Sökning: "surface oxide"

Visar resultat 11 - 15 av 753 avhandlingar innehållade orden surface oxide.

1. 11. Surface Chemical Characteristics of Chromium-alloyed Steel Powder and the Role of Process Parameters during Sintering

   Författare :Dimitris Chasoglou; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbothermal reaction; sintering atmosphere; depth profiling; XPS AES; HR SEM EDX; water atomized powder; surface coverage; reduction oxidation; PM steels; sintering; Cr-Mn-spinel oxides; surface oxides;

   Sammanfattning : Powder Metallurgy (PM) is a cost efficient method suitable for sustainable production of structural parts that have strict dimensional tolerances and complex geometries. It has been a common practice to utilize Ni and Cu as alloying elements in PM steels, but the high and fluctuating prices of Ni and the concerns around it associated with health hazards as well as the difficulty in recycling Cu lead the PM industry to search for effective alternatives such as Cr and Mn. LÄS MER

3. 12. Vibrational Sum Frequency Spectroscopy Studies at the Air-Liquid Interface

   Författare :Eric Tyrode; Mark Rutland; Paul Davies; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sum Frequency Generation; SFG; VSFS; surfactant; adsorption; water; surface structure; hydration; surface tension; fluorosurfactants; liquid-air interface; poly ethylene oxide surfactants; surface molecular orientation; acetic acid.; Surface and colloid chemistry; Yt- och kolloidkemi;

   Sammanfattning : In this thesis the structure and hydration of small organic and amphipilic compounds adsorbed at the air-liquid interface, have been studied using the nonlinear optical technique Vibrational Sum Frequency Spectroscopy (VSFS). The second order nature of the sum frequency process makes this technique particularly surface sensitive and very suitable for interfacial studies, as molecules at the surface can be distinguished even in the presence of a vast excess of the same molecules in the bulk. LÄS MER

4. 13. Surface Interactions in Powder Injection Moulding

   Författare :Elisabeth Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; surfactants; powder injection moulding PIM ; rheology; steel powder; surface interactions; XPS; SIMS; adsorption; surface composition;

   Sammanfattning : Powder Injection Moulding (PIM) is an attractive technique for producing complex components in large quantities my means of powder technology. The process includes mixing powder with a suitable binder, usually a thermoplastic polymer. Because of the large attractive forces between small particles the powder can be agglomerated in the binder. LÄS MER

5. 14. Investigation of electrochemical properties and performance of stimulation/sensing electrodes for pacemaker applications

   Författare :Anna Norlin; Jinshan Pan; Dieter Scharnweber; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; pacemaker electrode; interfacial property; biomaterial; electrostimulation charge transfer mechanism; electrochemical impedance spectroscopy; transient processes; plasma electrolysis anodisation; porous niobium oxide; ruthenium oxide; nano-porous carbon; iridium oxide; titanium nitride; platinum; surface roughness; porous electrode; pacing impedance; electrode polarisation; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : People suffering from certain types of arrhythmia may benefit from the implantation of a cardiac pacemaker. Pacemakers artificially stimulate the heart by applying short electrical pulses to the cardiac tissue to restore and maintain a steady heart rhythm. By adjusting the pulse delivery rate the heart is stimulated to beat at desired pace. LÄS MER

7. 15. Surface Reactivity and Electronic Structure of Metal Oxides

   Författare :Anneli Önsten; Ulf Karlsson; Anne Borg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; oxides; surfaces; defects; cuprous oxide; zinc oxide; magnetite; water; OH; sulfur dioxide; photoelectron spectroscopy; scanning tunneling microscopy; Material physics with surface physics; Materialfysik med ytfysik;

   Sammanfattning : The foci of this thesis are the metal oxides Cu2O, ZnO and Fe3O4 and their interaction with water and sulfur dioxide (SO2). The intention is to study SO2-induced atmospheric corrosion on a molecular level. All studies are based on photoelectron spectroscopy (PES) and scanning tunneling microscopy (STM) measurements. LÄS MER