today. Many of the deposition methods used for the production of such films utilize plasma to support the growth the film, e.g. by the supply of energy and the enhancement of reactivity. LÄS MER

4. 3. Design and Experiments with High Power Microwave Sources : The Virtual Cathode Oscillator

   Författare :Cecilia Möller; Nils Brenning; Stefan Silfverskiöld; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High Power Microwaves Vircator;

   Sammanfattning : High-Power Microwaves (HPM) can be used to intentionally disturb or destroy electronic equipment at a distance by inducing high voltages and currents.This thesis presents results from simulations and experiments with a narrow band HPM source, the vircator. LÄS MER

5. 4. Lithium-ion insertion in a V6O13 cathode

   Författare :Örjan Bergström; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; cathode material; vanadium oxide; lithium insertion; in situ X-ray diffraction; deformation electron density refinement; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : The transition metal oxide V6O13 is a promising cathode material for high-capacity lithium-polymer batteries in conjunction with a lithium-metal anode. The electro-chemical behaviour of V6O13 has its origin in the ability of the vanadium ions to change their-oxidation states, combined with the open nature of its crystal structure which allows lithium ions to diffuse through it. LÄS MER

7. 5. Modelling of cathode-plasma interaction in short high-intensity electric arc : Application to Gas Tungsten Arc Welding

   Författare :Alireza Javidi Shirvan; Isabelle Choquet; Håkan Nilsson; Armelle Vardelle; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Electric arc discharge; sheath; pre-sheath; Knudsen layer; doped refractory cathode; arc-cathode coupling; Gas Tungsten Arc simulation; OpenFOAM.; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

   Sammanfattning : In arc welding the quality of the weld is strongly influenced by the thermal history of the workpiece which is itself governed by the electric arc heat source. The models for predicting weld properties thus need a good evaluation of the distribution of the heat input from thearc to the workpiece. LÄS MER